1
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Kumar S, Sarma M. Dissociative electron attachment to halogenated nucleotides: a quest for better radiosensitizers. Phys Chem Chem Phys 2024. [PMID: 39328041 DOI: 10.1039/d4cp02258k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2024]
Abstract
Tumor hypoxia hampers radiotherapy efficacy, necessitating radiosensitizers. Substituted nucleobases offer advantages as radiosensitizers. They can be incorporated into DNA with minimal gene-expression alteration, selectively targeting tumor cells and having lower toxicity to normal tissues. They possess higher electron affinity than native DNA, facilitating rapid electron attachment for cancer-cell damage. Despite advancements, exploration beyond uracil nucleobases remains limited. Herein, we investigated electron attachment to potential radiosensitizers, specifically 5-halo-2'-deoxycytidine-3'-monophosphates (5X-3'-dCMPH). Our findings indicate that 5X-3'-dCMPH nucleotides possess higher electron affinity than unsubstituted 3'-dCMPH, suggesting halogenated nucleotides are better electron acceptors. Moreover, the high vertical detachment energy (VDE) implies minimal auto-detachment, and the dissociative electron attachment (DEA) pathways suggest that dehalogenation is the favored process for halogenated systems, supported by low dissociation barriers. Notably, 5Br-3'-dCMPH and 5I-3'-dCMPH exhibit nearly barrier-free dissociation after electron attachment, and thus, they may preferentially act as superior radiosensitizers.
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Affiliation(s)
- Shubham Kumar
- Department of Chemistry, Indian Institute of Technology Guwahati, North-Guwahati, Guwahati-781039, India.
| | - Manabendra Sarma
- Department of Chemistry, Indian Institute of Technology Guwahati, North-Guwahati, Guwahati-781039, India.
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2
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Zhang X, Chang M, Ni T, Liu S, Li W, Xu X. CuBr 2-mediated dehydrogenative [4+2] annulation of 1-naphthyl-1,3-indandiones and alkenes. Chem Commun (Camb) 2024; 60:9070-9073. [PMID: 39101974 DOI: 10.1039/d4cc02386b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/06/2024]
Abstract
Intermolecular annulation reactions of 1-naphthyl-1,3-indandiones with alkenes proceed efficiently in the presence of a copper catalyst to generate spirocarbocycle compounds. Various spirocyclic molecules bearing an all-carbon quaternary center could be obtained by this novel method with good yields, excellent regioselectivity, and good functional group tolerance. A radical mechanism is proposed based on the HRMS analysis results of control experiments.
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Affiliation(s)
- Xu Zhang
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China.
| | - Mengfan Chang
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China.
| | - Tongtong Ni
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China.
| | - Shuhan Liu
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China.
| | - Wenguang Li
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China.
| | - Xuefeng Xu
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China.
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3
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Yan S, Zhang R, Ning C. Precision Measurement of the Electron Affinity of Chlorine via High-Resolution Photoelectron Spectroscopy. J Phys Chem Lett 2024; 15:7735-7739. [PMID: 39046310 DOI: 10.1021/acs.jpclett.4c01821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
Chlorine (Cl2) is a diatomic molecule used as an important industrial gas. However, the electron affinity (EA) of Cl2, a fundamental parameter for understanding chemical reactions, has no accurate experimental result available. The latest result of the EA value of Cl2 is 2.50(20) eV reported in 1983. In the present work, we report the precision measurement of the EA of Cl2 with the successive difference method via the high-resolution photoelectron spectroscopy of cryogenically cold chlorine anions Cl2-. The EA of Cl2 is determined to be 19432(9) cm-1 or 2.4093(11) eV.
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Affiliation(s)
- Shuaiting Yan
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Rui Zhang
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Chuangang Ning
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
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4
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McGinnis KR, McGee CJ, Sommerfeld T, Jarrold CC. Anion Photoelectron Imaging Spectroscopy of C 6F 5X - (X = F, Cl, Br, I). J Phys Chem A 2024; 128:5646-5658. [PMID: 38980699 DOI: 10.1021/acs.jpca.4c03434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The photoelectron (PE) spectra of C6F5X- (X = Cl, Br, I) and computational results on the anions and neutrals are presented and compared to previously reported results on C6F6- [McGee, C. J. J. Phys. Chem. A 2023, 127, 8556-8565.]. The spectra all exhibit broad, vibrationally unresolved detachment transitions, indicating that the equilibrium structures of the anions are significantly different from the neutrals. The PE spectrum of C6F5Cl- exhibits a parallel photoelectron angular distribution (PAD), similar to that of the previously reported C6F6- spectrum, while the PE spectra of C6F5Br- and C6F5I- have isotropic PADs, and also exhibit a prominent X- PE feature due to photodissociation of C6F5X- resulting in X- formation. Identification of the C6F5X- detachment transition origins, which is equivalent to the neutral electron affinity (EA), in all three cases is difficult, since the broadness of the detachment feature is accompanied by vanishingly small detachment cross section near the origin. Upper limits on the EAs were determined to be 1.70 eV for C6F5Cl, 2.10 eV for C6F5Br, and 2.00 eV for C6F5I, all significantly higher than the 0.76 eV upper limit determined for C6F6 with the same experiment. The broad detachment transitions are consistent with computational results, which predict very large differences between the neutral and anionic C-X (X = Cl, Br, I) bond lengths. Based on differences between the MBIS atom charges in the anions and neutrals, the excess charge in the anion is on the unique C atom and X, in contrast to the nonplanar C2v structured C6F6- anion, for which the charge is delocalized over the molecule. In C6F5Cl-, the C-Cl bond is predicted to be bent out of the plane, while both C6F5Br- and C6F5I- are predicted to be planar on average. The impact of the interruption of the symmetry in the hexafluorobenzene neutral and anion on the molecular and electronic structure of C6F5X/C6F5X- is considered, as well as the possible dissociative state leading to X- (X = Br, I) formation, and the nature of the C-X bond.
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Affiliation(s)
- Kristen Rose McGinnis
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Conor J McGee
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Thomas Sommerfeld
- Department of Chemistry and Physics, Southeast Louisiana University, SLU 10878, Hammond, Louisiana 70402, United States
| | - Caroline Chick Jarrold
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
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5
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Fu C, Du K, Xue J, Xin H, Zhang J, Li H. Mechanisms of acid generation from ionic photoacid generators for extreme ultraviolet and electron beam lithography. Phys Chem Chem Phys 2024; 26:18547-18556. [PMID: 38805008 DOI: 10.1039/d4cp01814a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Photoacid generators (PAGs) are important components of chemically amplified resists. The properties of PAGs directly affect the sensitivity of photoresists, line edge roughness, and resolution. Understanding the photoacid generation process in extreme ultraviolet (EUV) and electron beam (EB) lithography is helpful for photoresist design. However, the microscopic mechanisms remain largely unclear and the large variety in the molecular structure of PAGs presents a challenge to overcome. In this work, we investigate the microscopic processes of photoacid production of ionic PAGs for EUV and EB lithography. The PAG dissociation pathway is found to depend on the molecular structure and conformations. The processes of photoacid production and by-product generation are also revealed. The results contribute to a better understanding of the photochemical reactions in EUV and EB lithography, providing insights into the molecular design of novel PAGs and photoresists.
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Affiliation(s)
- Chengbin Fu
- School of Microelectronics, Shanghai University, Shanghai 201800, China.
- Department of Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Kun Du
- School of Microelectronics, Shanghai University, Shanghai 201800, China.
| | - Jie Xue
- School of Microelectronics, Shanghai University, Shanghai 201800, China.
| | - Hanshen Xin
- School of Microelectronics, Shanghai University, Shanghai 201800, China.
| | - Jianhua Zhang
- School of Microelectronics, Shanghai University, Shanghai 201800, China.
| | - Haoyuan Li
- School of Microelectronics, Shanghai University, Shanghai 201800, China.
- Department of Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China
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6
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Jia Y, Guan Q, Chu C, Zhang L, Neisiany RE, Gu S, Sun J, You Z. A fluorine-based strong and healable elastomer with unprecedented puncture resistance for high performance flexible electronics. Sci Bull (Beijing) 2024; 69:1875-1886. [PMID: 38616151 DOI: 10.1016/j.scib.2024.03.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 02/17/2024] [Accepted: 03/13/2024] [Indexed: 04/16/2024]
Abstract
There is usually a trade-off between high mechanical strength and dynamic self-healing because the mechanisms of these properties are mutually exclusive. Herein, we design and fabricate a fluorinated phenolic polyurethane (FPPU) elastomer based on octafluoro-4,4'-biphenol to overcome this challenge. This fluorine-based motif not only tunes interchain interactions through π-π stacking between aromatic rings and free-volume among polymer chains but also improves the reversibility of phenol-carbamate bonds via electron-withdrawing effect of fluorine atoms. The developed FPPU elastomer shows the highest recorded puncture energy (648.0 mJ), high tensile strength (27.0 MPa), as well as excellent self-healing efficiency (92.3%), along with low surface energy (50.9 MJ m-2), notch-insensitivity, and reprocessability compared with non-fluorinated counterpart biphenolic polyurethane (BPPU) elastomer. Taking advantage of the above-mentioned merits of FPPU elastomer, we prepare an anti-fouling triboelectric nanogenerator (TENG) with a self-healable, and reprocessable elastic substrate. Benefiting from stronger electron affinity of fluorine atoms than hydrogen atoms, this electronic device exhibits ultrahigh peak open-circuit voltage of 302.3 V compared to the TENG fabricated from BPPU elastomer. Furthermore, a healable and stretchable conductive composite is prepared. This research provides a distinct and general pathway toward constructing high-performance elastomers and will enable a series of new applications.
