1
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Bickelhaupt FM, Fernández I. What defines electrophilicity in carbonyl compounds. Chem Sci 2024; 15:3980-3987. [PMID: 38487236 PMCID: PMC10935700 DOI: 10.1039/d3sc05595g] [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: 10/20/2023] [Accepted: 02/05/2024] [Indexed: 03/17/2024] Open
Abstract
The origin of the electrophilicity of a series of cyclohexanones and benzaldehydes is investigated using the activation strain model and quantitative Kohn-Sham molecular orbital (MO) theory. We find that this electrophilicity is mainly determined by the electrostatic attractions between the carbonyl compound and the nucleophile (cyanide) along the entire reaction coordinate. Donor-acceptor frontier molecular orbital interactions, on which the current rationale behind electrophilicity trends is based, appear to have little or no significant influence on the reactivity of these carbonyl compounds.
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Affiliation(s)
- F Matthias Bickelhaupt
- Department of Chemistry and Pharmaceutical Sciences, AIMMS, Vrije Universiteit Amsterdam The Netherlands
- Institute for Molecules and Materials (IMM), Radboud University Nijmegen The Netherlands
- Department of Chemical Sciences, University of Johannesburg South Africa
| | - Israel Fernández
- Departamento de Química Orgánica, Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas, Universidad Complutense de Madrid Ciudad Universitaria 28040-Madrid Spain
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2
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Nieuwland C, Verdijk R, Fonseca Guerra C, Bickelhaupt FM. More Electropositive is More Electronegative: Atom Size Determines C=X Group Electronegativity. Chemistry 2023:e202304161. [PMID: 38117278 DOI: 10.1002/chem.202304161] [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: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 12/21/2023]
Abstract
Opposite to what one might expect, we find that the C=X group can become effectively more, not less, electronegative when the Pauling electronegativity of atom X decreases down Groups 16, 15, and 14 of the Periodic Table. Our quantum-chemical analyses, show that, and why, this phenomenon is a direct consequence of the increasing size of atom X down a group. These findings can be applied to tuning and improving the hydrogen-bond donor strength of amides H2 NC(=X)R by increasingly withdrawing density from the NH2 group. A striking example is that H2 NC(=SiR2 )R is a stronger hydrogen-bond donor than H2 NC(=CR2 )R.
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Affiliation(s)
- Celine Nieuwland
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
| | - Ron Verdijk
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
| | - Célia Fonseca Guerra
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
| | - F Matthias Bickelhaupt
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
- Department of Chemical Sciences, University of Johannesburg, Auckland Park, Johannesburg, 2006, South Africa
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3
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Saha HK, Mallick D, Das S. Dibenzoheterole-Fused s-Indacenes. J Org Chem 2023; 88:16248-16258. [PMID: 37943573 DOI: 10.1021/acs.joc.3c01719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
Heterole (pyrrole, thiophene, furan, thiophene-S,S-dioxide)-fused s-indacenes are known for their enhanced paratropic ring-current strength. However, the outcome of the antiaromatic properties for dibenzoheterole-fused s-indacene antiaromatics remained underexplored. Carbazole-, dibenzothiophene-, dibenzofuran-, and dibenzo[b,d]thiophene-5,5-dioxide-fused s-indacenes 1-4, respectively, were synthesized and characterized by experimental (NMR, single-crystal, UV-vis, CV) and computational (DFT) approaches to study the ground-state antiaromatic properties. Sulfone-containing 4 showed the weakest paratropic ring-current strength for the s-indacene unit, while 1-3 showed a relatively greater paratropicity for the s-indacene unit, as evidenced by the changes in 1H NMR chemical shifts of s-indacene protons. Such observation was explained by the electron-withdrawing effect of the sulfone group and loss of 4n + 2 aromaticity of the heterole unit for 4 reducing its s-indacene paratropicity strength as the nonaromaticity of the heterole unit reduces the π-bond character at the dibenzo[b,d]thiophene-5,5-dioxide/s-indacene fusion site to avoid antiaromatic s-indacene ring formation. The modulation of the paratropic ring-current strength of s-indacene for 1-4 was further supported by the NICS(1)zz and ring-current (ACID) calculations.
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Affiliation(s)
- Hemonta Kumar Saha
- Department of Chemistry, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India
| | - Dibyendu Mallick
- Department of Chemistry, Presidency University, Kolkata 700073, West Bengal, India
| | - Soumyajit Das
- Department of Chemistry, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India
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4
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Nieuwland C, Vermeeren P, Bickelhaupt FM, Fonseca Guerra C. Understanding chemistry with the symmetry-decomposed Voronoi deformation density charge analysis. J Comput Chem 2023; 44:2108-2119. [PMID: 37403918 DOI: 10.1002/jcc.27184] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 07/06/2023]
Abstract
The symmetry-decomposed Voronoi deformation density (VDD) charge analysis is an insightful and robust computational tool to aid the understanding of chemical bonding throughout all fields of chemistry. This method quantifies the atomic charge flow associated with chemical-bond formation and enables decomposition of this charge flow into contributions of (1) orbital interaction types, that is, Pauli repulsive or bonding orbital interactions; (2) per irreducible representation (irrep) of any point-group symmetry of interacting closed-shell molecular fragments; and now also (3) interacting open-shell (i.e., radical) molecular fragments. The symmetry-decomposed VDD charge analysis augments the symmetry-decomposed energy decomposition analysis (EDA) so that the charge flow associated with Pauli repulsion and orbital interactions can be quantified both per atom and per irrep, for example, for σ, π, and δ electrons. This provides detailed insights into fundamental aspects of chemical bonding that are not accessible from EDA.
