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Lu T. Theoretical Prediction and Comprehensive Characterization of an All-Nitrogenatomic Ring, Cyclo[18]Nitrogen (N 18). Chemphyschem 2024; 25:e202400377. [PMID: 38722092 DOI: 10.1002/cphc.202400377] [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: 04/01/2024] [Revised: 05/07/2024] [Indexed: 06/20/2024]
Abstract
The cyclic molecule cyclo[18]carbon composed of 18 carbon atoms has been observed in condensed phase experiment in recent years and has attracted great attention. Through state-of-art quantum chemistry calculation, this study found that 18 nitrogen atoms can also form a macrocyclic system, cyclo[18]nitrogen (N18), though its lifetime is very short at room temperature and can only exist for a relatively long time at very low temperatures. We comprehensively theoretically studied properties of N18, including geometric configurations, thermal decomposition mechanism and rate, molecular dynamics behavior, energetic properties, vibrational and electronic spectra. We also discussed in depth the electronic structure of N18, including nature of the N-N bonds, lone-pairs, charge distribution characteristics, electronic delocalization, and aromaticity. This work is not only the first exploration of the macrocyclic N18 molecule, but also the first time to systematically examine a very long-chain substance fully composed of nitrogen atoms in isolated state.
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Affiliation(s)
- Tian Lu
- Beijing Kein Research Center for Natural Sciences, Beijing, 100024, P. R. China
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2
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Gong K, Xu F, Zhao Z, Li W, Liu D, Zhou X, Wang L. Theoretical investigation on the functional group modulation of UV-Vis absorption profiles of triphenylamine derivatives. Phys Chem Chem Phys 2023; 25:22002-22010. [PMID: 37555282 DOI: 10.1039/d3cp01630g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
Understanding the functional group modulation of electronic structure and excitation is pivotal to the design of organic small molecules (OSMs) for photoelectric applications. In this study, we employed density functional theory (DFT) and time-dependent DFT (TDDFT) calculations to explore the unique absorption character of four triphenylamine photosensitizers. The various conformations were investigated given the multiple single bonds in the compounds, and the resemblance in the electronic structure of different conformations is affirmed because the coplanarity and consequent long-range conjugation is maintained regardless of the orientation of the flexible blocks. Six functionals were evaluated, and MN15 was found to successfully reproduce the intense secondary absorption peak for the double 3,4-ethylenedioxythiophene (EDOT) modified sensitizer over B3LYP, PBE0, M062X, CAM-B3LYP, and ωB97XD. The introduction of EDOT gives rise to a new excited state S4, which is a local excitation constrained in the EDOT substituent triphenylamine block. This new excited state S4, in combination with inherent S2 and S3 derived from prototype molecule TPA-Pyc, jointly contributes to the hump of the secondary absorption peak of ETE-Pyc and finally affects the light-harvesting ability of the dye-sensitized TiO2 photoanode. The current findings provide guidance toward the rational design of OSMs with good light-harvest ability.
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Affiliation(s)
- Kun Gong
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, P. R. China.
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, P. R. China
- Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin, 300350, P. R. China
| | - Fang Xu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, P. R. China.
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, P. R. China
- Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin, 300350, P. R. China
| | - Zhen Zhao
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, P. R. China.
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, P. R. China
- Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin, 300350, P. R. China
| | - Wei Li
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, P. R. China.
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, P. R. China
- Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin, 300350, P. R. China
| | - Dongzhi Liu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, P. R. China.
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, P. R. China
- Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin, 300350, P. R. China
| | - Xueqin Zhou
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, P. R. China.
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, P. R. China
- Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin, 300350, P. R. China
| | - Lichang Wang
- Department of Chemistry and Biochemistry; and the Materials Technology Center, Southern Illinois University, Carbondale, IL 62901, USA.