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Affiliation(s)
- Yujie Jia
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Institute of Functional Materials, College of Materials Science and Engineering, Research Base of Textile Materials for Flexible Electronics and Biomedical Applications (China Textile Engineering Society), Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Donghua University, Shanghai 201620, China
| | - Qingbao Guan
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Institute of Functional Materials, College of Materials Science and Engineering, Research Base of Textile Materials for Flexible Electronics and Biomedical Applications (China Textile Engineering Society), Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Donghua University, Shanghai 201620, China
| | - Chengzhen Chu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Institute of Functional Materials, College of Materials Science and Engineering, Research Base of Textile Materials for Flexible Electronics and Biomedical Applications (China Textile Engineering Society), Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Donghua University, Shanghai 201620, China
| | - Luzhi Zhang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Institute of Functional Materials, College of Materials Science and Engineering, Research Base of Textile Materials for Flexible Electronics and Biomedical Applications (China Textile Engineering Society), Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Donghua University, Shanghai 201620, China
| | - Rasoul Esmaeely Neisiany
- Biotechnology Centre, Silesian University of Technology, Gliwice 44-100, Poland; Department of Polymer Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran
| | - Shijia Gu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Institute of Functional Materials, College of Materials Science and Engineering, Research Base of Textile Materials for Flexible Electronics and Biomedical Applications (China Textile Engineering Society), Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Donghua University, Shanghai 201620, China
| | - Junfen Sun
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Institute of Functional Materials, College of Materials Science and Engineering, Research Base of Textile Materials for Flexible Electronics and Biomedical Applications (China Textile Engineering Society), Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Donghua University, Shanghai 201620, China.
| | - Zhengwei You
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Institute of Functional Materials, College of Materials Science and Engineering, Research Base of Textile Materials for Flexible Electronics and Biomedical Applications (China Textile Engineering Society), Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Donghua University, Shanghai 201620, China.
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7
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Abdoul-Carime H, Thiam G, Rabilloud F. Low Energy (<10 eV) Electron Collision with Benzonitrile-CCl 4 Admixture: A Combined Theoretical and Experimental Study. Chemphyschem 2024:e202400287. [PMID: 38923142 DOI: 10.1002/cphc.202400287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 06/22/2024] [Accepted: 06/24/2024] [Indexed: 06/28/2024]
Abstract
Benzonitrile (BZN) and carbon tetrachloride (CCl4) are versatile solvents used as a precursor for the synthesis of many products. As multi-usage molecules, these compounds may be involved in sustainable chemistry processes such as the cold plasma techniques for which the generated electrons are known to be responsible for reactions. Therefore, it is desirable to explore the interaction of low energy electrons with the co-compounds in the gas phase. The production of chlorine and cyanine anions, initiated by the electron collision with CCl4 and BZN, respectively, undergo nucleophilic substitution SN2 reaction with the precursors molecules for the synthesis of chlorobenzene and tricholoacetonitrile. The mechanism of fragmentation of benzonitrile and the synthesis reactions are rationalized by DFT calculations. The yield of the cyanine anion produced from the ion reaction increases with the temperature of the admixture gas, probed in the 25-100 °C temperature range. The present work may contribute to a potential process for the production of chlorobenzene for instance via (cold) plasma techniques.
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Affiliation(s)
- H Abdoul-Carime
- Université Claude Bernard Lyon 1, Institut de Physique des 2 Infinis, CNRS/IN2P3, UMR5822, F-69003, Lyon, France
| | - Guillaume Thiam
- Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, UMR5306, F-69622, Villeurbanne, France
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Via Elce di Sotto, 8, 06123, Perugia, Italy
| | - Franck Rabilloud
- Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, UMR5306, F-69622, Villeurbanne, France
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8
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Opoku E, Pawłowski F, Ortiz JV. Ab Initio Electron Propagators with an Hermitian, Intermediately Normalized Superoperator Metric Applied to Vertical Electron Affinities. J Phys Chem A 2024; 128:4730-4749. [PMID: 38814678 DOI: 10.1021/acs.jpca.4c02050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
New-generation ab initio electron propagator methods for calculating electron detachment energies of closed-shell molecules and anions have surpassed their predecessors' accuracy and computational efficiency. Derived from an Hermitian, intermediately normalized superoperator metric, these methods contain no adjustable parameters. To assess their versatility, a standard set (NIST-50-EA) of 50 vertical electron affinities of small closed-shell molecules based on NIST reference data has been created. Errors with respect to reference data on 23 large, conjugated organic photovoltaic (OPV23) molecules have also been analyzed. All final states are valence anions that correspond to electron affinities between 0.2 and 4.2 eV. For a given scaling of the arithmetic bottleneck, the new-generation methods obtain the lowest mean absolute errors (MAEs). The best methods with fifth-power arithmetic scaling realize MAEs below 0.1 eV. Composite models comprising cubically and quintically scaling calculations executed with large and small basis sets, respectively, produce OPV23 MAEs near 0.05 eV. The accuracy of quintically scaling methods executed with large basis sets is thereby procured with reduced computational effort. New-generation results obtained with and without the diagonal self-energy approximation in the canonical Hartree-Fock basis have been compared. These results indicate that Dyson orbitals closely resemble canonical Hartree-Fock orbitals multiplied by the square root of a probability factor above 0.85.
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Affiliation(s)
- Ernest Opoku
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312, United States
| | - Filip Pawłowski
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312, United States
| | - J V Ortiz
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312, United States
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9
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Clarke CJ, Verlet JRR. Dynamics of Anions: From Bound to Unbound States and Everything In Between. Annu Rev Phys Chem 2024; 75:89-110. [PMID: 38277700 DOI: 10.1146/annurev-physchem-090722-125031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2024]
Abstract
Gas-phase anions present an ideal playground for the exploration of excited-state dynamics. They offer control in terms of the mass, extent of solvation, internal temperature, and conformation. The application of a range of ion sources has opened the field to a vast array of anionic systems whose dynamics are important in areas ranging from biology to star formation. Here, we review recent experimental developments in the field of anion photodynamics, demonstrating the detailed insight into photodynamical and electron-capture processes that can be uncovered. We consider the electronic and nuclear ultrafast dynamics of electronically bound excited states along entire reaction coordinates; electronically unbound states showing that photochemical concepts, such as chromophores and Kasha's rule, are transferable to electron-driven chemistry; and nonvalence states that straddle the interface between bound and unbound states. Finally, we consider likely developments that are sure to keep the field of anion dynamics buoyant and impactful.
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Affiliation(s)
- Connor J Clarke
- Department of Chemistry, Durham University, Durham, United Kingdom;
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham, United Kingdom;
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10
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Doust Mohammadi M, Bhowmick S, Maisser A, Schmidt-Ott A, Biskos G. Electronic properties and collision cross sections of AgO kH m± ( k, m = 1-4) aerosol ionic clusters. Phys Chem Chem Phys 2024; 26:14547-14560. [PMID: 38721799 DOI: 10.1039/d3cp05499c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
Experimental evidence shows that hydroxylated metal ions are often produced during cluster synthesis by atmospheric pressure spark ablation. In this work, we predict the ground state equilibrium structures of AgOkHm± clusters (k and m = 1-4), which are readily produced when spark ablating Ag, using the coupled cluster with singles and doubles (CCSD) method. The stabilization energy of these clusters is calculated with respect to the dissociation channel having the lowest energy, by accounting perturbative triples corrections to the CCSD method. The interatomic interactions in each of the systems have been investigated using the frontier molecular orbital (FMO), natural bond orbital (NBO) and quantum theory of atoms in molecules (QTAIM) methods. Many of the ground states of these ionic clusters are found to be stable, corroborating experimental observations. We find that clusters having singlet spin states are more stable in terms of dissociation than the clusters that have doublet or triplet spin states. Our calculations also indicate a strong affinity of the ionic and neutral Ag atom towards water and hydroxyl radicals or ions. Many 3-center, 4-electron (3c/4e) hyperbonds giving rise to more than one resonance structure are identified primarily for the anionic clusters. The QTAIM analysis shows that the O-H and O-Ag bonds in the clusters of both polarities are respectively covalent and ionic. The FMO analysis indicates that the anionic clusters are more reactive than the cationic ones. Using the cluster structures predicted by the CCSD method, we calculate the collision cross sections of the AgOkHm± family, with k and m ranging from 1 to 4, by the trajectory method. In turn, we predict the electrical mobilities of these clusters when suspended in helium at atmospheric pressure and compare them with experimental measurements.
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Affiliation(s)
- Mohsen Doust Mohammadi
- Climate & Atmosphere Research Centre, The Cyprus Institute, 20 Konstantinou Kavafi Street, Nicosia 2121, Cyprus.
| | - Somnath Bhowmick
- Climate & Atmosphere Research Centre, The Cyprus Institute, 20 Konstantinou Kavafi Street, Nicosia 2121, Cyprus.
| | - Anne Maisser
- Climate & Atmosphere Research Centre, The Cyprus Institute, 20 Konstantinou Kavafi Street, Nicosia 2121, Cyprus.
| | - Andreas Schmidt-Ott
- Climate & Atmosphere Research Centre, The Cyprus Institute, 20 Konstantinou Kavafi Street, Nicosia 2121, Cyprus.
- Faculty of Applied Sciences, Delft University of Technology, Delft, 2629 HZ, The Netherlands
| | - George Biskos
- Climate & Atmosphere Research Centre, The Cyprus Institute, 20 Konstantinou Kavafi Street, Nicosia 2121, Cyprus.
- Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, 2628 CN, The Netherlands
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11
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Sedmidubská B, Kočišek J. Interaction of low-energy electrons with radiosensitizers. Phys Chem Chem Phys 2024; 26:9112-9136. [PMID: 38376461 DOI: 10.1039/d3cp06003a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
We provide an experimentalist's perspective on the present state-of-the-art in the studies of low-energy electron interactions with common radiosensitizers, including compounds used in combined chemo-radiation therapy and their model systems. Low-energy electrons are important secondary species formed during the interaction of ionizing radiation with matter. Their role in the radiation chemistry of living organisms has become an important topic for more than 20 years. With the increasing number of works and reviews in the field, we would like to focus here on a very narrow area of compounds that have been shown to have radio-sensitizing properties on the one hand, and high reactivity towards low-energy electrons on the other hand. Gas phase experiments studying electron attachment to isolated molecules and environmental effects on reaction dynamics are reviewed for modified DNA components, nitroimidazoles, and organometallics. In the end, we provide a perspective on the future directions that may be important for transferring the fundamental knowledge about the processes induced by low-energy electrons into practice in the field of rational design of agents for concomitant chemo-radiation therapy.
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Affiliation(s)
- Barbora Sedmidubská
- J. Heyrovský Institute of Physical Chemistry of the CAS, Dolejškova 3, 182223 Prague, Czech Republic.
- Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Břehová 7, 11519 Prague, Czech Republic
- Institut de Chimie Physique, UMR 8000 CNRS and Faculté des sciences d'Orsay, Université Paris Saclay, F-91405 Orsay Cedex, France
| | - Jaroslav Kočišek
- J. Heyrovský Institute of Physical Chemistry of the CAS, Dolejškova 3, 182223 Prague, Czech Republic.
