Structure of the copper(II) complex of (S-.beta.-(2-pyridylethyl)-L-cysteine (original) (raw)

The structure of the copper(I1) 1 : 2 complex of (S)-p-(2-pyridylethyI)-~-cysteine (2-PEC), 3, has been ascertained by nmr, esr, mid-and far-infrared, and Raman spectroscopy, as well as circular dichroism (CD). The results in solution (nmr, esr, CD) show that the 2:l complex, 3, involves coordination of copper(I1) to the amino and carboxylate groups of 2-PEC in glycine-like fashion. The solid 2: 1 complex, 3, can be isolated and mid-and far-infrared as well as CD data confirm that 3, in the solid state, is also coordinating in glycine-like fashion. The esr spectra on frozen solutions of 3 indicate that 3 has approximately square-planar D z h symmetry and that tentatively the configuration of the amino and the carboxylate groups around the copper(I1) ion is trans.