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Malik R, Bu Y. Magnetic coupling modulation in meta-nitroxide-functionalized isoalloxazine magnets with redox-active units as efficient side-modulators. Phys Chem Chem Phys 2023. [PMID: 37335558 DOI: 10.1039/d3cp01611k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
Magnetic conversion can be accomplished in a variety of ways, as organic molecules with switchable magnetic characteristics offer numerous technological applications. It is crucial to find magnetism-switchable systems because, in the field of organic magnetic materials, the redox-induced magnetic reversal is very simple to achieve and shows significant applications. Herein, we computationally design isoalloxazine-based diradicals through oxidizing N10 and adding a nitroxide to C8 as the spin source (i.e. 8-nitroxide-isoalloxazine 10-oxide, an m-phenylene-like nitroxide diradical expanded with a redox unit as a side-modulator) and its N1/N5-hydrogenated/protonated diradical derivatives and introducing substituents (-OH, -NH2, and -NO2) to C6. We demonstrate that the basically modified structure exhibits ferromagnetic (FM) characteristics with a magnetic coupling constant (J) of 561.3 cm-1 calculated at the B3LYP/6-311+G(d,p) level, obeying the meta-phenylene-mediated diradical character, and dihydrogenation can lead to an AFM diradical with considerably large J (-976.1 cm-1). Surprisingly, protonation at N1 or N5 can lead to distinctly different magnetic variations (561.3 → -1602.9 cm-1 at N1 versus 561.3 → 379.1 cm-1 at N5). Analyses indicate that small singlet-triplet energy gaps and small energy gaps between the highest occupied and lowest unoccupied molecular orbitals (HOMO, LUMO) of the closed shell singlet state are the key features of these isoalloxazine diradicals, and aromaticity variations, significant spin delocalization from the π-conjugated structure and spin polarization from the non-Kekule structure induced by modification are responsible for the magnetic conversion. Furthermore, the spin alternation rule, the singly occupied molecular orbital (SOMO) effect, and the SOMO-SOMO energy splitting of the triplet state are used to analyze these distinct variations. This work provides a novel understanding of the structures and characteristics of modified isoalloxazine diradicals, as well as essential details for the intricate design and characterization of new isoalloxazine-based potential organic magnetic switches.
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Affiliation(s)
- Rabia Malik
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, People's Republic of China.
| | - Yuxiang Bu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, People's Republic of China.
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Maley SM, Lief GR, Buck RM, Sydora OL, Yang Q, Bischof SM, Ess DH. Density functional theory and CCSD(T) evaluation of ionization potentials, redox potentials, and bond energies related to zirconocene polymerization catalysts. J Comput Chem 2023; 44:506-515. [PMID: 35662063 DOI: 10.1002/jcc.26890] [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: 12/09/2021] [Revised: 03/28/2022] [Accepted: 04/22/2022] [Indexed: 01/07/2023]
Abstract
Quantum-mechanical-based computational design of molecular catalysts requires accurate and fast electronic structure calculations to determine and predict properties of transition-metal complexes. For Zr-based molecular complexes related to polyethylene catalysis, previous evaluation of density functional theory (DFT) and wavefunction methods only examined oxides and halides or select reaction barrier heights. In this work, we evaluate the performance of DFT against experimental redox potentials and bond dissociation enthalpies (BDEs) for zirconocene complexes directly relevant to ethylene polymerization catalysis. We also examined the ability of DFT to compute the fourth atomic ionization potential of zirconium and the effect the basis set selection has on the ionization potential computed with CCSD(T). Generally, the atomic ionization potential and redox potentials are very well reproduced by DFT, but we discovered relatively large deviations of DFT-calculated BDEs compared to experiment. However, evaluation of BDEs with CCSD(T) suggests that experimental values should be revisited, and our CCSD(T) values should be taken as most accurate.