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12
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Abeysooriya DNKH, White NJ, Workman KT, Dupuy JA, Gichuhi WK. Cyanocyclopentadiene-Annulated Polycyclic Aromatic Radical Anions: Predicted Negative Ion Photoelectron Spectra and Singlet-Triplet Energies of Cyanoindene and Cyanofluorene Radical Anions. J Phys Chem A 2024. [PMID: 38437617 DOI: 10.1021/acs.jpca.3c08312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2024]
Abstract
Isomer-specific negative ion photoelectron spectra (NIPES) of cyanoindene (C9H7CN) and cyanofluorene (C14H9N), acquired through the computation of Franck-Condon (FC) factors that utilize harmonic vibrational frequencies and normal mode vectors derived from density functional theory (DFT) at the B3LYP/aug-cc-pVQZ and 6-311++G(2d,2p) basis sets, are reported. The adiabatic electron affinity (EA) values of the ground singlet (S0) and the lowest lying triplet (T1) states are used to predict site-specific S0-T1 energies (ΔEST). The vibrational spectra of the S0 and T1 states are typified by ring distortion and ring C-C stretching vibrational progressions. Among all the S0 isomers in C9H7CN, the 2-cyanoindene (2-C9H7CN) is found to be the most stable at an EA of 0.716 eV, with the least stable isomer being the 1-C9H7CN at an EA of 0.208 eV. In C14H9N, the most stable S0 isomer, 2-cyanofluorene (2-C14H9N), has an EA of 0.781 eV. The least stable S0 isomer in C14H9N is the 9-C14H9N, with an EA of 0.364 eV. The FC calculations are designed to mimic simulations that would be performed to aid in the analysis of experimental spectra obtained in NIPE spectroscopic techniques. The vibrational spectra, adiabatic EAs, and ΔEST values reported in this study are intended to act as a guide for future gas-phase ion spectroscopic experiments and astronomical searches, especially with regard to the hitherto largely unexplored C14H9N isomers.
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Affiliation(s)
- Dushmantha N Koku Hannadige Abeysooriya
- Department of Chemistry, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee 38505, United States
- School of Environmental Studies, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee 38505, United States
| | - Nolan J White
- Department of Chemistry, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee 38505, United States
- Department of Chemical Engineering, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee 38505, United States
| | - Kie T Workman
- Department of Chemistry, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee 38505, United States
- Department of Chemical Engineering, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee 38505, United States
| | - Jonathan A Dupuy
- Department of Chemistry, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee 38505, United States
| | - Wilson K Gichuhi
- Department of Chemistry, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee 38505, United States
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13
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Wang XJ, Ding YH, Tian X. Achieving Accuracy and Economy for Calculating Vertical Detachment Energies of Molecular Anions: A Model Chemistry Composite Methods. Chemphyschem 2024; 25:e202300642. [PMID: 38165629 DOI: 10.1002/cphc.202300642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/29/2023] [Accepted: 01/02/2024] [Indexed: 01/04/2024]
Abstract
The vertical detachment energy (VDE) is a vital factor for predicting the stability of anions that have important applications in the atom, molecule and cluster science. Due to the synthetic or characterization difficulty of anions, accurate and efficient predictions of VDE independent of laboratory data have always been an appealing task to remedy the experimental deficiencies. Unfortunately, the generally adopted CCSD(T) and electron propagator theory (EPT) methods have respectively been proven to be reliable but very cost-expensive, and cost-effective but sometimes problematic when Koopman's theorem is invalid. Here, we for the first time introduced and benchmarked a series of model chemistry composite methods (e. g., CBS-QB3, G4 and W1BD) on calculating VDE for 57 molecular anions. Notably, CBS-QB3 exceeds the accuracy of CCSD(T) while approaching the economy of EPT. Therefore, we highly recommend the composite method CBS-QB3 to compute VDEs for molecular anions in the attractive "killing two birds with one stone" manner.
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Affiliation(s)
- Xiao-Juan Wang
- Key Laboratory of Carbon Materials of Zhejiang Province, Wenzhou Key Lab of Advanced Energy Storage and Conversion, Zhejiang Province Key Lab of Leather Engineering, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, 325035, P. R. China
| | - Yi-Hong Ding
- Key Laboratory of Carbon Materials of Zhejiang Province, Wenzhou Key Lab of Advanced Energy Storage and Conversion, Zhejiang Province Key Lab of Leather Engineering, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, 325035, P. R. China
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, 130023, P. R. China
| | - Xiao Tian
- School of Mathematics and Science, Hebei GEO University, Shijiazhuang, 050031, P. R. China
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Altalhi WAO, Chan B, O'Hair RAJ. Methide Affinity Scale: Key Thermodynamic Data Underpinning Catalysis, Organic Synthesis, and Organometallic and Polymer Chemistry. J Phys Chem A 2024; 128:977-988. [PMID: 38295100 DOI: 10.1021/acs.jpca.3c05974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
Methide transfer reactions play important roles in many areas of chemistry, including the Grignard reaction, in the transmetalation steps of metal-catalyzed cross-coupling reactions, and in the generation of cationic metal polymerization catalysts. Methide affinities (MAs) are the key thermodynamic quantity that underpin such reactions, and yet comprehensive methide affinity scales are poorly developed. Here, B3LYP-D3BJ/def2-TZVP calculations are used to calculate the energy changes (MAs) for cations (MeZ → Z+ + Me-), neutrals (MeY- → Y + Me-), and anions (MeX2- → X- + Me-) derived from permethyl species of all group s and p elements. The MAs range from 2525.8 for the singlet cation F+ to -820.4 kJ/mol for the tetramethylborate anion, Me4B-. The cations show the clearest trends: the MAs in all cases decrease going down the group, while moving across a period, the MAs increase from group 1 to group 2 and then decrease for group 3, remaining about the same or with a modest increase moving to group 4, and then continue to increase across a period to a maximum for the halogens (group 17). The anions and dianions are sensitive to hypervalency; those elements that cannot expand the octet have very unfavorable MAs (e.g., MA of Me4C requires the formation of Me5C- and of Me4B- requires the formation of Me5B2-). To address whether the anion MeY- and dianion MeZ2- are stable, the vertical detachment energies of the anions and dianions were calculated. All of the anions are thermodynamically stable with respect to electron loss, except for Me4N-, while the dianions are all thermodynamically unstable with respect to electron loss. The kinetic stability of the dianions with respect to methide and electron loss was also evaluated for the lowest MAs. The only dianions that might be kinetically stable and observable in the gas phase are Me4Ca2-, Me4Sr2-, and Me4Ba2-. The dianion CF3CaF32- is predicted to be both thermodynamically and kinetically stable in the gas phase.
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Affiliation(s)
- Weam A O Altalhi
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Melbourne, Victoria 3010, Australia
- Department of Chemistry, Prince Sattam Bin Abdulaziz University, Hotat Bani Tamim 16511, Saudi Arabia
| | - Bun Chan
- Graduate School of Engineering, Nagasaki University, Bunkyo 1-14, Nagasaki 852-8521, Japan
- Computational Molecular Science Research Team, RIKEN Center for Computational Science, 7-1-26 minatojima-minami, Cyuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Melbourne, Victoria 3010, Australia
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15
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Lewis TWR, Sweeny BC, Viggiano AA, Shuman NS, Ard SG. Temperature-Dependent Kinetics for the Reactions of Fe n- ( n = 2-17) and Fe xNi y- ( x + y = 3-9) with O 2: Comparison of Pure and Mixed Metal Clusters with Relevance to Meteor Radio Afterglows and Surface Oxidation. J Phys Chem A 2024; 128:439-448. [PMID: 38175962 DOI: 10.1021/acs.jpca.3c07368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Rate constants and product branching fractions were measured from 300-600 K for Fen- + O2 (n = 2-17) and for 300-500 K for FexNiy- + O2 (x + y = 3-9) using a selected-ion flow tube (SIFT) apparatus. Rate constants for 46 species are reported. All rate constants increased with increasing temperature, and several were in excess of the Langevin-Gioumousis-Stevenson (LGS) capture rate at elevated temperatures. As with previously studied transition metal anion oxidation reactions, the collision limit is treated as the sum of the LGS limit along with a hard-sphere contribution, allowing for determination of activation energies. These values are compared to each other along with previous results for Nin-. Measured rate constants for all three series (Fen-, Nin-, and FexNy-) vary over a relatively narrow range (1-5 × 10-10 cm3 s-1 at 300 K) being at least 15% of the collision rate constant. All reaction rate constants increase with temperature, described by small activation energies of 0.5-4 kJ mol-1. The data are consistent with an anticorrelation between the electron binding energy and rate constant, previously noted in other systems. The Fen- reaction produces a larger population of higher energy electrons than do the Nin- reactions, with FexNiy- producing an intermediate amount. The results suggest that the overall rate constant is limited by a small energetic barrier located at a large internuclear distance where electrostatic forces dominate, causing the potentials to be similar across systems, while the product formation is determined by the shorter-range, valence portion of the potential, which varies widely between systems.
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Affiliation(s)
- Tucker W R Lewis
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117, United States
| | - Brendan C Sweeny
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117, United States
| | - Albert A Viggiano
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117, United States
| | - Nicholas S Shuman
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117, United States
| | - Shaun G Ard
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117, United States
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16
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Simons J. An environmental impact statement for molecular anions. Phys Chem Chem Phys 2024; 26:1564-1586. [PMID: 38126406 DOI: 10.1039/d3cp04842j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
A molecular anion's (MA's) chemical reactivity and physical behavior can be quite different when it is surrounded by other molecules than when it exists in isolation. This sensitivity to the surrounding environment is especially high for anions because their outermost valence electrons are typically loosely bound and exist in rather spatially diffuse orbitals, allowing even weak intermolecular interactions arising from the environment to have strong effects. This Perspective offers illustrations of such sensitivity for a variety of cases including (i) the effect of solvation on electron binding energies, (ii) how some "well known" anions need to have solvent molecules around to even exist as stable species, (iii) how internal Coulomb repulsions within a multiply charged MA can provide temporary stability toward electron loss, (iv) how MAs arrange themselves spatially near liquid/vapor interfaces in manners that can produce unusual reactivity, (v) how nearby cationic sites can facilitate electron attachment to form a MA site elsewhere, (vi) how internal vibrational or rotational energy can make a MA detach an electron.
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Affiliation(s)
- Jack Simons
- Henry Eyring Center for Theoretical Chemistry, Department of Chemistry, University of Utah, Salt Lake City, UT, 84112, USA.
