Enhancement of photoinduced intramolecular cross-cycloaddition of α-(9-anthryl)-ω-(1-naphthoyl) end-labeled poly(ethylene glycol) via lipophobic interactions and complexation with metal cations
作者:Ming Xu、Li-Zhu Wu、Li-Ping Zhang、Chen-Ho Tung
DOI:10.1016/s0040-4039(01)02002-0
日期:2001.12
The fluorescence spectra and photocycloadditions of poly(ethylene glycol) labeled at the chain termini with one 9-anthryl and one 1-naphthoyl group (N-P-n-A) both in non-polar and polar solvents in the presence of alkali-metal cations have been investigated. Lipophobic interactions in non-polar solvents and complexation of the polyether with cations in polar solvents force the two terminal groups of N-P-n-A into proximity, and irradiation of the solutions produces intramolecular photocyclomers to the exclusion of intermolecular products. (C) 2001 Published by Elsevier Science Ltd.