Structural study of monoaquabis (pyridine)bis(saccharinato)copper(II), [Cu(H2O)(py)2(sac)2]

The structure of monoaquabis(pyridine)bis(saccharinato)copper(II), [Cu(H2O)(py)(2)(sac)(2)], has been investigated by X-ray diffraction and infrared spectroscopy. The complex crystallizes in the orthorhombic space group I ba2 with the following unit cell parameters: a = 9.4874(7), b = 21.545(1), c = 13.164(1) Angstrom, V= 2690.8(4) Angstrom(3), D-c = 1.491 g cm(-3), Z = 4, R = 0.025, wR = 0.036. The structure consists of individual [Cu(H2O)(py)(2)(sac)(2)] molecules. The copper atom is bonded to two pyridine and two saccharinato nitrogen atoms as well as to the water oxygen atom forming a distorted square pyramid. The copper atom lying on a twofold rotation axis is 0.2209(7) Angstrom above the basis square plane formed by the four nitrogen atoms. The bond distances in the coordination polyhedron are: Cu-N11 2.032(2) Angstrom, Cu-N21 2.040(2) Angstrom, Cu-OW1 2.177(2) Angstrom. The N-Cu-N angles amount 88.67(8) and 89.97(8)degrees as well as 167.36(9) and 167.69(8)degrees while the values of the OW1-Cu-N angles are 96.16(6) and 96.32(6)degrees. The FT infrared spectral features in the region of the OH, OD, CO and SO2 stretching vibrations are discussed and correlated with the data obtained by X-ray diffraction.