The nature of interactions and UV-induced response within α-zirconium phosphate intercalation compounds with azobenzenes

Abstract

Azobenzenes immobilization on a solid support enables the usage of their trans-cis isomerization ability for preparation of functional materials. The behavior of azobenzenes in the interlayer space of α-zirconium phosphate (ZrP) upon the UV-Vis irradiation was investigated. Two experimental approacheswere performed: (1) co-intercalation of benzylalkylammoniumsurfactants and azobenzene in the interlayers of ZrP (ZBCnA), and (2) intercalation of p-aminoazobenzene (ZpA). The materials were characterized with XRD, FTIR, UV-Vis, CHN analysis, and the molecular modeling. The molecules in ZBCnA samples were sparsely packed and held by weak hydrophobic interactions. Conversely, themolecules in ZpA samplewere stronglyH-bonded to the ZrP,well-ordered, and densely packed. These structural features determined the samples' photoresponsive behavior. Low density of molecules in the ZBCnA samples, allowed the effective, fast, and reversible isomerization of azobenzene. Whereas the ZpA sample did not react to the UV irradiation because of the steric hindrance of tightly packed molecules.