Photoisomerization and Energy Transfer in an Unsymmetrical Biphotochromic Dyad with a Longitudinal Shift of Photochromes—Derivatives of 3-Styrylbenzo[f]quinoline and Oxymethylene Bridging Group

Autor: T. N. Gavrishova, Mikhayl F. Budyka, V. M. Li, S. A. Dozmorov
Rok vydání: 2021
Předmět:
Zdroj: High Energy Chemistry. 55:23-36
ISSN: 1608-3148
0018-1439
DOI: 10.1134/s0018143921010094
Popis: An unsymmetrical biphotochromic dyad D2 containing derivatives of 3-styrylbenzo[f]quinoline (SBQ) has been synthesized and studied. The structure of the dyad has been so designed as to prevent the [2 + 2] photocycloaddition reaction, which has been achieved by using an oxymethylene bridging group, two different SBQ photochromes, and longitudinal displacement of them relative to one another. Under the action of light, a photoisomerization reaction and energy transfer between two SBQ photochromes with an efficiency of 99% have been detected in the dyad, leading to quenching of the SBQ donor and sensitization of the SBQ acceptor. Long-wavelength fluorescence, which could be attributed to an exciplex, has not been observed. Upon long-term irradiation of the dyad, a side reaction has been observed, presumably photocyclization of the SBQ acceptor. Quantum chemical calculations of the relative stability of the dyad conformers have been performed using density functional theory (DFT). A comparison of the calculated and experimental data has shown that the functionals B3LYP-GD3 and M06-2X allowing for the dispersion corrections, with the 6-31G* basis set, possibly overestimate the stability of the conformers of the dyad with the π-stacking interaction of the SBQ photochromes, which can be precursors of exciplexes.
Databáze: OpenAIRE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje