SOLID-STATE CD-113 NMR-STUDIES ON CADMIUM COMPLEXES WITH GLYCINE, L-ALANINE, AND L-CYSTEINE

Solid-state Cd-113 NMR spectra have been recorded for bis(glycinato)ca dmium(II) hydrate, bis(L-alaninato)cadmium(II) trihydrate, and a 1:2 c omplex of cadmium and L-cysteine; the principal components of the Cd-1 13 shielding tensor have been determined. The spectra show useful addi tional fine structure due to dipolar coupling (both direct and indirec t) between Cd-113 and N-14, which allows the number of nitrogens bonde d to the cadmium center to be determined directly. In the L-alaninate complex, two cadmium resonances are observed which are rationalized as being due to the presence of diastereoisomers within the powdered sam ple. The L-Cysteine complex shows no N-14 coupling, indicating that an y Cd-113-N-14 interactions are weaker than in the other two complexes. An improved X-ray single-crystal structure of the glycinate complex i s also reported.