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Affiliation(s)
- Celine Nieuwland
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Pascal Vermeeren
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - F Matthias Bickelhaupt
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Institute of Molecules and Materials, Radboud University Nijmegen, Nijmegen, The Netherlands
- Department of Chemical Sciences, University of Johannesburg, Johannesburg, South Africa
| | - Célia Fonseca Guerra
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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5
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Matias PMC, Murtinho D, Valente AJM. Triazine-Based Porous Organic Polymers: Synthesis and Application in Dye Adsorption and Catalysis. Polymers (Basel) 2023; 15:polym15081815. [PMID: 37111962 PMCID: PMC10143168 DOI: 10.3390/polym15081815] [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: 03/17/2023] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 04/29/2023] Open
Abstract
The scientific community has been developing promising materials to increase the sustainability and efficiency of production processes and pollutant environmental remediation strategies. Porous organic polymers (POPs) are of special interest, as they are insoluble custom-built materials at the molecular level, endowed with low densities and high stability, surface areas, and porosity. This paper describes the synthesis, characterization, and performance of three triazine-based POPs (T-POPs) in dye adsorption and Henry reaction catalysis. T-POPs were prepared by a polycondensation reaction between melamine and a dialdehyde (terephthalaldehyde (T-POP1) or isophthalaldehyde derivatives with a hydroxyl group (T-POP2) or both a hydroxyl and a carboxyl group (T-POP3)). The crosslinked and mesoporous polyaminal structures, with surface areas between 139.2 and 287.4 m2 g-1, positive charge, and high thermal stability, proved to be excellent methyl orange adsorbents, removing the anionic dye with an efficiency >99% in just 15-20 min. The POPs were also effective for methylene blue cationic dye removal from water, reaching efficiencies up to ca. 99.4%, possibly due to favorable interactions via deprotonation of T-POP3 carboxyl groups. The modification of the most basic polymers, T-POP1 and T-POP2, with copper(II) allowed the best efficiencies in Henry reactions catalysis, leading to excellent conversions (97%) and selectivities (99.9%).
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Affiliation(s)
- Pedro M C Matias
- Department of Chemistry, CQC-IMS, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal
| | - Dina Murtinho
- Department of Chemistry, CQC-IMS, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal
| | - Artur J M Valente
- Department of Chemistry, CQC-IMS, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal
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6
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Baidya A, Ghovvati M, Lu C, Naghsh-Nilchi H, Annabi N. Designing a Nitro-Induced Sutured Biomacromolecule to Engineer Electroconductive Adhesive Hydrogels. ACS APPLIED MATERIALS & INTERFACES 2022; 14:49483-49494. [PMID: 36286540 DOI: 10.1021/acsami.2c11348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Nitro-functionality, with a large deficit of negative charge, embraces biological importance and has proven its therapeutic essence even in chemotherapy. Functionally, with its strong electron-withdrawing capability, nitro can manipulate the electron density of organic moieties and regulates cellular-biochemical reactions. However, the chemistry of nitro-functionality to introduce physiologically relevant macroscopic properties from the molecular skeleton is unknown. Therefore, herein, a neurotransmitter moiety, dopamine, was chemically modified with a nitro-group to explore its influence on synthesizing a multifunctional biomaterial for therapeutic applications. Chemically, while the nitro-group perturbed the aromatic electron density of nitrocatecholic domain, it facilitated the suturing of nitrocatechol moieties to regain its aromaticity through a radical transfer mechanism, forming a novel macromolecular structure. Incorporation of the sutured-nitrocatecholic strand (S-nCAT) in a gelatin-based hydrogel introduced an electroconductive microenvironment through the delocalization of π-electrons in S-nCAT, while maintaining its catechol-mediated adhesive property for tissue repairing/sealing. Meanwhile, the engineered hydrogel enriched with noncovalent interactions, demonstrated excellent mechano-physical properties to support tissue functions. Cytocompatibility of the bioadhesive was assessed with in vitro and in vivo studies, confirming its potential usage for biomedical applications. In conclusion, this novel chemical approach enabled designing a multifunctional biomaterial by manipulating the electronic properties of small bioactive molecules for various biomedical applications.
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Affiliation(s)
- Avijit Baidya
- Department of Chemical and Biomolecular Engineering, University of California-Los Angeles, Los Angeles, California90095, United States
| | - Mahsa Ghovvati
- Department of Chemical and Biomolecular Engineering, University of California-Los Angeles, Los Angeles, California90095, United States
| | - Cathy Lu
- Department of Chemical and Biomolecular Engineering, University of California-Los Angeles, Los Angeles, California90095, United States
| | - Hamed Naghsh-Nilchi
- Department of Bioengineering, University of California-Los Angeles, Los Angeles, California90095, United States
| | - Nasim Annabi
- Department of Chemical and Biomolecular Engineering, University of California-Los Angeles, Los Angeles, California90095, United States
- Department of Bioengineering, University of California-Los Angeles, Los Angeles, California90095, United States
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7
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Blokker E, van Zeist W, Sun X, Poater J, van der Schuur JM, Hamlin TA, Bickelhaupt FM. Methyl Substitution Destabilizes Alkyl Radicals. Angew Chem Int Ed Engl 2022; 61:e202207477. [PMID: 35819818 PMCID: PMC9545886 DOI: 10.1002/anie.202207477] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Indexed: 12/02/2022]
Abstract
We have quantum chemically investigated how methyl substituents affect the stability of alkyl radicals MemH3−mC⋅ and the corresponding MemH3−mC−X bonds (X = H, CH3, OH; m = 0 – 3) using density functional theory at M06‐2X/TZ2P. The state‐of‐the‐art in physical organic chemistry is that alkyl radicals are stabilized upon an increase in their degree of substitution from methyl<primary<secondary<tertiary, and that this is the underlying cause for the decrease in C−H bond strength along this series. Here, we provide evidence that falsifies this model and show that, on the contrary, the MemH3−mC⋅ radical is destabilized with increasing substitution. The reason that the corresponding C−H bond nevertheless becomes weaker is that substitution destabilizes the sterically more congested MemH3−mC−H molecule even more.
