Photo- and ionochromic properties of aza crown derivatives of enamino 1-benzothiophen-2-ones.

Minkin, V.; Bren', V.; Dubonosov, A.; Tikhomirova, K.; Shepelenko, E.

2-( N-Acyl- N-arylaminomethylidene)-1-benzothiophen-3(2 H)-ones exhibit photochromic properties due to photoinitiated Z/ E isomerization with respect to the exocyclic C=C bond and subsequent fast thermal N→O migration of the acyl group and syn→ anti isomerization of the N-acyl isomer. Introduction of a 15-azacrown-5 substituent into the para position of the aryl group reduces the quantum yield of the N→O rearrangement down to zero. By contrast, under irradiation with a mercury lamp, crown ether complexes with alkaline earth cations are converted almost completely into the O-acyl isomers which, unlike their N-acyl analogs, show no fluorescence. The highest quantum yields for the N→O acyl group migration are observed for the calcium complexes. The obtained compounds constitute a new class of acylotropic molecular switches operating under photoinitiation exclusively in the presence of alkaline earth cations.

THERMAL analysis; ISOMERIZATION; ISOMERASES; ALKALINE batteries; ALKALINE protease; PROTEOLYTIC enzymes

Russian Journal of Organic Chemistry, 2014, Vol 50, Issue 4, p540

1070-4280

Academic Journal

10.1134/S1070428014040162