Synthesis, luminescence studies and crystal structures of two europium(II) hydrotris(pyrazol-1-yl)borate complexes:: Eu(HBpz3)2•2DPSO and Eu(HBpz3)2•2BPMU

Europium(II) hydrotris(pyrazol-1-yl)borate complexes, Eu(HBpz(3))(2)L-2 (L = diphenylsulfoxide (1) and bis(pentamethylene)urea (2)), have been synthesized. Characterization of 1 and 2 by infrared absorption spectroscopy points to coordination of the neutral ligands through the sulfoxide and carbonyl oxygens, respectively. This was corroborated by X-ray diffraction analysis. In both compounds the metal centre is eight-coordinate by way of the six nitrogens of the two tridentate pyrazolyl ligands and the oxygen atoms of the diphenylsulfoxide or bis(pentamethylene) urea ligands, in a square antiprismatic configuration. Both complexes are luminescent at 77 K and display emission bands with maxima at 610 and 632 nm for 1 and 2, respectively. (C) 2000 Elsevier Science Ltd. All rights reserved.