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Affiliation(s)
- Eva Blokker
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
| | - Willem‐Jan van Zeist
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
| | - Xiaobo Sun
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
- Departament de Química Inorgànica i Orgànica & IQTCUB Universitat de Barcelona Martí i Franquès 1–11 08028 Barcelona Spain
| | - Jordi Poater
- Departament de Química Inorgànica i Orgànica & IQTCUB Universitat de Barcelona Martí i Franquès 1–11 08028 Barcelona Spain
- ICREA Pg. Lluís Companys 23 08010 Barcelona Spain
| | | | - Trevor A. Hamlin
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
| | - F. Matthias Bickelhaupt
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
- Institute of Molecules and Materials Radboud University Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
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8
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Blokker E, van Zeist WJ, Sun X, Poater J, van der Schuur JM, Hamlin TA, Bickelhaupt FM. Methyl Substitution Destabilizes Alkyl Radicals. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202207477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Eva Blokker
- Vrije Universiteit Amsterdam Department of Theoretical Chemistry NETHERLANDS
| | | | - Xiaobo Sun
- Universitat de Barcelona CRAI: Universitat de Barcelona Departament de Química Inorgànica i Orgànica SPAIN
| | - Jordi Poater
- Universitat de Barcelona Departament de Química Inorgànica i Orgànica SPAIN
| | | | - Trevor A. Hamlin
- Vrije Universiteit Amsterdam Department of Theoretical Chemistry NETHERLANDS
| | - F. Matthias Bickelhaupt
- VU University Amsterdam Theoretical Chemistry De Boelelaan 1083 1081 HV Amsterdam NETHERLANDS
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9
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Nieuwland C, Fonseca Guerra C. How the Chalcogen Atom Size Dictates the Hydrogen‐Bond Donor Capability of Carboxamides, Thioamides, and Selenoamides. Chemistry 2022; 28:e202200755. [PMID: 35322485 PMCID: PMC9324920 DOI: 10.1002/chem.202200755] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Indexed: 12/21/2022]
Abstract
The amino groups of thio‐ and selenoamides can act as stronger hydrogen‐bond donors than of carboxamides, despite the lower electronegativity of S and Se. This phenomenon has been experimentally explored, particularly in organocatalysis, but a sound electronic explanation is lacking. Our quantum chemical investigations show that the NH2 groups in thio‐ and selenoamides are more positively charged than in carboxamides. This originates from the larger electronic density flow from the nitrogen lone pair of the NH2 group towards the lower‐lying π*C=S and π*C=Se orbitals than to the high‐lying π*C=O orbital. The relative energies of the π* orbitals result from the overlap between the chalcogen np and carbon 2p atomic orbitals, which is set by the carbon‐chalcogen equilibrium distance, a consequence of the Pauli repulsion between the two bonded atoms. Thus, neither the electronegativity nor the often‐suggested polarizability but the steric size of the chalcogen atom determines the amide's hydrogen‐bond donor capability.
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Affiliation(s)
- Celine Nieuwland
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
| | - Célia Fonseca Guerra
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
- Leiden Institute of Chemistry Gorlaeus Laboratories Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands
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10
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Kamal S, Inamdar AI, Chiou K, Sainbileg B, Usman M, Chen J, Luo T, Hayashi M, Hung C, Liaw W, Lu K. Functional Groups Assisted Tunable Dielectric Permittivity of Guest‐Free Zn‐Based Coordination Polymers for Gate Dielectrics. Chemistry 2022; 28:e202103905. [DOI: 10.1002/chem.202103905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Indexed: 11/11/2022]
Affiliation(s)
- Saqib Kamal
- Institute of Chemistry Academia Sinica Taipei 115 Taiwan
- Molecular Science and Technology Taiwan International Graduate Program Institute of Atomic and Molecular Science Academia Sinica Taipei 115 & Department of Chemistry National Tsing Hua University Hsinchu 300 Taiwan
- Department of Chemistry Fu Jen Catholic University New Taipei City 242 Taiwan
| | | | - Kuan‐Ru Chiou
- Department of Physics National Taiwan University Taipei 106 Taiwan
| | - Batjargal Sainbileg
- Center for Condensed Matter Sciences National Taiwan University & Center of Atomic Initiative for New Materials National Taiwan University Taipei 106 Taiwan
| | - Muhammad Usman
- Institute of Chemistry Academia Sinica Taipei 115 Taiwan
| | - Jenq‐Wei Chen
- Department of Physics National Taiwan University Taipei 106 Taiwan
| | | | - Michitoshi Hayashi
- Center for Condensed Matter Sciences National Taiwan University & Center of Atomic Initiative for New Materials National Taiwan University Taipei 106 Taiwan
| | | | - Wen‐Feng Liaw
- Molecular Science and Technology Taiwan International Graduate Program Institute of Atomic and Molecular Science Academia Sinica Taipei 115 & Department of Chemistry National Tsing Hua University Hsinchu 300 Taiwan
| | - Kuang‐Lieh Lu
- Institute of Chemistry Academia Sinica Taipei 115 Taiwan
- Department of Chemistry Fu Jen Catholic University New Taipei City 242 Taiwan
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11
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Rani M, Shanker U. Sunlight-induced photocatalytic degradation of organic pollutants by biosynthesized hetrometallic oxides nanoparticles. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:61760-61780. [PMID: 34189687 DOI: 10.1007/s11356-021-15003-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 06/15/2021] [Indexed: 06/13/2023]
Abstract
Dyes and phenols are extensively used chemicals in petrochemicals, pharmaceuticals, textile, and paints industries. Due to high persistence, bioaccumulation, and toxicity, their removal from the environment is highly imperative by advanced techniques. Single metal oxide nanomaterials are generally associated with limitations of large bandgap (> 3eV) and charge recombination. Therefore, heterometallic oxides (HMOs) as CuFe2O4, CuMn2O4, and MnZn2O4 have been synthesized via green route by employing leaf extract of Azadirachta indica. XRD revealed the crystalline nature of HMOs nanospheres with particle size less than 100 nm. Subsequently, HMOs nanocatalysts were used as photocatalyst for removal of 3-amino phenols (3-AP) and eriochrome black T (EBT) from water under sunlight. Reaction parameters namely pollutant concentration (50-130 mgL-1), catalyst dose (20-100 mg), and pH (3-11) were optimized in order to get best results. Substantial degradation (80-95%) of pollutants (50 mgL-1) by HMOs (80 mg) was achieved at neutral pH under sunlight exposure. Highest removal by CuFe2O4 might be due to its high surface area (35.7 m2g-1), low band gap (2.4 eV), larger particle stability (Zeta potential: -22.0 mV), and lower photoluminescence intensity. Sharp declines in curves were visually confirmed by color change and indicated for first-order kinetics of degradation with initial Langmuir adsorption. Spectrophotometric analysis revealed that half-life (t1/2) of 3-AP (0.9-1.7 h) and EBT (0.6-0.8 h) were significantly reduced. Faster degradation of EBT than 3-AP was because of less electronegative N-atom at the diazo group. Scavenger analysis indicated the presence of active radicals in photo-catalytic degradation of 3-AP and EBT. All HMOs have shown high reusability (n=8) which ensures their stability, sustainability, and efficiency. Overall, green synthesized HMOs nanoparticles with prominent surface characteristics offer a viable alternative photocatalyst for industrial applications.
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Affiliation(s)
- Manviri Rani
- Department of Chemistry, Malaviya National Institute of Technology Jaipur, Jaipur, Rajasthan, 302017, India.
| | - Uma Shanker
- Department of Chemistry, Dr B R Ambedkar National Institute of Technology Jalandhar, Jalandhar, Punjab, 144011, India.
