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

The homodinuclear europium(III) β‐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 (H 2 O) 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 Eu 3+ 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 (μ 2 ‐η 2 ,η 1 ) carboxylate groups. The luminescence properties of 1 were investigated by steady‐state photoluminescence (PL), PL excitation, and time‐resolved PL.