Electron spin resonance studies of the solution structure of vanadyl amino acid complexes and mixed ligand complexes of oxalate

✍ Scribed by Craig R. Johnson; Rex E. Shepherd

• Publisher: Elsevier Science
• Year: 1978
• Weight: 1019 KB
• Volume: 8
• Category: Article
• ISSN: 0006-3061
• DOI: 10.1016/s0006-3061(00)80238-0

✦ Synopsis

Esr and electronic spectra of complexes of the general composition VO(AA)p and VO(os)(AA) have been characterized; AA = $Y, his, cys, pro, val, met, asp amino acids. Spectra of the formulation VO(os)(LL) (with LL = imidazole plus monodentate osalate, histamine plus monodentate osalate, histidine, cysteine, 4-imiciazolepropionic acid, mercaptopropionic acid, ethylenediamine and ethanolamine) have been used to deduce a selfconsistent assignment of AL, a ligand donor additivity constant contribution to the observed hyperfine splitting, Aiso-Values of AL are sensitive to inductive effects in the ligand structure. The solution structures and likely coordination geometries of VO(lGs)2, VO(gly)a, and VO(cys)2*-are dis-cussed_ The role of the imidazole moiety as a (r donor and sulfhydryl sulfur as a in acceptor is observed in VO(AX)2 and VO(os)(AA) complexes.