Your browser doesn't support javascript.
2,3-(Dibenzimidazol-2-yl)quinoxalines: Unexpected Dynamical Effect on Steady-State Electronic Absorption Spectra.
J Phys Chem B ; 123(26): 5514-5523, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31192599
We report on the electronic absorption spectra, conformational behavior, and intra- and intermolecular hydrogen bonds of 2,3-(dibenzimidazol-2-yl)-quinoxaline (DBIQ). The experimentally found strong solvent dependence of the absorption spectra of DBIQ solutions cannot be assigned to electronic excitations of the equilibrium ground-state DBIQ structure. Extended consideration including the nonequilibrium structures within the framework of ab initio molecular dynamics (MD) revealed the importance of torsion molecular motions not covered by the static case. The strong impact of solute-solvent hydrogen bonding on stabilization of these nonequilibrium structures and on conformational composition of DBIQ was demonstrated. A presence of twisted nonplanar geometries along the whole MD trajectory was shown to drastically influence not only energies but also characters of electronic excitations, resulting in a change of local π-π* character in a solution of 1,2-dichloroethane to charge-transfer character in polar dimethylsulfoxide.





Texto completo: Disponível Coleções: Bases de dados internacionais Base de dados: MEDLINE Idioma: Inglês Revista: J Phys Chem B Assunto da revista: Química Ano de publicação: 2019 Tipo de documento: Artigo País de afiliação: Federação Russa