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Sikorska C. Design and Investigation of Superatoms for Redox Applications: First-Principles Studies. MICROMACHINES 2023; 15:78. [PMID: 38258197 PMCID: PMC10820084 DOI: 10.3390/mi15010078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/24/2024]
Abstract
A superatom is a cluster of atoms that acts like a single atom. Two main groups of superatoms are superalkalis and superhalogens, which mimic the chemistry of alkali and halogen atoms, respectively. The ionization energies of superalkalis are smaller than those of alkalis (<3.89 eV for cesium atom), and the electron affinities of superhalogens are larger than that of halogens (>3.61 eV for chlorine atom). Exploring new superalkali/superhalogen aims to provide reliable data and predictions of the use of such compounds as redox agents in the reduction/oxidation of counterpart systems, as well as the role they can play more generally in materials science. The low ionization energies of superalkalis make them candidates for catalysts for CO2 conversion into renewable fuels and value-added chemicals. The large electron affinity of superhalogens makes them strong oxidizing agents for bonding and removing toxic molecules from the environment. By using the superatoms as building blocks of cluster-assembled materials, we can achieve the functional features of atom-based materials (like conductivity or catalytic potential) while having more flexibility to achieve higher performance. This feature paper covers the issues of designing such compounds and demonstrates how modifications of the superatoms (superhalogens and superalkalis) allow for the tuning of the electronic structure and might be used to create unique functional materials. The designed superatoms can form stable perovskites for solar cells, electrolytes for Li-ion batteries of electric vehicles, superatomic solids, and semiconducting materials. The designed superatoms and their redox potential evaluation could help experimentalists create new materials for use in fields such as energy storage and climate change.
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Affiliation(s)
- Celina Sikorska
- Faculty of Chemistry, University of Gdańsk, Fahrenheit Union of Universities in Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland;
- Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
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18
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Chi C, Yang Z, Zeng B, Qin Q, Meng L. Spectroscopic characterization of heteronuclear iron-chromium carbonyl cluster anions. Phys Chem Chem Phys 2023; 25:32173-32183. [PMID: 37986618 DOI: 10.1039/d3cp04248k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Infrared photodissociation spectroscopy has been used to investigate CrFe(CO)n- (n = 4-9) clusters in the gas phase. Comparison of the observed spectra in the carbonyl stretching frequency region with those predicted for low-lying isomers by DFT calculations showed that the observed CrFe(CO)n- (n = 4-8) clusters could be characterized to have Cr-Fe bonded (OC)4Fe-Cr(CO)n-4 structures. The coexistence of isomers with the (OC)Fe-Cr(CO)5 and (OC)3Fe-Cr(CO)4 structures was also observed for CrFe(CO)6- and CrFe(CO)7- anions, respectively. The CrFe(CO)n- (n = 4-8) complexes were strongly bonded systems. The CrFe(CO)8- complex was a coordination-saturated cluster, and the CrFe(CO)9- anion was characterized to contain a CrFe(CO)8- core tagged by one CO molecule. Bonding analysis revealed that the Cr-Fe bonds in the CrFe(CO)n- (n = 4-8) clusters were predominantly σ-type single bonds. The iron center in the Fe(CO)4 moiety and the chromium center in the Cr(CO)5 moiety fulfilled the 18-electron configuration for the CrFe(CO)n- (n = 4-6) clusters. As in the CrFe(CO)n- (n = 7, 8) complexes, the iron center in the Fe(CO)4 moiety exhibited a 17-electron configuration, while the chromium center in the Cr(CO)4 moiety exhibited a 16-electron configuration. These findings provide valuable insights into the structure and bonding mechanism of heterometallic carbonyl clusters.
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Affiliation(s)
- Chaoxian Chi
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, School of Material Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang Province 315211, China.
- School of Chemistry and Materials Science, East China University of Technology, Nanchang, Jiangxi Province 330013, China.
| | - Zhixiang Yang
- School of Chemistry and Materials Science, East China University of Technology, Nanchang, Jiangxi Province 330013, China.
| | - Bin Zeng
- School of Chemistry and Materials Science, East China University of Technology, Nanchang, Jiangxi Province 330013, China.
| | - Qifeng Qin
- School of Chemistry and Materials Science, East China University of Technology, Nanchang, Jiangxi Province 330013, China.
| | - Luyan Meng
- School of Chemistry and Materials Science, East China University of Technology, Nanchang, Jiangxi Province 330013, China.
- Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo, Zhejiang, 315020, China
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Schopper N, Landmann J, Sprenger JAP, Zapf L, Bertermann R, Ignat'ev NV, Finze M. Alkylcyanoborate Anions: Building Blocks for Fluorine-Free Low-Viscosity, Electrochemically and Thermally Stable Ionic Liquids. Chemistry 2023; 29:e202301497. [PMID: 37395305 DOI: 10.1002/chem.202301497] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/01/2023] [Accepted: 07/03/2023] [Indexed: 07/04/2023]
Abstract
A set of mixed-substituted potassium alkylcyano- and alkylcyanofluoroborates has been synthesized using easily accessible starting compounds and characterized by elemental analysis, NMR and vibrational spectroscopy, and mass spectrometry. In addition, single-crystal structures of salts of the cyanoborate anions have been derived from X-ray diffraction experiments. The 1-ethyl-3-methylimidazolium room temperature ionic liquids ([EMIm]+ -RTILs) with the new borate anions have been synthesized and their physicochemical properties, that is, high thermal and electrochemical stability, low viscosity, and high conductivity, have been compared to the properties of related [EMIm]+ -RTILs. The influence of the different alkyl substituents at boron has been assessed. The exemplary study on the properties with the [EMIm]+ -ILs with the mixed water stable alkylcyanoborate anions points towards the potential of these fluorine-free borate anions, in general.
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Affiliation(s)
- Nils Schopper
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Institut für nachhaltige Chemie & Katalyse mit Bor (ICB), Am Hubland, 97074, Würzburg, Germany
| | - Johannes Landmann
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Institut für nachhaltige Chemie & Katalyse mit Bor (ICB), Am Hubland, 97074, Würzburg, Germany
| | - Jan A P Sprenger
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Institut für nachhaltige Chemie & Katalyse mit Bor (ICB), Am Hubland, 97074, Würzburg, Germany
| | - Ludwig Zapf
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Institut für nachhaltige Chemie & Katalyse mit Bor (ICB), Am Hubland, 97074, Würzburg, Germany
| | - Rüdiger Bertermann
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Institut für nachhaltige Chemie & Katalyse mit Bor (ICB), Am Hubland, 97074, Würzburg, Germany
| | - Nikolai V Ignat'ev
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Institut für nachhaltige Chemie & Katalyse mit Bor (ICB), Am Hubland, 97074, Würzburg, Germany
- Consultant, Merck Life Science KGaA, 64293, Darmstadt, Germany
| | - Maik Finze
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Institut für nachhaltige Chemie & Katalyse mit Bor (ICB), Am Hubland, 97074, Würzburg, Germany
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20
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Gruber N, Fernández-Canigia L, Kilimciler NB, Stipa P, Bisceglia JA, García MB, Gonzalez Maglio DH, Paz ML, Orelli LR. Amidinoquinoxaline N-oxides: synthesis and activity against anaerobic bacteria. RSC Adv 2023; 13:27391-27402. [PMID: 37711381 PMCID: PMC10498151 DOI: 10.1039/d3ra01184d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 08/20/2023] [Indexed: 09/16/2023] Open
Abstract
We present herein an in-depth study on the activity of amidinoquinoxaline N-oxides 1 against Gram-positive and Gram-negative anaerobic bacteria. Based on 5-phenyl-2,3-dihydropyrimidoquinoxaline N-oxide 1a, the selected structural variations included in our study comprise the substituents α- to the N-oxide function, the benzofused ring, substitution and quaternization of the amidine moiety, and the amidine ring size. Compounds 1 showed good to excellent antianaerobic activity, evaluated as the corresponding CIM50 and CIM90 values, and an antimicrobial spectrum similar to metronidazole. Six out of 13 compounds 1 had CIM90 values significantly lower than the reference drug. Among them, imidazoline derivatives 1i-l were the most active structures. Such compounds were synthesized by base-promoted ring closure of the corresponding amidines. The N-oxides under study showed no significant cytotoxicity against RAW 264.7 cells, with high selectivity indexes. Their calculated ADME properties indicate that the compounds are potentially good oral drug candidates. The antianaerobic activity correlated satisfactorily with the electron affinity of the compounds, suggesting that they may undergo bioreductive activation before exerting their antibacterial activity.
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Affiliation(s)
- Nadia Gruber
- Universidad de Buenos Aires, CONICET, Química Orgánica II, Departamento de Ciencias Químicas, Facultad de Farmacia y Bioquímica Junín 956 (1113) Buenos Aires Argentina
| | | | - Natalia B Kilimciler
- Universidad de Buenos Aires, CONICET, Química Orgánica II, Departamento de Ciencias Químicas, Facultad de Farmacia y Bioquímica Junín 956 (1113) Buenos Aires Argentina
| | - Pierluigi Stipa
- SIMAU Departament - Chemistry Division, Università Politecnica delle Marche Via Brecce Bianche 12 Ancona (I-60131) Italy
| | - Juan A Bisceglia
- Universidad de Buenos Aires, CONICET, Química Orgánica II, Departamento de Ciencias Químicas, Facultad de Farmacia y Bioquímica Junín 956 (1113) Buenos Aires Argentina
| | - María B García
- Universidad de Buenos Aires, CONICET, Química Orgánica II, Departamento de Ciencias Químicas, Facultad de Farmacia y Bioquímica Junín 956 (1113) Buenos Aires Argentina
| | - Daniel H Gonzalez Maglio
- Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral (IDEHU), Cátedra de Inmunología, Facultad de Farmacia y Bioquímica Junín 956 (1113) Buenos Aires Argentina
| | - Mariela L Paz
- Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral (IDEHU), Cátedra de Inmunología, Facultad de Farmacia y Bioquímica Junín 956 (1113) Buenos Aires Argentina
| | - Liliana R Orelli
- Universidad de Buenos Aires, CONICET, Química Orgánica II, Departamento de Ciencias Químicas, Facultad de Farmacia y Bioquímica Junín 956 (1113) Buenos Aires Argentina
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Radtke V, Priester D, Heering A, Müller C, Koslowski T, Leito I, Krossing I. The Unified Redox Scale for All Solvents: Consistency and Gibbs Transfer Energies of Electrolytes from their Constituent Single Ions. Chemistry 2023; 29:e202300609. [PMID: 37191477 DOI: 10.1002/chem.202300609] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/28/2023] [Accepted: 05/11/2023] [Indexed: 05/17/2023]
Abstract
We have devised the unified redox scale Eabs H2O , which is valid for all solvents. The necessary single ion Gibbs transfer energy between two different solvents, which only can be determined with extra-thermodynamic assumptions so far, must clearly satisfy two essential conditions: First, the sum of the independent cation and anion values must give the Gibbs transfer energy of the salt they form. The latter is an observable and measurable without extra-thermodynamic assumptions. Second, the values must be consistent for different solvent combinations. With this work, potentiometric measurements on silver ions and on chloride ions show that both conditions are fulfilled using a salt bridge filled with the ionic liquid [N2225 ][NTf2 ]: if compared to the values resulting from known pKL values, the silver and chloride single ion magnitudes combine within a uncertainty of 1.5 kJ mol-1 to the directly measurable transfer magnitudes of the salt AgCl from water to the solvents acetonitrile, propylene carbonate, dimethylformamide, ethanol, and methanol. The resulting values are used to further develop the consistent unified redox potential scale Eabs H2O that now allows to assess and compare redox potentials in and over six different solvents. We elaborate on its implications.
