Solvent-induced Stokes' shift in DCJTB: Experimental and theoretical results

Author(s)

de Sousa, Iran da Luz ^[1] ; Ximenes, Valdecir Farias ^[2] ; de Souza, Aguinaldo Robinson ^[2] ; Morgon, Nelson Henrique ^[1]

Affiliation

^[1] Univ Estadual Campinas, UNICAMP, Inst Chem, Dept Phys Chem, BR-13083861 Campinas, SP - Brazil

^[2] Sao Paulo State Univ, UNESP, Fac Sci, Dept Chem, BR-17033360 Bauru, SP - Brazil

• Document type: Journal article
• Source: Journal of Molecular Structure; v. 1192, p. 186-191, SEP 15 2019.
• Web of Science Citations: 0

Abstract

The solvent-induced Stokes' shift, which describes the response at different solvents (acetonitrile, chloroform, dichloromethane, 1,4-dioxane, N,N-dimethylformamide, ethanol, heptanol, tetrahydrofuran, and toluene) to a sudden change in the charge distribution of excited 4-(Dicyanomethylene)-2-tert-butyl-6- (1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran (DCJTB) molecule, was studied through absorption and emission spectra and TD-DFT calculations; the solvent effect was studied trough the IEF-PCM model. The application of IEF-PCM model with TD-DFT methods to obtain the absorption energies provided excellent match with the experimental results. The results observed, for solvents effects on the positions of maxima absorption and emission between experimental data and theoretical calculations, have average absolute deviations of only 0.03 eV and 0.22 eV, respectively. A systematic error was observed by comparing the theoretical and experimental maxima for the emission energies. However, the application of the Lippert-Mataga and Bilot-Kawski equations to the TD-DFT-simulated Stokes' shifts values resulted in excellent correlation coefficients: Lippert-Mataga, R-2 = 0.9982, Bilot-Kawski, R-2 = 0.9908 and R-2 = 0.9795. (C) 2019 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 15/22338-9 - Study of the interaction between drugs and human serum albumin (HSA) based on computer simulation, DFT and TDDFT, experiments of electronic circular dichroism, ECD, and determination of the bond formation constant
• Grantee: Aguinaldo Robinson de Souza
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/20549-5 - Development and application of fluorescent probes and probes based on circular dichroism for the interaction studies of ligands with protein, characterization of amyloid proteins and determination of enzymatic activity
• Grantee: Valdecir Farias Ximenes
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/50926-0 - INCT 2014: biodiversity and natural products
• Grantee: Vanderlan da Silva Bolzani
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 16/04963-6 - Molecular dynamics of cellulose enzymatic hydrolysis and QM / MM simulations of chemical reactions in biomolecular systems
• Grantee: Gabriel Heerdt
• Support Opportunities: Scholarships in Brazil - Post-Doctoral