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12
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Nieuwland C, Zaccaria F, Fonseca Guerra C. Understanding alkali metal cation affinities of multi-layer guanine quadruplex DNA. Phys Chem Chem Phys 2021; 22:21108-21118. [PMID: 32954397 PMCID: PMC8612728 DOI: 10.1039/d0cp03433a] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To gain better understanding of the stabilizing interactions between metal ions and DNA quadruplexes, dispersion-corrected density functional theory (DFT-D) based calculations were performed on double-, triple- and four-layer guanine tetrads interacting with alkali metal cations. All computations were performed in aqueous solution that mimics artificial supramolecular conditions where guanine bases assemble into stacked quartets as well as biological environments in which telomeric quadruplexes are formed. To facilitate the computations on these significant larger systems, optimization of the DFT description was performed first by evaluating the performance of partial reduced basis sets. Analysis of the stabilizing interactions between alkali cations and the DNA bases in double and triple-layer guanine quadruplex DNA reproduced the experimental affinity trend of the order Li+< Rb+ < Na+ < K+. The desolvation and the size of alkali metal cations are thought to be responsible for the order of affinity. Nevertheless, for the alkali metal cation species individually, the magnitude of the bond energy stays equal for binding as first, second or third cation in double, triple and four-layer guanine quadruplexes, respectively. This is the result of an interplay between a decreasingly stabilizing interaction energy and increasingly stabilizing solvation effects, along the consecutive binding events. This diminished interaction energy is the result of destabilizing electrostatic repulsion between the hosted alkali metal cations. This work emphasizes the stabilizing effect of aqueous solvent on large highly charged biomolecules. Stabilizing solvent effects and electrostatic repulsion are responsible for the constant alkali metal cation affinity in multi-layer guanine quadruplexes.![]()
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Affiliation(s)
- C Nieuwland
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modelling, AIMMS, Vrije Universiteit Amsterdam, De Boelelaan 1085 NL-1081HV Amsterdam, The Netherlands.
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13
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Southouse JP, Lazzarini L, Ibhadon AO, Francesconi MG. Ultra-small FeS 2 nanoparticles for highly efficient chemoselective transfer hydrogenation of nitroarenes. NEW J CHEM 2021. [DOI: 10.1039/d1nj03297f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Ultra-small FeS2 nanoparticles are shown to give superior catalytic performance in hydrogen transfer reactions for the synthesis of substituted anilines.
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Affiliation(s)
- Jamie P. Southouse
- Department of Chemical Engineering, University of Hull, Cottingham Road, Hull, HU6 7RX, UK
| | | | - Alex O. Ibhadon
- Department of Chemical Engineering, University of Hull, Cottingham Road, Hull, HU6 7RX, UK
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14
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van der Lubbe SC, Haim A, van Heesch T, Fonseca Guerra C. Tuning the Binding Strength of Even and Uneven Hydrogen-Bonded Arrays with Remote Substituents. J Phys Chem A 2020; 124:9451-9463. [PMID: 33054218 PMCID: PMC7667637 DOI: 10.1021/acs.jpca.0c07815] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/01/2020] [Indexed: 12/20/2022]
Abstract
We investigated the tunability of hydrogen bond strength by altering the charge accumulation around the frontier atoms with remote substituents. For pyridine···H2O with NH2 and CN substituted at different positions on pyridine, we find that the electron-withdrawing CN group decreases the negative charge accumulation around the frontier atom N, resulting in weakening of the hydrogen bond, whereas the electron-donating NH2 group increases the charge accumulation around N, resulting in strengthening of the hydrogen bond. By applying these design principles on DDAA-AADD, DADA-ADAD, DAA-ADD, and ADA-DAD hydrogen-bonded dimers, we find that the effect of the substituent is delocalized over the whole molecular system. As a consequence, systems with an equal number of hydrogen bond donor (D) and acceptor (A) atoms are not tunable in a predictable way because of cancellation of counteracting strengthening and weakening effects. Furthermore, we show that the position of the substituent and long-range electrostatics can play an important role as well. Overall, the design principles presented in this work are suitable for monomers with an unequal number of donor and acceptor atoms and can be exploited to tune the binding strength of supramolecular building blocks.
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Affiliation(s)
- Stephanie
C. C. van der Lubbe
- Department
of Theoretical Chemistry, Amsterdam Institute of Molecular and Life
Sciences (AIMMS), Amsterdam Center of Multiscale
Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
| | - Anissa Haim
- Department
of Theoretical Chemistry, Amsterdam Institute of Molecular and Life
Sciences (AIMMS), Amsterdam Center of Multiscale
Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
| | - Thor van Heesch
- Department
of Theoretical Chemistry, Amsterdam Institute of Molecular and Life
Sciences (AIMMS), Amsterdam Center of Multiscale
Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
| | - Célia Fonseca Guerra
- Department
of Theoretical Chemistry, Amsterdam Institute of Molecular and Life
Sciences (AIMMS), Amsterdam Center of Multiscale
Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
- Leiden
Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg
55, 2333 CD Leiden, The Netherlands
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15
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Apaza Ticona L, Tena Pérez V, Serban AM, Sánchez‐Corral J, Rumbero Sánchez Á. Design, Synthesis and Pharmacological Evaluation of
N
‐Benzyl Linoleamide Analogues from
Tropaeolum tuberosum
as NF‐κB Inhibitors and Nrf2 Activators. ChemistrySelect 2020. [DOI: 10.1002/slct.202003062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Luis Apaza Ticona
- Department of Organic Chemistry Faculty of Sciences University Autónoma of Madrid Cantoblanco 28049 Madrid Spain
- Department of Pharmacology Pharmacognosy and Botany Faculty of Pharmacy University Complutense of Madrid Ciudad Universitaria s/n 28040 Madrid Spain
| | - Víctor Tena Pérez
- Department of Organic Chemistry Faculty of Sciences University Autónoma of Madrid Cantoblanco 28049 Madrid Spain
| | - Andreea Madalina Serban
- Maria Sklodowska Curie University Hospital for Children Constantin Brancoveanu Boulevard 077120 Bucharest Romania
| | - Javier Sánchez‐Corral
- Department of Organic Chemistry Faculty of Sciences University Autónoma of Madrid Cantoblanco 28049 Madrid Spain
| | - Ángel Rumbero Sánchez
- Department of Organic Chemistry Faculty of Sciences University Autónoma of Madrid Cantoblanco 28049 Madrid Spain
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16
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Bragato M, von Rudorff GF, von Lilienfeld OA. Data enhanced Hammett-equation: reaction barriers in chemical space. Chem Sci 2020; 11:11859-11868. [PMID: 34094415 PMCID: PMC8163012 DOI: 10.1039/d0sc04235h] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/02/2020] [Indexed: 11/21/2022] Open
Abstract
It is intriguing how the Hammett equation enables control of chemical reactivity throughout chemical space by separating the effect of substituents from chemical process variables, such as reaction mechanism, solvent, or temperature. We generalize Hammett's original approach to predict potential energies of activation in non aromatic molecular scaffolds with multiple substituents. We use global regression to optimize Hammett parameters ρ and σ in two experimental datasets (rate constants for benzylbromides reacting with thiols and ammonium salt decomposition), as well as in a synthetic dataset consisting of computational activation energies of ∼2400 SN2 reactions, with various nucleophiles and leaving groups (-H, -F, -Cl, -Br) and functional groups (-H, -NO2, -CN, -NH3, -CH3). Individual substituents contribute additively to molecular σ with a unique regression term, which quantifies the inductive effect. The position dependence of substituents can be modeled by a distance decaying factor for SN2. Use of the Hammett equation as a base-line model for Δ-machine learning models of the activation energy in chemical space results in substantially improved learning curves reaching low prediction errors for small training sets.