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Affiliation(s)
- Valentin Radtke
- Institut für Anorganische und, Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Denis Priester
- Institut für Anorganische und, Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Agnes Heering
- Institute of Chemistry, University of Tartu, Ravila 14a Str, 50411, Tartu, Estonia
| | - Carina Müller
- Institut für Anorganische und, Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Thorsten Koslowski
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Ivo Leito
- Institute of Chemistry, University of Tartu, Ravila 14a Str, 50411, Tartu, Estonia
| | - Ingo Krossing
- Institut für Anorganische und, Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstr. 21, 79104, Freiburg, Germany
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22
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Fujishima S, Sekimoto K, Takayama M. Identification of Negative Ion at m/z 20 Produced by Atmospheric Pressure Corona Discharge Ionization under Ambient Air. Mass Spectrom (Tokyo) 2023; 12:A0124. [PMID: 37360413 PMCID: PMC10288065 DOI: 10.5702/massspectrometry.a0124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 05/23/2023] [Indexed: 06/28/2023] Open
Abstract
The negative ion at m/z 20 observed at atmospheric pressure corona discharge ionization mass spectra has been identified by supplying the vapors of deuterium oxide (D2O) and H218O. From the mass shifts of the ion at m/z 20 observed with D2O and H218O, it was suggested that the chemical composition of the ion at m/z 20 is to be H4O. Further mass shift from m/z 20 to 22 was observed by supplying the vapor of perfluorokerocene, suggesting the chemical composition of H3F. The chemical compositions of the negative ions H4O- and H3F- were consistence with the dipole-bound complex states between hydrogen H2 and polar molecules such as H2O and hydrogen fluoride (HF) having dipole moments beyond a critical dipole moment of 1.625 D, theoretically proposed by Skurski and Simons. The ionic chemical compositions and structures of H4O- and H3F- obtained with density functional theory calculations implied that both dipole-bound complex H2O-…H2 and HF-…H2 can be formed by exothermic reactions by which H2 molecule is complexing with negative ions H2O- and HF-, respectively.
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Affiliation(s)
- Shiho Fujishima
- Graduate School in Nanobioscience, Yokohama City University, 22–2 Seto, Kanazawa-ku, Yokohama 236–0027, Japan
| | - Kanako Sekimoto
- Graduate School in Nanobioscience, Yokohama City University, 22–2 Seto, Kanazawa-ku, Yokohama 236–0027, Japan
| | - Mitsuo Takayama
- Graduate School in Nanobioscience, Yokohama City University, 22–2 Seto, Kanazawa-ku, Yokohama 236–0027, Japan
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Abstract
This Perspective attempts to shed light on developments in the theoretical and experimental study of molecular anions highlighting more recent workers in the field. The species I discuss include (i) valence-bound (singly and multiply charged) anions including atmospheric, catalytic, superhalogen, interfacial, and more; (ii) dipole- and correlation-bound anions including their role as doorways to other states and their appearance "in space", and (iii) metastable anions focusing on tools needed for their theoretical treatment. I also briefly discuss angular distributions of photodetached electrons and their growing utilization in experiments and theory. A recurring theme is the dependence of electron binding energies (EBEs) on the surrounding environment. Some anions that are nonexistent as isolated species evolve to be stable but with small EBEs when weakly solvated (e.g., as in a cluster or at an air-solvent interface). Others existing in isolation only as metastable species become stable when the underlying molecular framework contains one or more positively charged group (e.g., protonated side chains in a peptide) that generates a stabilizing Coulomb potential. On the other hand, a destabilizing Coulomb potential between/among negative sites in a multiply charged anion decreases the EBEs of each such site and generates a repulsive Coulomb barrier that can affect stability.
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Affiliation(s)
- Jack Simons
- Henry Eyring Center for Theoretical Chemistry, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
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24
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Neumark DM. Spectroscopy of Radicals, Clusters, and Transition States Using Slow Electron Velocity-Map Imaging of Cryogenically Cooled Anions. J Phys Chem A 2023; 127:4207-4223. [PMID: 37094039 DOI: 10.1021/acs.jpca.3c01537] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Slow electron velocity-map imaging of cryogenically cooled anions (cryo-SEVI) is a high-resolution variant of anion photoelectron spectroscopy that has been applied with considerable success over the years to the study of radicals, size-selected clusters, and transition states for unimolecular and bimolecular reactions. Cryo-SEVI retains the versatility of conventional anion photoelectron spectroscopy while offering sub-meV resolution, thereby enabling the resolution of vibrational structure in the photoelectron spectra of complex anions. This Feature Article describes recent experiments in our laboratory using cryo-SEVI, including a new research direction in which anions are vibrationally pre-excited with an infrared laser pulse prior to photodetachment.
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Affiliation(s)
- Daniel M Neumark
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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25
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Zhang R, Lu Y, Tang R, Ning C. Electron affinity of atomic scandium and yttrium and excited states of their negative ions. J Chem Phys 2023; 158:084303. [PMID: 36859075 DOI: 10.1063/5.0124882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The latest experimental electron affinity (EA) values of atomic scandium and yttrium were 0.189(20) and 0.308(12) eV as reported by Feigerle et al. in 1981. The measurement accuracy of these was far lower than that of other transition elements, and no conclusive result had been made on the excited states of their negative ions. In the current work, we report more accurate EA values of Sc and Y and the electronic structure of their negative ions using the slow-electron velocity-map imaging method. The EA values of Sc and Y are determined to be 0.179 378(22) and 0.311 29(22) eV, respectively. The ground state of Sc- is identified as 3d4s24p 1D2, and the ground state is 4d5s25p 1D2 for Y-. Furthermore, several excited states of Sc- and Y- are observed: Sc- (3D1) and Y- (3D1, 3D2, 3D3, 3F2, and 3F3), and their energy levels are determined to be 1131.8(28), 1210.0(13), 1362.3(30), 1467.7(26), 1747(16), and 1987(33) cm-1, respectively.
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Affiliation(s)
- Rui Zhang
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Yuzhu Lu
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Rulin Tang
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Chuangang Ning
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
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26
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Yan ST, Long ZC, Xu XL, Xu HG, Zheng WJ. Anion photoelectron spectroscopy and quantum chemical calculations of bimetallic niobium-aluminum clusters NbAl n-/0 ( n = 3-12): identification of a half-encapsulated symmetric structure for NbAl 12. Phys Chem Chem Phys 2023; 25:6498-6509. [PMID: 36786014 DOI: 10.1039/d2cp04978c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Bimetallic niobium-doped aluminum clusters, NbAln-/0 (n = 3-12), are investigated through a synergetic combination of size-selected anion photoelectron spectroscopy and theoretical calculations. It is found that the dominant structures of NbAln- anions with n = 3-8 can be described by gradually adding Al atoms to the NbAl3- core. Starting from n = 9, the lowest-energy geometric structures of NbAl9-12- transform into bilayer structures. In particular, NbAl12- has a C3v symmetric structure, which can be viewed as a NbAl6 regular hexagon over a bowl-shaped Al6 structure. More detailed analyses indicate that NbAl9 and NbAl12- possess unusual stability, which may be attributed to their closed-shell electron configurations with superatomic features.
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Affiliation(s)
- Shuai-Ting Yan
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhen-Chao Long
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xi-Ling Xu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong-Guang Xu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei-Jun Zheng
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
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27
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Endohedral group-14 clusters Au@X12 (X = Ge, Sn, Pb) and their anions: a first-principles study. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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28
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Chulanova EA, Radiush EA, Semenov NA, Hupf E, Irtegova IG, Kosenkova YS, Bagryanskaya IY, Shundrin LA, Beckmann J, Zibarev AV. Tuning Molecular Electron Affinities against Atomic Electronegativities by Spatial Expansion of a π-System. Chemphyschem 2023; 24:e202200876. [PMID: 36661050 DOI: 10.1002/cphc.202200876] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/11/2023] [Accepted: 01/19/2023] [Indexed: 01/21/2023]
Abstract
2,1,3-Benzochalcogenadiazoles C6 R4 N2 E (E/R; E=S, Se, Te; R=H, F, Cl, Br, I) and C6 H2 R2 N2 E (E/R'; E=S, Se, Te; R=Br, I) are 10π-electron hetarenes. By CV/EPR measurements, DFT calculations, and QTAIM and ELI-D analyses, it is shown that their molecular electron affinities (EAs) increase with decreasing Allen electronegativities and electron affinities of the E and non-hydrogen R (except Cl) atoms. DFT calculations for E/R+e⋅- →[E/R]⋅- electron capture reveal negative ΔG values numerically increasing with increasing atomic numbers of the E and R atoms; positive ΔS has a minor influence. It is suggested that the EA increase is caused by more effective charge/spin delocalization in the radical anions of heavier derivatives due to contributions from diffuse (a real-space expanded) p-AOs of the heavier E and R atoms; and that this counterintuitive effect might be of the general character.
