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Richter WE. Symmetry-Constrained Properties Behave Differently for 2D or 3D Structures under the Same Point Group. J Phys Chem A 2024; 128:4308-4314. [PMID: 38758113 PMCID: PMC11145645 DOI: 10.1021/acs.jpca.4c02167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/06/2024] [Accepted: 05/08/2024] [Indexed: 05/18/2024]
Abstract
In chemistry and physics, two molecules belonging to the same point group are expected to behave similarly regarding various properties, following their character tables. Here, we show that the derivative of the dipole moment with respect to the normal coordinate of vibration might show different symmetry constraints if the molecule is planar, even if these molecules belong to the same point group. Examples of pairs of molecules featuring these conditions are presented. These findings open a new path toward a much deeper understanding of how 2D materials behave so differently compared to 3D materials featuring the very same atoms and arrangements (graphene and graphite, for example); chemists and physicists dealing with 2D materials could benefit from looking more deeply into pure mathematical relations that might be governing 2D systems in a different way when compared to 3D systems. The aid from mathematicians is welcomed.
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Affiliation(s)
- Wagner Eduardo Richter
- Department of Chemistry, Federal
University of Technology − Paraná, Ponta Grossa, Paraná 84.017-220, Brazil
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Richter WE. On the quest for a molecular vibration whose absolute intensity is described solely by fluctuations of atomic dipoles: Can we find it? SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 291:122321. [PMID: 36621029 DOI: 10.1016/j.saa.2023.122321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/30/2022] [Accepted: 01/02/2023] [Indexed: 06/17/2023]
Abstract
The conditions for a molecular vibration to be active in the infrared spectrum while its absolute intensity is described solely by fluctuations of atomic dipoles are presented. A quick recipe of features of such a system is presented, to guide the seek for it. If such a system can be found, it will then be proved that population analyses based solely on a point-charge approximation are unrealistic as they cannot properly describe this intensity, a real, measurable, unambiguous property.
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Affiliation(s)
- Wagner Eduardo Richter
- Department of Chemistry, Federal University of Technology - Paraná, 84.017-220, Ponta Grossa, PR, Brazil.
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Abstract
Generalized atomic polar tensor (GAPT) has turned into a very popular charge model since it was proposed three decades ago. During this period, several works aiming to compare different partition schemes have included it among their tested models. Nonetheless, GAPT exhibits a set of unique features that prevent it from being directly comparable to "standard" partition schemes. We take this opportunity to explore some of these features, mainly related to the need of evaluating multiple geometries and the dynamic character of GAPT, and show how to obtain the static and dynamic parts of GAPT from any static charge model in the literature. We also present a conceptual evaluation of charge models that aims to explain, at least partially, why GAPT and quantum theory of atoms in molecules (QTAIM) charges are strongly correlated with one another, even though they seem to be constructed under very different frameworks. Similar to GAPT, infrared charges (also derived from atomic polar tensors of planar molecules) are also shown to provide an improved interpretation if they are described as a combination of static charges and changing atomic dipoles rather than just experimental static atomic charges.
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Affiliation(s)
- Wagner
E. Richter
- Department
of Chemical Engineering, Federal University
of Technology—Paraná, Ponta Grossa 84017-220, PR, Brazil
| | - Leonardo J. Duarte
- Institute
of Chemistry, State University of Campinas, Campinas 13083-861, SP, Brazil
| | - Roy E. Bruns
- Institute
of Chemistry, State University of Campinas, Campinas 13083-861, SP, Brazil
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Richter WE, Duarte LJ, Vidal LN, Bruns RE. AC/DC Analysis: Broad and Comprehensive Approach to Analyze Infrared Intensities at the Atomic Level. J Phys Chem A 2021; 125:3219-3229. [PMID: 33847496 DOI: 10.1021/acs.jpca.1c01314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We present a complete theoretical protocol to partition infrared intensities into terms owing to individual atoms by two different but related approaches: the atomic contributions (ACs) show how the entire molecular vibrational motion affects the electronic structure of a single atom and the total infrared intensity. On the other hand, the dynamic contributions (DCs) show how the displacement of a single atom alters the electronic structure of the entire molecule and the total intensity. The two analyses are complementary ways of partitioning the same total intensity and conserve most of the features of the total intensity itself. Combined, they are called the AC/DC analysis. These can be further partitioned following the CCTDP (or CCT) models according to the population analysis chosen by the researcher. The main conceptual features of the equations are highlighted, and representative numerical results are shown to support the interpretation of the equations. The results are invariant to rotation and translation and can readily be extended to molecules of any size, shape, or symmetry. Although the AC/DC analysis requires the choice of a charge model, all charge models that correctly reproduce the total molecular dipole moment can be used. A fully automated protocol managed by the Placzek program is made available, free of charge and with input examples.
