Crystal structure of copper(II) (+)-(S,S ')-alpha, alpha '-(9-oxo-1,5-diphenyl-3,7-diazabicyclo[3.3.1]non-3,7-ylene)dipropionate dihydrate

This paper reports on an X-ray diffraction study of the crystal and molecul ar structure of the dihydrate of the copper complex (II) of recently define d (+)-S,S')-alpha, alpha'-(9-oxo-1,5-diphenyl-3,7-diazabi-cyclo[3.3.1]non-3 ,7-ylene)dipropionic acid (I). Crystals II are orthorhombic with unit cell dimensions a=9.169(2), b=17.591(2), c=29.410(Angstrom) Z=8 (C25H26CuN2O5. 2 H(2)O), space group P2(1)2(1)2(1). Structure II was solved by direct method s. Full-matrix least-squares anisotropic refinement converged to R = 0.033 for all 4523 measured independent reflections (CAD-4 automatic diffractomet er, lambda CuKalpha). The structure of II contains two symmetrically indepe ndent complex molecules, II and II' which are similar in structure and link ed into a dimer by Cu-O' coordination bond. In both molecules, the Cu atom is pentacoordinated; its polyhedron is a distorted square pyramid with a ba se of two N atoms and two carboxylate O atoms and with an apex at the carbo xylate O atom of the neighboring molecule II' (in molecule II) or at the O atom of the water molecule (in molecule II'). The covalent bicyclic framewo rks of II and II' each consisting of two fused 6-membered rings have a chai r-chair conformation, which is also typical for the noncoordinated molecule s of compounds I.