The Novel Dinuclear Complex Tetraaquahexakis(nitrato-O,O ')bis(2,4,6,8-Tetramethyl-2,4,6,8-Tetraazabicyclo[3.3.0]octane-3,7-Dione-O,O ')dipraseodymium(III): Synthesis and Crystal Structure

摘要

A centrosymmetric dinuclear complex, [Pr(C8H14N4O2)(H2O)(2)(NO3)(3)](2) (I), was obtained from praseodymium(III) nitrate and the bicyclic bisurea 2,4,6,8-tetramethyl-2,4,6,8-tetraazabicyclo[3.3.0]octane-3,7-dione (mebicar, Mc) and structurally characterized (CIF file CCDC no. 1435137). The crystals of complex I are triclinic: space group P (1) over bar, a = 9.8967(5), b = 10.3689(5), c = 11.0018(6) angstrom, alpha = 74.650(5)degrees, beta = 68.064(5)degrees, gamma = 67.257(5)degrees, V = 956.22(10) angstrom(3), rho(calcd) = 1.949 g/cm(3), Z = 1. The praseodymium atom is coordinated to two O atoms of two Mc molecules (related by a center of symmetry), three bidentate nitrate anions, and two water molecules. So its coordination polyhedron has ten vertices; the Pr center dot center dot center dot Pr distance is 9.8726(7) angstrom.