TERBIUM BINDING IN HIGHLY LUMINESCENT POLYMER COMPLEXES

摘要

Polymer ligands containing a covalently bonded quinolinone fluorophore and COOH (LI)or COONa (L2)binding sites were synthesized by the reaction of high-molecular-weight poly[styrene-alt-(maleic anhydride)]with 7-amino-4-methylquinolin-2(1H)-one and metha-nol and subsequent neutralization.The ligand-to-metal energy transfer and ligand binding properties in a series of [Tb(III)-ligand]complexes were investigated by steady-state and time-resolved luminescence spectroscopy in methanol or deuterated methanol.The intensity of the long-lived terbium(III)ion emission at 490,545,585 and 620 nm was greatly enhanced upon addition of L1 or L2.Based on the differences in luminescence data obtained for [Tb(III)-L1]and [Tb(III)-L2]complexes,a qualitative model for the interaction of ter-bium(III)ion with L1 and L2 is put forward.The experimental luminescence decay curves were double-exponential (tau_1,tua_2)with predominating longer component (rel B_1 >85%)for both [Tb(III)-L1]and [Tb(III)-L2]complexes.About 2.5 or 2 methanol molecules were coordinated to Tb_(3+)in [Tb(III)-Ll]or [Tb(III)-L2]complexes,respectively,whereas ca.6.5 methanol molecules were coordinated to Tb~(3+)in methanol.