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Affiliation(s)
- Elena A Chulanova
- Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russian Federation.,Current address: Institute for Applied Physics, University of Tübingen, 72076, Tübingen, Germany
| | - Ekaterina A Radiush
- Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russian Federation
| | - Nikolay A Semenov
- Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russian Federation
| | - Emanuel Hupf
- Institute for Inorganic Chemistry and Crystallography, University of Bremen, 28359, Bremen, Germany
| | - Irina G Irtegova
- Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russian Federation
| | - Yulia S Kosenkova
- Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russian Federation
| | - Irina Yu Bagryanskaya
- Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russian Federation
| | - Leonid A Shundrin
- Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russian Federation
| | - Jens Beckmann
- Institute for Inorganic Chemistry and Crystallography, University of Bremen, 28359, Bremen, Germany
| | - Andrey V Zibarev
- Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russian Federation
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29
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Workman KT, Firth RA, Gichuhi WK. From Benzonitrile to Dicyanobenzenes: The Effect of an Additional CN Group on the Thermochemistry and Negative Ion Photoelectron Spectra of Dicyanobenzene Radical Anions. J Phys Chem A 2023; 127:181-194. [PMID: 36592400 DOI: 10.1021/acs.jpca.2c07655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The negative ion photoelectron spectra of 1,2-dicyanobenzene (o-DCNB), 1,3-dicyanobenzene (m-DCNB), and 1,4-dicyanobenzene (p-DCNB) radical anions (DCNB·-), acquired through the computation of Frack-Condon (FC) factors, are presented. The FC calculations utilize harmonic frequencies and normal mode vectors derived from density functional theory at the B3LYP/aug-cc-pVQZ basis set. All the totally symmetric vibrational modes are treated with Duschinsky rotations to yield neutral DCNBs in their singlet (So) and lowest triplet (T1) states, following an electron removal from the doublet anionic ground state. For the So state, the adiabatic electron affinities (EAs) for o-, m-, and p-DCNB are 1.179, 1.103, and 1.348 eV. The EAs for the lowest T1 state in o-, m-, and p-DCNB are 4.151, 4.185, and 4.208 eV, resulting in an So-T1 energy difference (ΔEST) of 2.973, 3.082, and 2.860 eV. A vibrational analysis reveals evidence of FC activity involving ring distortion, C-N bending, and ring C═C stretching vibrational progressions in both the So and T1 states. With the detection of cyanonaphthalene (C10H7CN) and cyanoindene (C9H7CN) in the interstellar medium (ISM), our results highlight the extent to which replacing a single hydrogen on an aromatic molecule with a cyano group, C≡N, can alter the vibrational structure of the molecule/radical anion. As such, dicyano-polyaromatic hydrocarbons may be reasonably robust in the ISM, making it appealing to search for them in future interstellar detection missions.
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Affiliation(s)
- Kie T Workman
- Department of Chemistry, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee38505, United States.,Department of Chemical Engineering, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee38505, United States
| | - Rebecca A Firth
- Department of Chemistry, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee38505, United States
| | - Wilson K Gichuhi
- Department of Chemistry, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee38505, United States
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30
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Gimferrer M, Danés S, Vos E, Yildiz CB, Corral I, Jana A, Salvador P, Andrada DM. Reply to the 'Comment on "The oxidation state in low-valent beryllium and magnesium compounds"' by S. Pan and G. Frenking, Chem. Sci., 2022, 13, DOI: 10.1039/D2SC04231B. Chem Sci 2023; 14:384-392. [PMID: 36687341 PMCID: PMC9811512 DOI: 10.1039/d2sc05769g] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/21/2022] [Indexed: 12/23/2022] Open
Abstract
A recent article by Pan and Frenking challenges our assignment of the oxidation state of low valent group 2 compounds. With this reply, we show that our assignment of Be(+2) and Mg(+2) oxidation states in Be(cAACDip)2 and Mg(cAACDip)2 is fully consistent with our data. Some of the arguments exposed by Pan and Frenking were based on visual inspection of our figures, rather than a thorough numerical analysis. We discuss with numerical proof that some of the statements made by the authors concerning our reported data are erroneous. In addition, we provide further evidence that the criterion of the lowest orbital interaction energy in the energy decomposition analysis (EDA) method is unsuitable as a general tool to assess the valence state of the fragments. Other indicators based on natural orbitals for chemical valence (NOCV) deliver a more reliable bonding picture. We also emphasize the importance of using stable wavefunctions for any kind of analysis, including EDA.
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Affiliation(s)
- Martí Gimferrer
- Departament de Química, Institut de Química Computacional i Catàlisi, Universitat de Girona c/M. Aurelia Capmany 69 17003 Girona Spain
| | - Sergi Danés
- Departament de Química, Institut de Química Computacional i Catàlisi, Universitat de Girona c/M. Aurelia Capmany 69 17003 Girona Spain
- General and Inorganic Chemistry Department, University of Saarland Campus C4.1 66123 Saarbruecken Germany
| | - Eva Vos
- Departamento de Química, Universidad Autónoma de Madrid C/Francisco Tomás y Valiente 7 28049 Cantoblanco Madrid Spain
| | - Cem B Yildiz
- Department of Medicinal and Aromatic Plants, Aksaray University Hacilar Harmani 2 68100 Aksaray Turkey
| | - Inés Corral
- Departamento de Química, Universidad Autónoma de Madrid C/Francisco Tomás y Valiente 7 28049 Cantoblanco Madrid Spain
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad Gopanpally 500046 Hyderabad Telangana India
| | - Pedro Salvador
- Departament de Química, Institut de Química Computacional i Catàlisi, Universitat de Girona c/M. Aurelia Capmany 69 17003 Girona Spain
| | - Diego M Andrada
- General and Inorganic Chemistry Department, University of Saarland Campus C4.1 66123 Saarbruecken Germany
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31
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Investigation of superacidic behavior of hydrogenated FemFn (m = 1/2, n = 1–6/11) complexes and their abilities to form supersalts. Struct Chem 2022. [DOI: 10.1007/s11224-022-02099-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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32
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Zhang Y, Zhao W, Lu J, Zhang Y, Zhang H, Li X. First-Principles Studies of the Caged Germanium Clusters with Gold Doping and Their Adsorption on Graphdiyne Nanosheets. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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33
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Heindel JP, Hao H, LaCour RA, Head-Gordon T. Spontaneous Formation of Hydrogen Peroxide in Water Microdroplets. J Phys Chem Lett 2022; 13:10035-10041. [PMID: 36264238 DOI: 10.1021/acs.jpclett.2c01721] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
There is accumulating evidence that many chemical reactions are accelerated by several orders of magnitude in micrometer-sized aqueous or organic liquid droplets compared to their corresponding bulk liquid phase. However, the molecular origin of the enhanced rates remains unclear as in the case of spontaneous appearance of 1 μM hydrogen peroxide in water microdroplets. In this Letter, we consider the range of ionization energies and whether interfacial electric fields of a microdroplet can feasibly overcome the high energy step from hydroxide ions (OH-) to hydroxyl radicals (OH•) in a primary H2O2 mechanism. We find that the vertical ionization energies (VIEs) of partially solvated OH- ions are greatly lowered relative to the average VIE in the bulk liquid, unlike the case of the Cl- anion which shows no reduction in the VIEs regardless of solvation environment. Overall reduced hydrogen-bonding and undercoordination of OH- are structural features that are more readily present at the air-water interface, where the energy scale for ionization can be matched by statistically probable electric field values.
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Affiliation(s)
- Joseph P Heindel
- Kenneth S. Pitzer Theory Center and Department of Chemistry, University of California, Berkeley, California94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California94720, United States
| | - Hongxia Hao
- Kenneth S. Pitzer Theory Center and Department of Chemistry, University of California, Berkeley, California94720, United States
| | - R Allen LaCour
- Kenneth S. Pitzer Theory Center and Department of Chemistry, University of California, Berkeley, California94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California94720, United States
| | - Teresa Head-Gordon
- Kenneth S. Pitzer Theory Center and Department of Chemistry, University of California, Berkeley, California94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California94720, United States
- Departments of Bioengineering and Chemical and Biomolecular EngineeringUniversity of California, Berkeley, California94720, United States
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34
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Talaeizadeh M, Seyyed Ebrahimi SA, Khosravi P, Hamawandi B. Characterization of the Nano-Rod Arrays of Pyrite Thin Films Prepared by Aqueous Chemical Growth and a Subsequent Sulfurization. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6946. [PMID: 36234287 PMCID: PMC9570830 DOI: 10.3390/ma15196946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 09/25/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Pyrite is an earth-abundant and low-cost material with a specific collection of properties including a low band gap and high absorption coefficient of solar light. These properties make pyrite a good choice in a wide variety of applications such as catalysts, batteries, and photovoltaic devices. A thin film composed of vertically aligned pyrite nano-rods was processed via a hydration-condensation method followed by subsequent aging and sulfurization. In this process, no ionic salt was used which resulted in a lower cost process with a lower level of impurities. Field emission scanning electron microscopy, X-ray diffraction, and Raman spectroscopy analyses were used to characterize the thin films in different steps of the process. The major impurity of the final thin films was the marcasite phase according to the Raman analysis which could be minimized by lowering sulfurizing time to about 60 min. In addition, after structural, electrical, and optical characterization of thin films, these layers' performances in a photovoltaic device were also examined. After deposition of a thin aluminum layer, Schottky-type solar cells of pyrite formed which were then illuminated to measure their current-voltage characteristics. The results show that a combination of low-cost materials and a low-cost preparation method is applicable for building future solar cells.
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Affiliation(s)
- Mohammad Talaeizadeh
- Advanced Magnetic Materials Research Center, School of Metallurgy and Materials, College of Engineering, University of Tehran, Tehran 1417614411, Iran
| | - Seyyed Ali Seyyed Ebrahimi
- Advanced Magnetic Materials Research Center, School of Metallurgy and Materials, College of Engineering, University of Tehran, Tehran 1417614411, Iran
| | - Payam Khosravi
- Advanced Magnetic Materials Research Center, School of Metallurgy and Materials, College of Engineering, University of Tehran, Tehran 1417614411, Iran
- Department of Materials Engineering, Isfahan University of Technology, Isfahan 8415683111, Iran
| | - Bejan Hamawandi
- Department of Applied Physics, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
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35
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Luo QX, Cai YJ, Mao XL, Li YJ, Zhang CR, Liu X, Chen XR, Liang RP, Qiu JD. Tuned-Potential Covalent organic framework Electrochemiluminescence platform for lutetium analysis. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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36
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Electronic properties and chemical reactivity of biogenic amine neurotransmitters in gas and solution phase: A DFT study. COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2022.113841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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37
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Qin Z, Wang Q, Xu L, Lv W, Zheng X. Hydrogen bonds in mixed-solvent Au-(CH3OH)(H2O) complex: A joint experimental and theoretical study. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.139854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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38
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Yan ST, Xu XL, Xu HG, Zheng WJ. Anion Photoelectron Spectroscopy and Quantum Chemical Calculations of Bimetallic Oxide Clusters YCu 2O n-/0 ( n = 2-5). J Phys Chem A 2022; 126:6067-6079. [PMID: 36043908 DOI: 10.1021/acs.jpca.2c03968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structural and electronic properties of bimetallic oxide clusters, YCu2On- and YCu2On (n = 2-5), are investigated using anion photoelectron spectroscopy and density functional theory calculations. The experimental vertical detachment energies of YCu2O2-, YCu2O3-, YCu2O4-, and YCu2O5- were measured to be 1.59, 1.76, 3.85, and 3.78 eV, respectively. Vibrationally resolved photoelectron spectra have been obtained for YCu2O2-, with a spacing of 726 ± 80 cm-1 assigned to the Y-O stretching vibrational mode. It is found that YCu2O2- and YCu2O2 have C2v symmetric planar five-membered ring structures. YCu2O3- and YCu2O3 have C2v symmetric planar six-membered ring structures. The most stable structure of YCu2O4- is a quasi-planar structure which can be viewed as one O atom interacting with the Y atom of the YCu2O3 six-membered ring, while the most stable structure of YCu2O4 is a planar seven-membered ring. YCu2O5- and YCu2O5 have nonplanar structures, which can be viewed as an O2 unit interacting with the Y atom of the YCu2O3 six-membered ring. In YCu2O3,4,5-/0, the Y-O and Cu-O bonds are dominant, while the Y-Cu and Cu-Cu interactions are weak.
