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

Abstract

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 bat2 with the following unit cell parameters: a = 9.4874(7), b = 21.545(1), c = 13.164(1) Å, V= 2690.8(4) ų, 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) Å above the basis square plane formed by the four nitrogen atoms. The bond distances in the coordination polyhedron are: Cu-N11 2.032(2) Å, Cu-N21 2.040(2) Å, Cu-OW1 2.177(2) Å. The N-Cu-N angles amount 88.67(8)° and 89.97(8)° as well as 167.36(9) and 167.69(8)°, while the values of the OW1-Cu-N angles are 96.16(6)° and 96.32(6)°. 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.