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Affiliation(s)
- Wagner E Richter
- Department of Chemical Engineering, Federal University of Technology-Paraná, Ponta Grossa, Paraná 81280-340, Brazil
| | - Leonardo J Duarte
- Institute of Chemistry, State University of Campinas, Campinas, São Paulo 13081-970, Brazil
| | - Luciano N Vidal
- Department of Chemistry and Biology, Federal University of Technology-Paraná, Ponta Grossa, Paraná 81280-340, Brazil
| | - Roy E Bruns
- Institute of Chemistry, State University of Campinas, Campinas, São Paulo 13081-970, Brazil
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Richter WE, Duarte LJ, da Silva AF, Bruns RE. Revisiting the negative dipole moment derivatives of HNgX molecules. Theor Chem Acc 2020. [DOI: 10.1007/s00214-020-2582-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Duarte LJ, Silva AF, Richter WE, Bruns RE. Infrared Intensification and Hydrogen Bond Stabilization: Beyond Point Charges. J Phys Chem A 2019; 123:6482-6490. [DOI: 10.1021/acs.jpca.9b03105] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Leonardo J. Duarte
- Instituto de Química, Universidade Estadual de Campinas, CP 6154, Campinas CEP 13083-970, São Paulo, Brazil
| | - Arnaldo F. Silva
- Instituto de Química, Universidade Estadual de Campinas, CP 6154, Campinas CEP 13083-970, São Paulo, Brazil
| | - Wagner E. Richter
- Departamento de Engenharia Química, Universidade Tecnológica Federal do Paraná, Campus Ponta Grossa, Av. Monteiro Lobato s/n, Jardim
Carvalho, Curitiba 84016-210, Brazil
| | - Roy E. Bruns
- Instituto de Química, Universidade Estadual de Campinas, CP 6154, Campinas CEP 13083-970, São Paulo, Brazil
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Duarte LJ, Bruns RE. Atomic Polarizations, Not Charges, Determine CH Out-of-Plane Bending Intensities of Benzene Molecules. J Phys Chem A 2018; 122:9833-9841. [PMID: 30495956 DOI: 10.1021/acs.jpca.8b09141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Infrared gas phase intensities are reported for the first time for 23 CH out-of-plane bending vibrations of eight substituted benzene molecules and naphthalene by integration of bands from the Pacific Northwest National Laboratory (PNNL) spectral library. These experimental values are found to have an rms difference of 8.7 km mol-1 with the B3LYP/6-311++G(d,p) values for intensities ranging from close to zero to 126.7 km mol-1. These intensities are found to have transferable electronic structure parameters, and their square roots are proportional to the amplitudes of the hydrogen atom displacements perpendicular to the benzene ring. Quantum Theory of Atom in Molecules (QTAIM)-Charge-Charge Transfer-Dipolar Polarization models were determined from the B3LYP/6-311++G(d,p) electronic densities. By far, the largest electronic contribution to these intensities is the dipolar polarization of the carbon atom of the displaced CH bond, 0.214 e. Smaller contributions are found for the polarizations of the displaced hydrogen atoms (-0.043 e) and nearest neighbor carbon atoms (-0.052 e), both having directions opposite to that of the carbon atom polarization of the displaced CH bond. The movements of static equilibrium hydrogen charges make the smallest contribution canceling most of the hydrogen polarization changes. In fact, the carbon atomic polarizations alone account for 96.9% of the dipole moment derivative vector norm for the CH out-of-plane bends. The polarization model is also found to be valid for seven CH out-of-plane bending vibrations of N-fused benzene ring molecules (N = 3, 4, 5).
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Affiliation(s)
- Leonardo J Duarte
- Instituto de Química , Universidade Estadual de Campinas , CP 6154, Campinas , SP Brazil , CEP 13.083-970
| | - Roy E Bruns
- Instituto de Química , Universidade Estadual de Campinas , CP 6154, Campinas , SP Brazil , CEP 13.083-970
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Duarte LJ, Richter WE, Silva AF, Bruns RE. Quantum Theory of Atoms in Molecules Charge–Charge Transfer–Dipolar Polarization Classification of Infrared Intensities. J Phys Chem A 2017; 121:8115-8123. [DOI: 10.1021/acs.jpca.7b08031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Leonardo J. Duarte
- Chemistry
Institute, University of Campinas, CP 6154, Campinas, São Paulo 13083-970, Brazil
| | - Wagner E. Richter
- Department
of Chemical Engineering, Technological Federal University of Parana, Ponta Grossa, Paraná 84016-210, Brazil
| | - Arnaldo F. Silva
- Manchester
Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, Great Britain
| | - Roy E. Bruns
- Chemistry
Institute, University of Campinas, CP 6154, Campinas, São Paulo 13083-970, Brazil
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