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Affiliation(s)
- Shuai-Ting Yan
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xi-Ling Xu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong-Guang Xu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei-Jun Zheng
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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39
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Shi MX, Tao ML, Sun K, Li Z, Yang DX, Wang JZ. Structural transition and interconversion between the 2D self-assembled structures of pentacene. Phys Chem Chem Phys 2022; 24:17744-17750. [PMID: 35843214 DOI: 10.1039/d2cp01750d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The 2D self-assemblies and structural transitions of pentacene on a Cd(0001) surface have been investigated with low temperature scanning tunneling microscopy (STM). With increasing coverage, pentacene molecules show a structural evolution from the initial disordered gas-like phase through the porous network phase to the herringbone phase, and finally to the brickwall phase at the full monolayer. In particular, orientational frustration and cooperative rotation of pentacene molecules take place in the herringbone phase. Furthermore, successive STM scanning leads to structural interconversions between the porous network phase, herringbone phase, and brickwall phase, indicating the metastability of the 2D assembled structures of pentacene on Cd(0001). These structural transitions and interconversion can be attributed to the interplay between the repulsive electrostatic forces resulting from the charge transfer from the substrate to pentacene and the attractive effects originating from dipole-dipole interactions and intermolecular van der Waals forces.
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Affiliation(s)
- Ming-Xia Shi
- School of Physical Science and Technology, Southwest University, Chongqing, 400715, China.
| | - Min-Long Tao
- School of Physical Science and Technology, Southwest University, Chongqing, 400715, China.
| | - Kai Sun
- School of Physical Science and Technology, Southwest University, Chongqing, 400715, China.
| | - Zuo Li
- School of Physical Science and Technology, Southwest University, Chongqing, 400715, China.
| | - Da-Xiao Yang
- School of Physical Science and Technology, Southwest University, Chongqing, 400715, China.
| | - Jun-Zhong Wang
- School of Physical Science and Technology, Southwest University, Chongqing, 400715, China.
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40
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Zhang T, Zhang C, Ma X, Quan H. Substitution Effects on the Reactivity and Thermostability of Five-Membered Ring Fluorides. ACS OMEGA 2022; 7:25476-25490. [PMID: 35910138 PMCID: PMC9330182 DOI: 10.1021/acsomega.2c02461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Recently, five-membered ring fluorides (c-C5Fs) have been significantly desirable in green chlorofluorocarbon substitutes due to their practically flexible application in various fields and environmental friendliness. Detailed knowledge regarding different substitution effects on their environmental properties and thermal stability is very limited due to their high-cost experiments. Here, comprehensive density functional theory and ab initio molecular dynamics calculations were performed to explore the relative electrophilic and nucleophilic reactivity and thermostability of c-C5F chemicals. The electronic properties induced by substitution effects of c-C5Fs were first explored. The environmental friendliness of c-C5Fs including 1,1,2,2,3,3-hexafluorocyclopentane (F6A), 1,1,2,2,3,3,4-heptafluorocyclopentane (F7A), cis-1,1,2,2,3,3,4,5-octafluorocyclopentane (F8A), 3,3,4,4,5,5-hexafluorocyclopentene (F6E), 1,3,3,4,4,5,5-heptafluorocyclopentene (F7E), octafluorocyclopentene (F8E), 1-chloro-3,3,4,4,5,5-hexafluorocyclopent-1-ene (F6-1), and 1-chloro-2,3,3,4,4,5,5-heptafluorocyclopent-1-ene (F7-1) was validly confirmed. Besides, their thermal stabilities at 600 K temperature were concluded due to their flexible carbon skeletons, where both in-plane stability and slight aromaticity of F6E were in peculiar found to contribute substantially. We also would like to stress the future application of F6-1 due to its significant out-plane stability. This study may pave the way for the development of chlorofluorocarbon substitutes.
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Affiliation(s)
- Tongyun Zhang
- School
of Chemical Engineering, Northwest University, 229 Taibai North Road, Xi’an, Shaanxi 710069, China
| | - Chengping Zhang
- School
of Chemistry and Chemical Engineering, Beijing
Institute of Technology, 5 South Zhongguancun Street, Beijing 100081, China
| | - Xiaoxun Ma
- School
of Chemical Engineering, Northwest University, 229 Taibai North Road, Xi’an, Shaanxi 710069, China
| | - Hengdao Quan
- School
of Chemistry and Chemical Engineering, Beijing
Institute of Technology, 5 South Zhongguancun Street, Beijing 100081, China
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41
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Abstract
A few months before the COVID-19 pandemic, Pierre Vogel and Kendall N. Houk published with a new textbook Wiley-VCH, “Organic Chemistry: Theory, Reactivity, and Mechanisms in Modern Synthesis”, with a foreword from the late Roberts H. Grubbs. The book demonstrates how catalytic processes dominate all fields of modern organic chemistry and synthesis, and how invention combines thermodynamics, kinetics, spectroscopy, quantum mechanics, and thermochemical data libraries. Here, the authors present a few case studies that should be of interest to teachers, practitioners of organic and organometallic chemistry, and the engineers of molecules. The Vogel–Houk book is both textbook and reference manual; it provides a modern way to think about chemical reactivity and a powerful toolbox to inventors of new reactions and new procedures.
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42
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Curtolo F, Arantes GM. Molecular properties and tautomeric equilibria of isolated flavins. J Comput Chem 2022; 43:1561-1572. [PMID: 35778728 DOI: 10.1002/jcc.26957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/09/2022] [Indexed: 11/05/2022]
Abstract
Flavins are employed as redox cofactors and chromophores in a plethora of flavoenzymes. Their versatility is an outcome of intrinsic molecular properties of the isoalloxazine ring modulated by the protein scaffold and surrounding solvent. Thus, an investigation of isolated flavins with high-level electronic-structure methods and with error assessment of the calculated properties will contribute to building better models of flavin reactivity. Here, we benchmarked ground-state properties such as electron affinity, gas-phase basicity, dipole moment, torsion energy, and tautomer stability for lumiflavins in all biologically relevant oxidation and charge states. Overall, multiconfigurational effects are small and chemical accuracy is achieved by coupled-cluster treatments of energetic properties. Augmented basis sets and extrapolations to the complete basis-set limit are necessary for consistent agreement with experimental energetics. Among DFT functionals tested, M06-2X shows the best performance for most properties, except gas-phase basicity, in which M06 and CAM-B3LYP perform better. Moreover, dipole moments of radical flavins show large deviations for all functionals studied. Tautomers with noncanonical protonation states are significantly populated at normal temperatures, adding to the complexity of modeling flavins. These results will guide future computational studies of flavoproteins and flavin chemistry by indicating the limitations of electronic-structure methodologies and the contributions of multiple tautomeric states.
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Affiliation(s)
- Felipe Curtolo
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Guilherme M Arantes
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
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43
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Hariri M, Jafari MT, Jazan E. Investigation of different alcoholic modifiers for the separation and determination of two isomers of dinitrotoluene (2,4 and 2,6) by ion mobility spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2022; 36:e9274. [PMID: 35178790 DOI: 10.1002/rcm.9274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 12/04/2021] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
Some alcoholic modifier gases were applied to separate isomer peaks in ion mobility spectrometry (IMS). Different mechanisms have been investigated on the separation, such as collision cross-section and analyte-modifier cluster formation. In this regard, some parameters that affected the cluster formation, such as dipole moment, electron affinity, the position of functional groups, and the modifier structure, were evaluated. On the other hand, some effective experimental parameters, including cell temperature and the flow rates of the drift and modifier gases, were also optimized. The combination of dispersive liquid-liquid microextraction with thin-film evaporation (DLLME-TFE) was used as a sample preparation method for the extraction of 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT) isomers (as the target analytes). Isobutanol was selected as the alcoholic modifier to separate the ion molecular peaks of these isomers. The limit of detection and the limit of quantification obtained were 15 and 50 μg L-1 , and the linear dynamic range (50-700 μg L-1 ) with coefficient of determination of 0.9941 and 0.9914 were obtained for 2,4-DNT and 2,6-DNT, respectively. The intra- and inter-day relative standard deviations were obtained between 3% and 5%. For validation of the method, determination of the isomers was accomplished for a red wastewater field sample, resulting in relative recovery values of about 96%.
