Crystal structure and vibrational spectra of polyamine-copper(II) complexes

The structures of [Cu(en)(H2O)(2)]SO4 (I), [Cu(en)(2)](NO3)(2) (II) and [Cu(trien)I]I (III) have been determined by single crystal X-ray diffraction. Complex I is monoclinic, space group C2/c, with unit cell parameters a = 7.232(1), b = 11.725(2), c = 9.768(1), beta = 105.50(1)degrees, and Z = 4. Complex II is also monoclinic, space group P2(1)/a, with a = 7.978(2), b = 9.982(4), 8.218(3), beta = 111.11(2)degrees, and Z = 2. Complex III is orthorhombic, space group P2(1)2(1)2(1), with a = 8.098(1), b = 11.902(1), c = 13.682(2), and Z = 4. The structures were solved by direct methods and refined by full-matrix least-squares to final R values of 0.031, 0.043 and 0.036 for complexes I, II, and III, respectively. Complexes I and II show an octahedral coordination geometry. Complex III shows a square pyramidal coordination geometry. Complex I forms infinite monodimensional chains where the SO42- ions acts as a bridge between two neighboring en molecules. The vibrational spectra of these complexes agree well with their crystal structures. Structure and stability of seven other related Cu(II) complexes of (trien), (dien)(2), (en)(2) and (en) are inferred in this study.