PUB - Publikationen an der Universität Bielefeld

The synthesis of a covalently bonded new photoresponsive molecular capsule formed from two resorcin [4]arene cavitands by fourfold ether linkages using azobenzene subunits is reported. The new molecular capsule undergoes trans to cis isomerization upon irradiation with 365 nm light and can be reversed back from cis to trans form by means of exposure to visible light (530 nm) in benzene solution. The photo-switchable behaviour was also investigated by H-1 NMR spectroscopy which further substantiated the UV-vis experiment. The quantum chemical calculations both at PM6 as well as at the DFT (B97-D) level of approximation for various stereoisomers starting from all-trans to all-cis indicated an increasing flexibility of these molecular capsules. (C) 2016 Elsevier B.V. All rights reserved.