Structure of Bis(L-Alaninato) Zinc(II) and Single Crystal EPR Spectra of Cu(II) Impurities

S. D. DALOSTO; R. CALVO; O. E. PIRO; E. E. CASTELLANO

JOURNAL OF INORGANIC BIOCHEMISTRY

Elsevier

Año: 1999 vol. 73 p. 151 - 155

0162-0134

Abstract The title compound (CHCO2CH3NH2)2Zn(II), abbreviated as Zn(L-alanine)2, crystallizes in the monoclinic space group P2j with a = 8.637 (1), b = 5.334 (1), c = 9.581 (1) , beta = 90.36 (1)º, and Z = 2. The structure was solved employing 1206 independent X-ray reflections with I > 2sigma(I) by Patterson and Fourier methods and refined by full-matrix least squares to R I = 0.031. The Zn (II) ion is fivefold coordinated with two bidentate amino acid ligands and a carboxylate oxygen of another symmetry-related alaninate ion. EPR spectra of copper impurities were measured with the magnetic field in three orthogonal planes of a single crystal sample. The g and hyperfine coupling tensors were evaluated from the spectra. These values are discussed in terms of the structure of Zn(L-alanine)2 and compared with those reported for the quasi-isomorphic compound Cu(L-alanine)2. The distortion of the Zn site when occupied by copper(II) impurities is analyzed.