Experimental and quantum chemical investigation of photochemical properties of a covalently bound bis(styrylquinoline) dyad

• Published in: High energy chemistry 2012-09, Vol.46 (5), p.309-322
• Main Authors: Budyka, M. F., Potashova, N. I., Gavrishova, T. N., Lee, V. M.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Photochemistry; Physical Chemistry
• ISSN: 0018-1439; 1608-3148
• DOI: 10.1134/S0018143912040054

1,3-Bis(4-(2-quinoline-2-vynyl)phenoxy)propane a bis(styrylquinoline) dyad (S3S), has been synthesized and investigated. A comparison of S3S with the model 2-(4-methoxystyryl)quinoline (MeOSQ) has shown that integration of two styrylquinoline fragments (SQ) into the covalently bound dyad affects neither spectral properties nor the initial rate of the transcis photoisomerization reaction, but it results in both a change of the photolysis kinetics in general and the enrichment of the photostationary state in the isomer that has had a higher molar absorption coefficient at the irradiation wavelength. The kinetic scheme of the dyad photolysis including four isomers and eight reactions has been analyzed. The photoisomerization quantum yield of the SQ moiety of the dyad is half that of MeOSQ. Density functional theory (DFT) B3LYP/6–31G* calculation has revealed that the styrylquinoline nuclei in both MeOSQ and the S3S dyad have close geometrical parameters and electron structure. Absorption spectra have been calculated by the TDDFT method in the isolated-molecule approximation for an intermolecular hydrogen bonding-stabilized cluster with the ethanol molecule and in terms of the polarized continuum model (PCM). The absorption spectrum of the trans ( E )-isomer is represented as spectra of two s -conformers, and the TDDFT method for the cis ( Z )-isomer underestimates the energy of the long-wavelength absorption band.