Infrared intensity analysis of hydroxyl stretching modes in carboxylic acid dimers by means of the charge-charge flux-dipole flux model

Autor(es)

da Silva, Natieli Alves ^[1] ; Andrade Haiduke, Roberto Luiz ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, Dept Quim & Fis Mol, Av Trabalhador Sao Carlense 400, CP 780, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Computational Chemistry; v. 40, n. 28 JULY 2019.
• Citações Web of Science: 0

Resumo

The Charge-Charge Flux-Dipole Flux (CCFDF) model in terms of multipoles from the quantum theory of atoms in molecules (QTAIM) was used to investigate the variations in infrared intensities of hydroxyl (O Symbol of the Klingon Empire H) stretching modes during the dimerization of carboxylic acids. The hydrogen bond formation in these systems results into bathochromic shifts of vibrational frequencies for all the O Symbol of the Klingon Empire H stretching modes along with huge infrared intensity increments for some of them. These bands become more intense on dimerization due mainly to changes in the cross-term contribution between charge and charge flux. In addition, interaction energies for the pair of atoms directly involved in individual hydrogen bonds (O horizontal ellipsis H) are linearly correlated to electron densities at their bond critical points (BCPs). Therefore, the hydrogen bonds between the carbonyl group (C(sic)O) of acetic acid and the hydroxyl group of halogenated monomers show the largest electron density values at their BCPs. The formation of these intermolecular interactions is also accompanied by ionic character enhancements of O Symbol of the Klingon Empire H bonds and electron density decrements at their BCPs. We finally noticed that the hydrogen atom belonging to the hydroxyl group loses electronic charge, while the oxygen from the C(sic)O end becomes more negatively charged during dimerization. (c) 2019 Wiley Periodicals, Inc. (AU)

• Processo FAPESP: 14/23714-1 - Cálculos relativísticos de estrutura eletrônica para avaliação de novos conjuntos de funções de base sem prolapso variacional
• Beneficiário: Roberto Luiz Andrade Haiduke
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 10/18743-1 - Uso de multipolos da teoria quântica de átomos em moléculas e estudos cinéticos em sistemas encontrados no meio interestelar
• Beneficiário: Roberto Luiz Andrade Haiduke
• Modalidade de apoio: Auxílio à Pesquisa - Regular