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Affiliation(s)
- Marco Bragato
- Institute of Physical Chemistry and National Center for Computational Design and Discovery of Novel Materials (MARVEL), Department of Chemistry, University of Basel Klingelbergstrasse 80 CH-4056 Basel Switzerland
| | - Guido Falk von Rudorff
- Institute of Physical Chemistry and National Center for Computational Design and Discovery of Novel Materials (MARVEL), Department of Chemistry, University of Basel Klingelbergstrasse 80 CH-4056 Basel Switzerland
| | - O Anatole von Lilienfeld
- Institute of Physical Chemistry and National Center for Computational Design and Discovery of Novel Materials (MARVEL), Department of Chemistry, University of Basel Klingelbergstrasse 80 CH-4056 Basel Switzerland
- Faculty of Physics, University of Vienna Kolingasse 14-16 AT 1090 Vienna Austria
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17
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Tena Pérez V, Apaza Ticona L, Serban AM, Acero Gómez J, Rumbero Sánchez Á. Synthesis and biological screening of a library of macamides as TNF-α inhibitors. RSC Med Chem 2020; 11:1196-1209. [PMID: 33479624 DOI: 10.1039/d0md00208a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 07/27/2020] [Indexed: 11/21/2022] Open
Abstract
Thirty-five macamide analogues were synthesised by modifying the initial molecular structure. The resulting structures were confirmed using NMR and MS. Cytotoxicity and the anti-inflammatory activity of these synthetic macamides were evaluated in the THP-1 cell line. Preliminary biological evaluation indicated that most of these synthetic macamides did not present cytotoxicity (MTT assay) in the tested cell line with respect to the control (actinomycin D). Regarding the anti-inflammatory activity, several analogues had a greater potential for inhibition of TNF-α than natural macamides. Synthetic macamide 4a was the most active (IC50 = 0.009 ± 0.001 μM) compared to the C87 (control). Through looking at the link between the chemical structure and the activity, our study proves that changes made to natural macamides at the level of the alkyl chain, the benzyl position, the amide bond, and the addition of two methyl groups to the aromatic ring (meta position) lead us to obtaining new macamides with greater anti-inflammatory activity.
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Affiliation(s)
- Víctor Tena Pérez
- Department of Organic Chemistry , Faculty of Sciences , University Autónoma of Madrid , Cantoblanco , 28049 Madrid , Spain . ;
| | - Luis Apaza Ticona
- Department of Organic Chemistry , Faculty of Sciences , University Autónoma of Madrid , Cantoblanco , 28049 Madrid , Spain . ; .,Department of Pharmacology, Pharmacognosy and Botany , Faculty of Pharmacy , University Complutense of Madrid , Ciudad Universitaria s/n , 28040 Madrid , Spain
| | - Andreea Madalina Serban
- Maria Sklodowska Curie University Hospital for Children , Constantin Brancoveanu Boulevard , 077120 Bucharest , Romania
| | - Javier Acero Gómez
- Department of Organic Chemistry , Faculty of Sciences , University Autónoma of Madrid , Cantoblanco , 28049 Madrid , Spain . ;
| | - Ángel Rumbero Sánchez
- Department of Organic Chemistry , Faculty of Sciences , University Autónoma of Madrid , Cantoblanco , 28049 Madrid , Spain . ;
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18
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Abstract
AbstractNumerous studies on nitro group properties are associated with its high electron-withdrawing ability, by means of both resonance and inductive effect. The substituent effect of the nitro group may be well described using either traditional substituent constants or characteristics based on quantum chemistry, i.e., cSAR, SESE, and pEDA/sEDA models. Interestingly, the cSAR descriptor allows to describe the electron-attracting properties of the nitro group regardless of the position and the type of system. Analysis of classical and reverse substituent effects of the nitro group in various systems indicates strong pi-electron interactions with electron-donating substituents due to the resonance effect. This significantly affects the pi-electron delocalization of the aromatic ring decreasing the aromatic character, evidenced clearly by HOMA values. Use of the pEDA/sEDA model allows to measure the population of electrons transferred from the ring to the nitro group.
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19
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Jezuita A, Szatylowicz H, Krygowski TM. How amino and nitro substituents affect the aromaticity of benzene ring. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137567] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Thevendran R, Sarah S, Tang TH, Citartan M. Strategies to bioengineer aptamer-driven nanovehicles as exceptional molecular tools for targeted therapeutics: A review. J Control Release 2020; 323:530-548. [PMID: 32380206 DOI: 10.1016/j.jconrel.2020.04.051] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 02/06/2023]
Abstract
Aptamers are a class of folded nucleic acid strands capable of binding to different target molecules with high affinity and selectivity. Over the years, they have gained a substantial amount of interest as promising molecular tools for numerous medical applications, particularly in targeted therapeutics. However, only the different treatment approaches and current developments of aptamer-drug therapies have been discussed so far, ignoring the crucial technical and functional aspects of constructing a therapeutically effective aptamer-driven drug delivery system that translates to improved in-vivo performance. Hence, this paper provides a comprehensive review of the strategies used to improve the therapeutic performance of aptamer-guided delivery systems. We focus on the different functional features such as drug deployment, payload capacity, in-vivo stability and targeting efficiency to further our knowledge in enhancing the cell-specific delivery of aptamer-drug conjugates. Each reported strategy is critically discussed to emphasize both the benefits provided in comparison with other similar techniques and to outline their potential drawbacks with respect to the molecular properties of the aptamers, the drug and the system to be designed. The molecular architecture and design considerations for an efficient aptamer-based delivery system are also briefly elaborated.
