Reversible trans/cis photoisomerization in Langmuir-Blodgett multilayers from polyfunctional azobenzenes

Four novel, amphiphilic, N-acylaminoazobenzene derivatives containing a sulfonyl group and a β-alanine moiety were synthesized and their mono- and multilayers were prepared by the Langmuir-Blodgett (LB) technique. The opto-physical properties of the LB multilayers were investigated. Some relationship between the chemical structure of the azobenzenes and photosensitivity of their LB multilayers has been found. Reversible trans/cis photoisomerization was observed on alternate irradiation with ultraviolet and visible light of LB multilayers from azobenzenes modified by the introduction of a second aliphatic chain in the N-acylamino fragment as well as by introduction of the bulky N,N′-dicyclohexyl urea moiety.