Research Information System
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES, vol.56, no.11, pp.1123-1128, 2001 (SCI-Expanded)
[Cu-3 (L)(3)].3(ClO4) (LH = 1,3-diaminopropan-2-ol) was synthesized and its crystal structure determined. It crystallizes in the triclinic space group P (1) over bar with a = 10.504(2), b = 10.856(2), c = 12.519(2) Angstrom, alpha = 74.41(1), beta = 70.60(1), gamma = 63.60(1)degrees, V = 1193.6(3) Angstrom (3), Z = 2. The structure consists of trimeric [Cu-3(L)(3)](+3) units and three perchlorate anions in the asymmetric unit. In the compound three copper(II) ions are linked by 1,3-diamino-2-propanol molecules in such a way that an almost equilateral triangle is formed. The coordination spheres of the three copper(II) ions are slightly different from each other. The coordination geometry of Cu1 is a distorted square pyramid, and that of Cu2 is almost square planar while that of Cu3 is tetrahedrally distorted square planar. The copper(II) centers are separated by average 3.481(2) Angstrom and antiferromagnetically coupled (-J = 100 cm(-1)), which follows from temperature-dependent magnetic susceptibility measurements in the temperature range 4.4 to 299 K. The average Cu-O-Cu angle is 128.1(1)degrees in the super-exchange pathway. As the temperature is increased, the magnetic moment rises from 1.41 mu (B) at 4.4 K to 2.22 mu (B) at 299 K. In the chi (T) curve no characteristic maximum was observed. The magnetic super-exchange interaction for the title compound is due to the effective overlap of the magnetic orbitals (d(x2-y2)) With orbitals of bridging alkoxide oxygen atoms.