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Affiliation(s)
- Mohammad Hariri
- Department of Chemistry, Isfahan University of Technology, Isfahan, Iran
| | - Mohammad T Jafari
- Department of Chemistry, Isfahan University of Technology, Isfahan, Iran
| | - Elham Jazan
- Department of Chemistry, Shahreza Branch, Islamic Azad University, Isfahan, Iran
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44
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Wang H, Wang Y, Li H, Hu Y, Fan Q, King RB, Schaefer HF. Adiabatic Electron Detachment Energies, Reaction Barriers, Chemical Balance, and Ligand Effects on the Nucleophilicities of Metal Carbonyl Monoanions. Organometallics 2022. [DOI: 10.1021/acs.organomet.1c00716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Huijie Wang
- School of Science, Key Laboratory of High Performance Scientific Computation, Xihua University, Chengdu 610039, China
| | - Yanshu Wang
- School of Science, Key Laboratory of High Performance Scientific Computation, Xihua University, Chengdu 610039, China
| | - Huidong Li
- School of Science, Key Laboratory of High Performance Scientific Computation, Xihua University, Chengdu 610039, China
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Yucheng Hu
- School of Science, Key Laboratory of High Performance Scientific Computation, Xihua University, Chengdu 610039, China
| | - Qunchao Fan
- School of Science, Key Laboratory of High Performance Scientific Computation, Xihua University, Chengdu 610039, China
| | - R. Bruce King
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
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45
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Oh D, Lee S, Kim J. Theoretical study on molecular properties of
SbX
n
(X = F and Cl,
n
= 1–5) and
SbX
n
−
(X = F and Cl,
n
= 1–6) including
spin–orbit
coupling. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Dakyeung Oh
- Department of Chemistry The Catholic University of Korea Bucheon Republic of Korea
| | - Seongjae Lee
- Department of Chemistry The Catholic University of Korea Bucheon Republic of Korea
| | - Joonghan Kim
- Department of Chemistry The Catholic University of Korea Bucheon Republic of Korea
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46
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Poutsma JC, Moeller W, Poutsma JL, Sweeny BC, Ard SG, Viggiano AA, Shuman NS. Structures and Electron Affinities of Aluminum Hydride Clusters Al nH ( n = 3-13). J Phys Chem A 2022; 126:1648-1659. [PMID: 35245062 DOI: 10.1021/acs.jpca.1c10431] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Low-energy structures and electron affinities (EAs) for aluminum hydride clusters AlnH (n = 3-13) have been calculated using ab initio and density functional calculations. Geometries were optimized at the PBE0/def-2-TZVPP level of theory, which has been shown to match the currently accepted lowest-energy structures for the all-aluminum clusters Aln and their anions. Neutral hydride clusters with n = 4, 7, and 9-12 are predicted to adopt terminal structures with the hydrogen atom bound to only one aluminum atom and with only minor alterations of the aluminum atom arrangement from that of the all-aluminum cluster. Clusters with n = 3 and 13 are predicted to adopt "face-centered" geometries, and the n = 6 cluster is predicted to prefer an isomer with the hydrogen atom bridging two aluminum atoms, also with little or no distortion to the aluminum atom arrangement from the all-aluminum cluster. Addition of a hydrogen atom to clusters with n = 5 and 8 is predicted to distort the aluminum atom arrangement significantly from that of the corresponding all-aluminum cluster. In the anionic clusters, terminal clusters are preferred for all cluster sizes except for n = 6 that prefers a face-centered arrangement. Minor distortions in the aluminum scaffolding for Al11 and Al12 were found, while all other anionic clusters adopt structures with little or no deviation in the aluminum atom arrangement from the corresponding all-aluminum cluster. Raw adiabatic electron affinities were computed using CCSD(T)/aug-cc-pVTZ single-point energies for the anionic and neutral hydride clusters at their respective DFT geometries. Isodesmic electron affinities for the hydride clusters were computed relative to their all-aluminum counterparts and show an even-odd alternation with cluster size. Derived EAs alternate in magnitude between even- and odd-numbered clusters, with the even-numbered clusters having relatively larger EAs.
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Affiliation(s)
- John C Poutsma
- Department of Chemistry, The College of William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - William Moeller
- Department of Chemistry, The College of William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - Jennifer L Poutsma
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia 23529, United States
| | - Brendan C Sweeny
- Institute for Scientific Research, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Shaun G Ard
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, Albuquerque, New Mexico 87117, United States
| | - Albert A Viggiano
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, Albuquerque, New Mexico 87117, United States
| | - Nicholas S Shuman
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, Albuquerque, New Mexico 87117, United States
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47
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Lozano AI, Kumar S, Kerkeni B, García G, Limão-Vieira P. Methanol Negative Ion Fragmentation Probed in Electron Transfer Experiments. J Phys Chem A 2022; 126:1076-1084. [PMID: 35143199 DOI: 10.1021/acs.jpca.1c07588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this contribution, we report a novel comprehensive investigation on negative ion formation from electron transfer processes mediated by neutral potassium atom collisions with neutral methanol molecules employing experimental and theoretical methodologies. Methanol collision-induced fragmentation yielding anion formation has been obtained by time-of-flight mass spectrometry in the wide energy range of 19 to 275 eV in the lab frame. The negative ions formed in such a collision process have been assigned to CH3O-, OH-, and O-, with a strong energy dependence especially at lower collision energies. The most intense fragment anions in the whole energy range investigated have been assigned to OH- and CH3O-. Additionally, the potassium cation energy loss spectrum in the forward scattering direction at 205 eV impact energy has revealed several features, where the two main electronic states accessible during the collision events have vertical electron affinities of -8.26 ± 0.20 and -10.36 ± 0.2 eV. Quantum chemical calculations have been performed for the lowest-lying unoccupied molecular orbitals of methanol in the presence of a potassium atom, lending strong support to the experimental findings.
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Affiliation(s)
- Ana Isabel Lozano
- Atomic and Molecular Collisions Laboratory, Centro de Física e Investigação Tecnológica, Department of Physics, Universidade NOVA de Lisboa, Caparica 2829-516, Portugal.,Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas (CSIC), Serrano 113-bis, Madrid 28006, Spain
| | - Sarvesh Kumar
- Atomic and Molecular Collisions Laboratory, Centro de Física e Investigação Tecnológica, Department of Physics, Universidade NOVA de Lisboa, Caparica 2829-516, Portugal
| | - Boutheïna Kerkeni
- Institut Supérieur des Arts Multimédia de la Manouba, Université de la Manouba, La Manouba 2010, Tunisia.,Département de Physique, Laboratoire de recherche: Physique de la matière condensée, Faculté des Sciences de Tunis, Université de Tunis el Manar, Tunis 2092, Tunisia
| | - Gustavo García
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas (CSIC), Serrano 113-bis, Madrid 28006, Spain
| | - Paulo Limão-Vieira
- Atomic and Molecular Collisions Laboratory, Centro de Física e Investigação Tecnológica, Department of Physics, Universidade NOVA de Lisboa, Caparica 2829-516, Portugal
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48
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Gruber E, Kollotzek S, Bergmeister S, Zappa F, Ončák M, Scheier P, Echt O. Phenanthrene: establishing lower and upper bounds to the binding energy of a very weakly bound anion. Phys Chem Chem Phys 2022; 24:5138-5143. [PMID: 35156966 PMCID: PMC8865840 DOI: 10.1039/d1cp04755h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/21/2021] [Indexed: 01/08/2023]
Abstract
Quite a few molecules do not form stable anions that survive the time needed for their detection; their electron affinities (EA) are either very small or negative. How does one measure the EA if the anion cannot be observed? Or, at least, can one establish lower and upper bounds to their EA? We propose two approaches that provide lower and upper bounds. We choose the phenanthrene (Ph) molecule whose EA is controversial. Through competition between helium evaporation and electron detachment in HenPh- clusters, formed in helium nanodroplets, we estimate the lower bound of the vertical detachment energy (VDE) of Ph- as about -3 meV. In the second step, Ph is complexed with calcium whose electron affinity is just 24.55 meV. When CaPh- ions are collided with a thermal gas of argon, one observes Ca- product ions but no Ph-, suggesting that the EA of Ph is below that of Ca.
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Affiliation(s)
- Elisabeth Gruber
- Institut für Ionenphysik und Angewandte Physik Universität Innsbruck Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Siegfried Kollotzek
- Institut für Ionenphysik und Angewandte Physik Universität Innsbruck Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Stefan Bergmeister
- Institut für Ionenphysik und Angewandte Physik Universität Innsbruck Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Fabio Zappa
- Institut für Ionenphysik und Angewandte Physik Universität Innsbruck Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik Universität Innsbruck Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Paul Scheier
- Institut für Ionenphysik und Angewandte Physik Universität Innsbruck Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Olof Echt
- Institut für Ionenphysik und Angewandte Physik Universität Innsbruck Technikerstraße 25, 6020 Innsbruck, Austria.
- Department of Physics University of New Hampshire Durham, NH 03824, USA.
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49
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Tan LP, Die D, Zheng BX. Growth mechanism, electronic properties and spectra of aluminum clusters. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 267:120545. [PMID: 34739894 DOI: 10.1016/j.saa.2021.120545] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/29/2021] [Accepted: 10/24/2021] [Indexed: 06/13/2023]
Abstract
Density functional theory (DFT) and particle swarm optimization (PSO) have been applied to study the growth behavior, electronic properties and spectra of neutral, anionic and cationic aluminum clusters with 3-20 atoms. Many isomers have been obtained through a comprehensive structural search. The results indicate that the ground state structures of neutral and anionic aluminum clusters follow an identical periodic growth law. When the number of atoms is 6-11 and 13-18, Al atoms in these clusters grow around an octahedral cluster nucleus and an icosahedral cluster nucleus, respectively. For Aln+ (n ≤ 14 and n ≠ 7) clusters, the most stable structure is different from that of Aln or Aln-clusters. When n > 14, the ground state structure of Aln+ clusters is similar to that of Aln or Aln-clusters. The electronic properties of aluminum clusters have been analyzed by the averaged binding energy, second-order difference of energy, energy gap and dissociation energy. It is found that the Al7+ and Al13- clusters have very high stability and a large energy gap and can be regarded as two superatoms. The aluminum cluster with 18 or 40 valence electrons are the least likely to lose an electron. The dissociation behavior of Aln+ clusters caused by collision is reasonably explained by means of the dissociation energy. The optical absorption spectra of neutral aluminum clusters have been simulated by using the time-dependent density functional theory. The ground states of anionic aluminum clusters have been determined by comparing theoretical photoelectron spectra (PES) with experimental findings. Infrared and Raman spectra of cationic aluminum clusters have been forecasted and can assist in identifying the most stable structure in future experiments.
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Affiliation(s)
- Li-Ping Tan
- School of Science, Xihua University, Chengdu 610039, China
| | - Dong Die
- School of Science, Xihua University, Chengdu 610039, China.
| | - Ben-Xia Zheng
- School of Science, Xihua University, Chengdu 610039, China
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50
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Yan ST, Xu HG, Xu XL, Zheng WJ. Anion photoelectron spectroscopy and theoretical calculations of Cu4On−/0 (n = 1–4): Identification of stable quasi-square structure for Cu4O4−. J Chem Phys 2022; 156:054304. [DOI: 10.1063/5.0078415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Shuai-Ting Yan
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong-Guang Xu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xi-Ling Xu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei-Jun Zheng
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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