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Affiliation(s)
- Steven M Maley
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, USA
| | - Graham R Lief
- Research and Technology, Chevron Phillips Chemical Company, Bartlesville, Oklahoma, USA
| | - Richard M Buck
- Research and Technology, Chevron Phillips Chemical Company, Bartlesville, Oklahoma, USA
| | - Orson L Sydora
- Research and Technology, Chevron Phillips Chemical Company, Kingwood, Texas, USA
| | - Qing Yang
- Research and Technology, Chevron Phillips Chemical Company, Bartlesville, Oklahoma, USA
| | - Steven M Bischof
- Research and Technology, Chevron Phillips Chemical Company, Kingwood, Texas, USA
| | - Daniel H Ess
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, USA
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A Statistically Supported Antioxidant Activity DFT Benchmark-The Effects of Hartree-Fock Exchange and Basis Set Selection on Accuracy and Resources Uptake. Molecules 2021; 26:molecules26165058. [PMID: 34443645 PMCID: PMC8398206 DOI: 10.3390/molecules26165058] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 08/10/2021] [Accepted: 08/19/2021] [Indexed: 11/17/2022] Open
Abstract
Polyphenolic compounds are now widely studied using computational chemistry approaches, the most popular of which is Density Functional Theory. To ease this process, it is critical to identify the optimal level of theory in terms of both accuracy and resource usage—a challenge we tackle in this study. Eleven DFT functionals with varied Hartree–Fock exchange values, both global and range-separated hybrids, were combined with 14 differently augmented basis sets to calculate the reactivity indices of caffeic acid, a phenolic acid representative, and compare them to experimental data or a high-level of theory outcome. Aside from the main course, a validation of the widely used Janak’s theorem in the establishment of vertical ionization potential and vertical electron affinity was evaluated. To investigate what influences the values of the properties under consideration, linear regression models were developed and thoroughly discussed. The results were utilized to compute the scores, which let us determine the best and worst combinations and make broad suggestions on the final option. The study demonstrates that M06–2X/6–311G(d,p) is the best fit for such research, and, curiously, it is not necessarily essential to include a diffuse function to produce satisfactory results.
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Boruah A, Borpuzari MP, Kar R. Performance of Range Separated Density Functional in Solvent Continuum: Tuning Long‐range Hartree–Fock Exchange for Improved Orbital Energies. J Comput Chem 2019; 41:295-304. [DOI: 10.1002/jcc.26101] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/10/2019] [Accepted: 10/16/2019] [Indexed: 11/05/2022]
Affiliation(s)
- Abhijit Boruah
- Department of ChemistryDibrugarh University Dibrugarh Assam 786004 India
| | | | - Rahul Kar
- Department of ChemistryDibrugarh University Dibrugarh Assam 786004 India
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Chen D, Bu Y. Rational magnetic modification of N,N-dioxidized pyrazine ring expanded adenine and thymine: a diradical character induced by base pairing and double protonation. Phys Chem Chem Phys 2019; 21:20095-20106. [PMID: 31482894 DOI: 10.1039/c9cp03234g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rational modification of biomolecules especially DNA base pairs for the theoretical design of molecular magnets has attracted extensive interest. In this work, we report a modification strategy for adenine/thymine-based magnets through introducing a N,N-dioxidized pyrazine ring to either adenine or thymine to form ring-expanded bases (noA/noT) based on their experimentally synthesized derivatives. Further functionalization is conducted by double protonation and pairing with a normal complementary base (nohA-T/nohT-A), respectively. The diversity of protonation sites in noA generates totally six nohA-Ts, together with nohT-A forming seven two-step modified topic base pairs. DFT calculations are performed to characterize the magnetic properties and the diradical character, which indicate three diamagnetic (DM) nohA-Ts and three antiferromagnetic (AFM) nohA-Ts with extremely large magnetic coupling constants J ranging from -1279.7 to -2807.4 cm-1, while a relatively mild AFM nohT-A with a J of -194.6 cm-1. The electron separation effect induced by attraction of positive charges originating from protonation is proposed to explain the diradicalization, which is different from the traditional radical-coupler-radical coupling mode. In addition, atomic natural charges and spin densities, and H-bond and molecular orbital analyses are further discussed for verification and deep understanding of the observed unique phenomena. It should be noted that our designed seven topic base pairs have excellent characters including a good synthetic basis, a large scope of the |J| values, and the AFM-DM magnetic conversion or AFM strength modulation controlled by protonation/deprotonation, prototropic tautomerization, base pairing/dissociation, single proton transfer, and even the applied electric field. All these indicate the promising applications in the field of magnetic information storage or switch control. This work highlights the magnetic modification schemes and possible modulation methods of double positive charge doped DNA base pairs by utilizing their potential spin coupling modes.
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Affiliation(s)
- Dongxiao Chen
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People's Republic of China.
