The Dependence of Benzo-15-Crown-5 Ether-Containing Oligo Paraphenylene Vinylene (CE-OPV) Emission Upon Complexation with Metal Ions in Solution

Abstract

The effects of metal salts (NaCl, CaCl 2·2H 2O, EuCl 3·6H 2O and Eu(OAc) 3) on the steady state and time resolved fluorescence behaviour of poly(para phenylene vinylene) oligomers containing benzo15-crown-5 ether units (CE-OPV) have been investigated. The presence of EuCl 3 causes a significant (8-9 fold) increase in the fluorescence emission intensity of the OPV segments, as compared to pure CE-OPV, in 99:1 methanol/chloroform solution and a small (∼9 nm) red shift in the emission maximum. The presence of Na +or Ca 2+ results in less marked increases in fluorescence intensity compared to Eu 3+. In the presence of Eu 3+ and Na +, the fluorescence intensity increases approximately linearly wi..