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Affiliation(s)
- Ramesh Thevendran
- Advanced Medical & Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia.
| | - Shigdar Sarah
- School of Medicine, Deakin University, Pigdons Road, Waurn Ponds, Victoria 3216, Australia
| | - Thean-Hock Tang
- Advanced Medical & Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia.
| | - Marimuthu Citartan
- Advanced Medical & Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia.
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21
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Chow CH, Sze-Yin Leung K. Transformations of organic micropollutants undergoing permanganate/bisulfite treatment: Kinetics, pathways and toxicity. CHEMOSPHERE 2019; 237:124524. [PMID: 31549647 DOI: 10.1016/j.chemosphere.2019.124524] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 07/28/2019] [Accepted: 08/04/2019] [Indexed: 06/10/2023]
Abstract
Permanganate/bisulfite (PM/BS) is a relatively new advanced oxidation process that can degrade organic micropollutants at extraordinary high rates. In this study, the degradability of PM/BS process towards different representative types of compounds was studied by investigating the kinetics, reaction site specificity and transformation chemistry. Acesulfame (ACE) and carbamazepine (CBZ) were two typical compounds containing olefinic moieties. Sucralose (SUC) was selected as a reference compound, and it is without aromatic and olefinic moieties. The kinetics results indicated that ACE and CBZ were effectively degraded while SUC was not. Preferred reaction sites of Mn3+ species was elucidated by identification of the ACE-transformation products (TPs) and CBZ-TPs with UHPLC-QTOF-MS. Seventeen ACE-TPs including two new compounds and eleven CBZ-TPs produced during the PM/BS process were identified and characterized. Transformation pathways revealed that cleavage of olefinic double bonds was the main reaction mechanism. Chemical structures containing electron-donating groups preferentially reacted with electrophilic Mn3+ species during the process. In addition, transformation products of ACE and CBZ during PM/BS process did not induce higher toxicity. This study provides a preliminary interpretation on the selectivity of PM/BS process according to the micropollutants' chemical structures, which hope to shed light on the future development of PM/BS treatment.
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Affiliation(s)
- Chi-Hang Chow
- Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region
| | - Kelvin Sze-Yin Leung
- Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region; HKBU Institute of Research and Continuing Education, Shenzhen Virtual University Park, Shenzhen, China.
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22
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Wang H, Zhu C, Liu L, Ma S, Liu P, Wu J, Shi C, Du Q, Hao Y, Xiang S, Chen H, Chen P, Bai Y, Zhou H, Li Y, Chen Q. Interfacial Residual Stress Relaxation in Perovskite Solar Cells with Improved Stability. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1904408. [PMID: 31617644 DOI: 10.1002/adma.201904408] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/24/2019] [Indexed: 06/10/2023]
Abstract
To improve the photovoltaic performance (both efficiency and stability) in hybrid organic-inorganic halide perovskite solar cells, perovskite lattice distortion is investigated with regards to residual stress (and strain) in the polycrystalline thin films. It is revealed that residual stress is concentrated at the surface of the as-prepared film, and an efficient method is further developed to release this interfacial stress by A site cation alloying. This results in lattice reconstruction at the surface of polycrystalline thin films, which in turn results in low elastic modulus. Thus, a "bone-joint" configuration is constructed within the interface between the absorber and the carrier transport layer, which improves device performance substantially. The resultant photovoltaic devices exhibit an efficiency of 21.48% with good humidity stability and improved resistance against thermal cycling.
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Affiliation(s)
- Hao Wang
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Cheng Zhu
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Lang Liu
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Sai Ma
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Pengfei Liu
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Jiafeng Wu
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Congbo Shi
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Qin Du
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Yanmin Hao
- Center for Testing and Analyzing of Materials, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, P. R. China
| | - Sisi Xiang
- School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing, 100191, P. R. China
| | - Haining Chen
- School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing, 100191, P. R. China
| | - Pengwan Chen
- State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Yang Bai
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Huanping Zhou
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, 100871, P. R. China
| | - Yujing Li
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Qi Chen
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
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23
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Dey S, Manogaran D, Manogaran S, Schaefer HF. Substituent effects on the aromaticity of benzene-An approach based on interaction coordinates. J Chem Phys 2019; 150:214108. [PMID: 31176350 DOI: 10.1063/1.5090588] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Benzene and 23 monosubstituted and 32 disubstituted derivatives of benzene were optimized for minimum energy structures using the B3LYP/cc-pVTZ method. The force fields of all the compounds were evaluated at their optimized geometries using the same method and basis set. In order to understand the effect of substitution(s) on the aromaticity of benzene, the aromaticity index based on interaction coordinates (AIBIC) values were computed for each and the change from the benzene value was obtained. This difference, the substituent effect based on interaction coordinates (SEBIC), quantifies the effect of the substituent on the aromaticity of benzene ring satisfactorily. It is found that the AIBIC of disubstituted benzenes (XC6H4Y) could be predicted well by adding the respective SEBIC(C6H5X) and SEBIC(C6H5Y) values to the AIBIC of benzene. The projected force fields of the meta and para fragments of the monosubstituted benzenes when chosen properly contain the information about the directing influence of the substituent in terms of the electron density based on interaction coordinates (EDBIC). When the EDBIC(para) > EDBIC(meta) relative to benzene, the substituent is ortho-para directing, while when the reverse is true, it is meta directing. The effect of conformational changes on aromaticity has been studied using aminophenols and dihydroxybenzenes. The additivity rule and the EDBIC concept work adequately well in that the methods can have several useful practical applications that will benefit various areas of science. A good understanding of the substituent effects and the ability to predict them should add a new dimension to the applications of AIBIC.
