Crystal Structure and Spectroscopic Studies of a Dimeric Europium( III) similar to- Diketonate Complex Containing [ 3-( 2-Pyridyl)-1-pyrazolyl] acetate

Abstract

The homodinuclear europium(III) -diketonate complex [Eu-2(bta)(4)(pypzCH(2)COO)(2)] (1) {bta = 1-benzoyl-3,3,3-trifluoroacetonate, pypzCH(2)COO = [3-(2-pyridyl)-1-pyrazolyl]acetate} was isolated after recrystallization of the crude product obtained from the reaction of [Eu(bta)(3)(H2O)(2)] with one equivalent of the ligand phenyl[3-(2-pyridyl)-1-pyrazolyl]acetate (pypzCH(2)CO(2)C(6)H(5)). A single-crystal X-ray diffraction study confirmed that during the recrystallization the hydrolysis of the ester group in pypzCH(2)CO(2)C(6)H(5) took place to give pypzCH(2)COO(-), which culminated in the crystallization of dinuclear complex 1 in which each Eu3+ ion is coordinated to two O,O-chelated bta(-) groups and one N,N-chelated pyrazolylpyridine ligand, and the two metal centers are linked by tridentate chelating-bridging ((2)-(2),(1)) carboxylate groups. The luminescence properties of 1 were investigated by steady-state photoluminescence (PL), PL excitation, and time-resolved PL.