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Vikramaditya T, Lin S. Limitations of Global Hybrids in Predicting the Geometries and Torsional Energy Barriers of Dimeric Systems and the Role of Hartree Fock and DFT Exchange. J Comput Chem 2019; 40:2810-2818. [DOI: 10.1002/jcc.26056] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/25/2019] [Accepted: 08/09/2019] [Indexed: 11/07/2022]
Affiliation(s)
- Talapunur Vikramaditya
- Computational Molecular Engineering Lab, Department of Chemical Engineering, National Taiwan University Taipei 10617 Taiwan
| | - Shiang‐Tai Lin
- Computational Molecular Engineering Lab, Department of Chemical Engineering, National Taiwan University Taipei 10617 Taiwan
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Bolloju S, Chiou CY, Vikramaditya T, Lee JT. (Pentafluorophenyl)diphenylphosphine as a dual-functional electrolyte additive for LiNi0.5Mn1.5O4 cathodes in high-voltage lithium-ion batteries. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.01.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Schulz CE, Dutta AK, Izsák R, Pantazis DA. Systematic High-Accuracy Prediction of Electron Affinities for Biological Quinones. J Comput Chem 2018; 39:2439-2451. [PMID: 30281169 DOI: 10.1002/jcc.25570] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 08/06/2018] [Accepted: 08/07/2018] [Indexed: 11/07/2022]
Abstract
Quinones play vital roles as electron carriers in fundamental biological processes; therefore, the ability to accurately predict their electron affinities is crucial for understanding their properties and function. The increasing availability of cost-effective implementations of correlated wave function methods for both closed-shell and open-shell systems offers an alternative to density functional theory approaches that have traditionally dominated the field despite their shortcomings. Here, we define a benchmark set of quinones with experimentally available electron affinities and evaluate a range of electronic structure methods, setting a target accuracy of 0.1 eV. Among wave function methods, we test various implementations of coupled cluster (CC) theory, including local pair natural orbital (LPNO) approaches to canonical and parameterized CCSD, the domain-based DLPNO approximation, and the equations-of-motion approach for electron affinities, EA-EOM-CCSD. In addition, several variants of canonical, spin-component-scaled, orbital-optimized, and explicitly correlated (F12) Møller-Plesset perturbation theory are benchmarked. Achieving systematically the target level of accuracy is challenging and a composite scheme that combines canonical CCSD(T) with large basis set LPNO-based extrapolation of correlation energy proves to be the most accurate approach. Methods that offer comparable performance are the parameterized LPNO-pCCSD, the DLPNO-CCSD(T0 ), and the orbital optimized OO-SCS-MP2. Among DFT methods, viable practical alternatives are only the M06 and the double hybrids, but the latter should be employed with caution because of significant basis set sensitivity. A highly accurate yet cost-effective DLPNO-based coupled cluster approach is used to investigate the methoxy conformation effect on the electron affinities of ubiquinones found in photosynthetic bacterial reaction centers. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Christine E Schulz
- Fakultät für Chemie und Biochemie, Ruhr-Universität Bochum, 44780, Bochum, Germany
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Achintya Kumar Dutta
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Róbert Izsák
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstr. 34-36, 45470, Mülheim an der Ruhr, Germany
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
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Vikramaditya T, Chai JD, Lin ST. Impact of non-empirically tuning the range-separation parameter of long-range corrected hybrid functionals on ionization potentials, electron affinities, and fundamental gaps. J Comput Chem 2018; 39:2378-2384. [DOI: 10.1002/jcc.25575] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Revised: 07/16/2018] [Accepted: 07/26/2018] [Indexed: 02/02/2023]
Affiliation(s)
- Talapunur Vikramaditya
- Department of Chemical Engineering; National Taiwan University; No. 1, Sec. 4, Roosevelt Road, Taipei 10617 Taiwan
| | - Jeng-Da Chai
- Department of Physics; National Taiwan University; No. 1, Sec. 4, Roosevelt Road, Taipei 10617 Taiwan
| | - Shiang-Tai Lin
- Department of Chemical Engineering; National Taiwan University; No. 1, Sec. 4, Roosevelt Road, Taipei 10617 Taiwan
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