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Affiliation(s)
- Soumyadeb Dey
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India
| | - Dhivya Manogaran
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India
| | - Sadasivam Manogaran
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
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24
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Scarborough TD, McAcy CJ, Beck J, Uiterwaal CJGJ. Comparison of ultrafast intense-field photodynamics in aniline and nitrobenzene: stability under amino and nitro substitution. Phys Chem Chem Phys 2019; 21:6553-6558. [PMID: 30848265 DOI: 10.1039/c8cp07866a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report on the photoionization and photofragmentation of aniline (C6H5NH2) and nitrobenzene (C6H5NO2) under single-molecule conditions in the focus of 50 fs, 800 nm laser pulses. Ion mass spectra are recorded as a function of intensity ranging from 6 × 1012 to 3 × 1014 W cm-2. Ion yields are measured in the absence of the focal volume effect and without the need for additional deconvolution of data. We observe evidence of resonance-enhanced multiphoton ionization in aniline, in agreement with current literature. Phenyl-based ion fragments, singly-charged parent ions, and dissociative rearrangement processes are observed for both molecules. However, fragmentation in aniline is heavily suppressed in favor of parent ionization while the reverse is true for nitrobenzene, and multiply-charged parent ions are present in aniline and absent in nitrobenzene. We discuss the implications of these and other results as they relate to molecular stability against intense-field ionization and fragmentation, specifically with regards to the opposing behavior of the substituted amino and nitro functional groups.
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Affiliation(s)
- Timothy D Scarborough
- Physics Research Building, Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA.
| | - Collin J McAcy
- Theodore Jorgensen Hall, Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Joshua Beck
- Theodore Jorgensen Hall, Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Cornelis J G J Uiterwaal
- Theodore Jorgensen Hall, Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
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25
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Yourdkhani S, Chojecki M, Korona T. Substituent effects in the so-called cationπ interaction of benzene and its boron-nitrogen doped analogues: overlooked role of σ-skeleton. Phys Chem Chem Phys 2019; 21:6453-6466. [PMID: 30839951 DOI: 10.1039/c8cp04962a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Despite massive efforts to pinpoint the substituent effects in the so-called cationπ systems, no consensus has been yet reached on how substituents exercise their effects in the interaction of the aromatic molecule with the metal ion. The π-polarization (the Hunter model) and the direct local effect (the Wheeler-Houk model) are two lines of thought applied to this problem, but the justification of both approaches is based on insufficiently proven assumptions and approximations. In order to shed more light on this issue we propose a new approach which enables us to gauge directly the energetic trends resulting from the interaction of the ring with the cation. In our method we add one more partitioning level to the interacting quantum atoms (IQA) scheme and decompose the IQA interaction energies into contributions resulting from σ and π electron densities of the aromatic ring. The new approach, which is named partitioned-IQA, abbreviated as p-IQA, has been applied to complexes of derivatives of benzene or azaborine interacting with a sodium cation. The p-IQA approach reveals that in these systems both σ and π electronic moieties are polarized. Interestingly, for the majority of cases the σ-polarization outweighs the π one, contrary to the Hunter model. However, the Wheeler-Houk model is not precise, either, since the σ-polarization shows some degree of non-locality. In addition, the substituents are found to have a negligible influence on the ring orbital-overlapping capability, i.e. the covalency. Therefore, the substituent effect in the cationπ interaction is a nonlocal classical effect, indicating that neither Hunter model nor Wheeler-Houk model is able to fully describe all the aspects of the substituent effects. The p-IQA conclusions for the considered systems have been compared with the results from the functional-group SAPT (F-SAPT) method. We believe that the presented partitioning in the IQA framework will provide a deeper insight into the substituent effects in the cationπ interactions, which is beyond the σ-π atomic charge population separation.
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Affiliation(s)
- Sirous Yourdkhani
- Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, CZ-12116 Prague 2, Czech Republic.
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26
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Burnea FKB, Ko KC, Lee JY. Effective modulation of intramolecular ferromagnetic interaction of diradicals by functionalization of cross-conjugated coupler. Phys Chem Chem Phys 2018; 20:20688-20694. [PMID: 30062363 DOI: 10.1039/c8cp03689f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cross-conjugated molecules are an interesting class of conjugated systems possessing a spatially separated HOMO and LUMO. Most previous studies have taken advantage of this property by using it in organic semiconductor applications. Herein, we undertake a new investigation on the use of this type of molecule, in particular benzo[1,2-d;4,5-d']bisoxazole (BBO), as a coupler for organic diradicals. BBO has two sites available for adding a substituent and a spin center (SC) which are along its 4,8- and 2,6-axes. Functionalizations using electron donating (ED) and electron withdrawing (EW) groups were imposed to tune its FMOs and it was found that the longer 2,6-axis is an ideal site with a broader LUMO range via substituent effects. Diradicalization of these BBOs using nitronyl nitroxide (NN) and nitroxide (NO) as SCs was done using the remaining available axis. The calculated J values are linearly dependent on the LUMO energy of the coupler, but with 4,8-NH2-2,6-SC as an outlier. This exceptional case is related to 4,8-NH2-2,6-SC having the lowest BBO-NN dihedral angle. Moreover, the diradicals 4,8-X-2,6-SC (with X = H, NH2, CH3) have higher J values than 2,6-X-4,8-SC (with X = H, NH2, CH3), which is counterintuitive because the latter have a shorter coupling path. These diradicals are positioned to the right of the intersection of their trend lines, which implies that diradicals with LUMO values to the right of this intersection have the tendency to attain J values that are higher than those diradicals with a shorter coupling path. 4,8-NH2-2,6-SC even surpasses the projected JMax values which we associate with the highest attainable J values due to LUMO tuning via substituent effects. These results provide useful insights, especially into the interplay between the LUMO and the dihedral angle and how these affect magnetism in diradicals. In conclusion, we found that BBO can be a good candidate as an effective coupler for diradicals with tunable J values via incorporation of ED and EW groups. This first approach to studying the application of cross-conjugated molecules as couplers also paves the way for new candidates for the development of more effective diradical systems.
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27
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Baranac-Stojanović M. Can Variations of 1
H NMR Chemical Shifts in Benzene Substituted with an Electron-Accepting (NO 2
)/Donating (NH 2
) Group be Explained in Terms of Resonance Effects of Substituents? Chem Asian J 2018; 13:877-881. [DOI: 10.1002/asia.201800137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 02/19/2018] [Indexed: 11/08/2022]
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28
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29
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V. Viesser R, Ducati LC, Tormena CF, Autschbach J. The halogen effect on the 13C NMR chemical shift in substituted benzenes. Phys Chem Chem Phys 2018; 20:11247-11259. [DOI: 10.1039/c8cp01249k] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
X (F, Cl, Br, I) and R (NH2, NO2) group effects on 13C NMR chemical shifts are explained by π and σ orbitals, respectively.
