Complexes of lanthanide picrates and bis(pentamethylene)urea. Structure ofthe Pr compound

Complexes of lanthanide picrates with bis(pentamethylene)urea (BPMU) with c omposition Ln(pic)(3) . 3(BPMU) (pic = picrate; Ln = La-Er,Y) were synthesi zed and characterized by CHN analyses, EDTA titrations of lanthanide ions, infrared absorption spectroscopy, ii-ray powder patterns, absorption spectr a of the Nd and Er compounds and emission spectra of the Sm and Eu compound s. X-ray single-crystal analysis of the Pr compound was carried out and sho wed that the coordination polyhedron is a distorted monocapped square antip rism with C-2v symmetry. This compound presents yellow crystals with symmet ry of the monoclinic space group P2(1)/c with a = 12.906(4) Angstrom, b = 2 1.80(1) Angstrom, c = 22.96(1) Angstrom, beta = 105.46(3)degrees.