Synthesis and spectral properties of novel fluorescent poly(oxyethylene phosphate) tris(beta-diketonate) europium (III) complexes.

Novel poly(oxyethylene phosphate) tris(beta-diketonate) europium (III) complexes have been synthesized by an improved procedure using the Atherton-Todd reaction conditions. N-ethyldiisopropylamine has been used as a mild base and propylene oxide as an acid scavenger in order to obtain poly(oxyethylene phosphate) in yield and purity higher than those achieved by conventional methods. The compounds have been characterized by 1H, 13C, and 31P NMR and FTIR techniques. Their absorption, fluorescent excitation and emission spectra of chloroform and abs. ethanol solutions have been recorded and studied. The luminescent quantum yields and decay times have been determined and a dependence on the length of the oxyethylene spacer between phosphate groups has been established. The new polymer complexes are water soluble and have increased luminescence decay time in comparison with corresponding ternary complexes.