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Affiliation(s)
- Renan V. Viesser
- Institute of Chemistry
- University of Campinas – UNICAMP
- Campinas
- Brazil
| | - Lucas C. Ducati
- Department of Fundamental Chemistry Institute of Chemistry
- University of São Paulo
- São Paulo
- Brazil
| | | | - Jochen Autschbach
- Department of Chemistry
- University at Buffalo
- State University of New York
- Buffalo
- USA
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30
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Larrañaga O, Romero-Nieto C, de Cózar A. Intramolecular SE
Ar Reactions of Phosphorus Compounds: Computational Approach to the Synthesis of π-Extended Heterocycles. Chemistry 2017; 23:17487-17496. [DOI: 10.1002/chem.201703495] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Indexed: 01/04/2023]
Affiliation(s)
- Olatz Larrañaga
- Departamento de Química Orgánica I, Facultad de Química; Universidad del País Vasco, P. K. 1072; 20018 San Sebastián-Donostia Spain
| | - Carlos Romero-Nieto
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Abel de Cózar
- Departamento de Química Orgánica I, Facultad de Química; Universidad del País Vasco, P. K. 1072; 20018 San Sebastián-Donostia Spain
- IKERBASQUE; Basque Foundation for Science; E-48013 Bilbao Spain
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Tao Y, Zou W, Cremer D, Kraka E. Characterizing Chemical Similarity with Vibrational Spectroscopy: New Insights into the Substituent Effects in Monosubstituted Benzenes. J Phys Chem A 2017; 121:8086-8096. [PMID: 28960072 DOI: 10.1021/acs.jpca.7b08298] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A novel approach is presented to assess chemical similarity based the local vibrational mode analysis developed by Konkoli and Cremer. The local mode frequency shifts are introduced as similarity descriptors that are sensitive to any electronic structure change. In this work, 59 different monosubstituted benzenes are compared. For a subset of 43 compounds, for which experimental data was available, the ortho-/para- and meta-directing effect in electrophilic aromatic substitution reactions could be correctly reproduced, proving the robustness of the new similarity index. For the remaining 16 compounds, the directing effect was predicted. The new approach is broadly applicable to all compounds for which either experimental or calculated vibrational frequency information is available.
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Affiliation(s)
- Yunwen Tao
- Department of Chemistry, Southern Methodist University , 3215 Daniel Avenue, Dallas, Texas 75275-0314, United States
| | - Wenli Zou
- Institute of Modern Physics, Northwest University , Xi'an, Shaanxi 710069, People's Republic of China
| | - Dieter Cremer
- Department of Chemistry, Southern Methodist University , 3215 Daniel Avenue, Dallas, Texas 75275-0314, United States
| | - Elfi Kraka
- Department of Chemistry, Southern Methodist University , 3215 Daniel Avenue, Dallas, Texas 75275-0314, United States
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Viesser RV, Ducati LC, Tormena CF, Autschbach J. The unexpected roles of σ and π orbitals in electron donor and acceptor group effects on the 13C NMR chemical shifts in substituted benzenes. Chem Sci 2017; 8:6570-6576. [PMID: 28989684 PMCID: PMC5627350 DOI: 10.1039/c7sc02163a] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 07/20/2017] [Indexed: 11/30/2022] Open
Abstract
NH2 and NO2 group effects on 13C NMR chemical shifts in substituted benzenes are explained by σ- instead of π-orbitals.
Effects of electron-donating (R = NH2) and electron-withdrawing (R = NO2) groups on 13C NMR chemical shifts in R-substituted benzene are investigated by molecular orbital analyses. The 13C shift substituent effect in ortho, meta, and para position is determined by the σ bonding orbitals in the aryl ring. The π orbitals do not explain the substituent effects in the NMR spectrum as conventionally suggested in textbooks. The familiar electron donating and withdrawing effects on the π system by NH2 and NO2 substituents induce changes in the σ orbital framework, and the 13C chemical shifts follow the trends induced in the σ orbitals. There is an implicit dependence of the σ orbital NMR shift contributions on the π framework, via unoccupied π* orbitals, due to the fact that the nuclear shielding is a response property.
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Affiliation(s)
- Renan V Viesser
- Institute of Chemistry , University of Campinas - UNICAMP , P. O. Box 6154 , 13083-970 , Campinas , SP , Brazil .
| | - Lucas C Ducati
- Department of Fundamental Chemistry , Institute of Chemistry , University of São Paulo , Av. Prof. Lineu Prestes, 748 , 05508-000 , São Paulo , SP , Brazil .
| | - Cláudio F Tormena
- Institute of Chemistry , University of Campinas - UNICAMP , P. O. Box 6154 , 13083-970 , Campinas , SP , Brazil .
| | - Jochen Autschbach
- Department of Chemistry , University at Buffalo , State University of New York , Buffalo , NY 14260-3000 , USA .
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Szatylowicz H, Jezuita A, Ejsmont K, Krygowski TM. Substituent Effect on the σ- and π-Electron Structure of the Nitro Group and the Ring in Meta- and Para-Substituted Nitrobenzenes. J Phys Chem A 2017. [DOI: 10.1021/acs.jpca.7b03418] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Halina Szatylowicz
- Faculty
of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Anna Jezuita
- Faculty
of Chemistry, Opole University, Oleska 48, 45-052 Opole, Poland
| | - Krzysztof Ejsmont
- Faculty
of Chemistry, Opole University, Oleska 48, 45-052 Opole, Poland
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Towards physical interpretation of substituent effects: the case of N- and C3-substituted pyrrole derivatives. Struct Chem 2017. [DOI: 10.1007/s11224-017-0938-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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35
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Effect of Intra- and Intermolecular Interactions on the Properties of para-Substituted Nitrobenzene Derivatives. CRYSTALS 2016. [DOI: 10.3390/cryst6030029] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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36
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Zaccaria F, Paragi G, Fonseca Guerra C. The role of alkali metal cations in the stabilization of guanine quadruplexes: why K+ is the best. Phys Chem Chem Phys 2016; 18:20895-904. [DOI: 10.1039/c6cp01030j] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The desolvation and size of monovalent alkali metal ions are of equal importance for the cation affinity of guanine quadruplexes.
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Affiliation(s)
- F. Zaccaria
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling
- Vrije Universiteit Amsterdam
- 1081 HV Amsterdam
- The Netherlands
| | - G. Paragi
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling
- Vrije Universiteit Amsterdam
- 1081 HV Amsterdam
- The Netherlands
- MTA-SZTE Supramolecular and Nanostructured Materials Research Group
| | - C. Fonseca Guerra
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling
- Vrije Universiteit Amsterdam
- 1081 HV Amsterdam
- The Netherlands
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