Molybdenum complexes with O,N,S donor ligands as models for active sites in oxotransferases and hydroxylases

Eierhoff D, Tung WC, Hammerschmidt A, Krebs B

Abstract

A series of homologous mononuclear dioxomolybdenum complexes were prepared and fully characterized with structurally related thiosemicarbazone ligands supplying a tridentate O,N,S donor set to the central metal atom. The ligands are derived from the prototype 2-hydroxybenzaldehyde-4-triphenylmethylthiosemicarbazone (H2L). Within this series the crystal structures of 11 complex compounds [MoO2(LRn)(dmf)] and [MoO2(LRn)(MeOH)] were determined showing characteristic differences in the gross structural properties of the central metal core. From the variation of substituents in this ligand library the influences of electronic ligand effects on the spectroscopic, electrochemical, and functional properties of these biomimetic model complexes for molybdenum-containing oxotransferases are reported. (C) 2008 Elsevier B. V. All rights reserved.