A square-planar di-N-carboxamido, dithiolato–cobalt(III) complex related to nitrile hydratase metallic site. Addition of axial ligands and EXAFS study of the derived dicyano and diisocyanido complexes
A square-planar cobalt(III) complex with a N2S2 di-N-carboxamido di-thiolato tetradentate ligand, mimics the metal core of the cobalt containing nitrile hydratases. It forms hexacoordinated complexes only upon addition of ligands like cyanide or isocyanides. An EXAFS analysis confirmed that two axial ligands get bound, and lead to a significant increase of the bond lengths between the cobalt(III) and the equatorial ligands. Whereas the planar complex is stable in the presence of air or hydrogen peroxide, its hexacoordinated derivatives with strong sigma -donor axial ligands undergo an oxygenation of the equatorial thiolate ligands. (C) 2001 Elsevier Science B.V. All rights reserved.
SYNTHESIS OF POLYDENTATE LIGANDS CONTAINING AMIDES AND THIOLS FOR BIOMIMETIC METAL COMPLEXES
作者:Laurent Heinrich、Jean-Claude Chottard、Yun Li
DOI:10.1081/scc-100104041
日期:2001.1
Three pentadentate “N2S3” and one tetradentate “N2S2” new ligands with “N” = CONH and “S” = SH have been synthesized. The key step is the direct diamide formation from the malonyl diester and the amines in the presence of trimethylaluminum.