Redox-Induced Ligand Reorganization and Helicity Inversion in Copper Complexes of N,N-Dialkylmethionine Derivatives
摘要:
N, N'-Dipicolyl, bis(stilbylvinylpyridylmethyl), and diquinaldyl methionine derivatives form stable Cu-II complexes with metal ligation by three nitrogen atoms and the carboxylate. One-electron reduction results in the exchange of carboxylate for sulfide in the complexes. This ligand reorganization is accompanied by inversion of the helical orientation of the two arms containing nitrogen heterocycles, resulting in nearly mirror image circular dichroism spectra. This paper provides details for the synthesis of these complexes and the evidence for the remarkable stereochemical interconversion that accompanies the reduction reaction. Detailed analysis of the electronic spectra of the ligands and metal complexes is provided along with X-ray crystallographic structures of Cu-II and Zn-II complexes of the N, N'-dipicolylmethionine complexes.
Redox-Induced Ligand Reorganization and Helicity Inversion in Copper Complexes of <i>N</i>,<i>N</i>-Dialkylmethionine Derivatives
作者:Steffen Zahn、Debasis Das、James W. Canary
DOI:10.1021/ic060660q
日期:2006.7.1
N, N'-Dipicolyl, bis(stilbylvinylpyridylmethyl), and diquinaldyl methionine derivatives form stable Cu-II complexes with metal ligation by three nitrogen atoms and the carboxylate. One-electron reduction results in the exchange of carboxylate for sulfide in the complexes. This ligand reorganization is accompanied by inversion of the helical orientation of the two arms containing nitrogen heterocycles, resulting in nearly mirror image circular dichroism spectra. This paper provides details for the synthesis of these complexes and the evidence for the remarkable stereochemical interconversion that accompanies the reduction reaction. Detailed analysis of the electronic spectra of the ligands and metal complexes is provided along with X-ray crystallographic structures of Cu-II and Zn-II complexes of the N, N'-dipicolylmethionine complexes.
Absolute Configurations of <i>N</i>,<i>N</i>-Dialkyl α-Amino Acids and β-Amino Alcohols from Exciton-Coupled Circular Dichroism Spectra of Cu(II) Complexes
作者:Steffen Zahn、James W. Canary
DOI:10.1021/ol990715a
日期:1999.9.1
[formula: see text] A circular dichroism technique has been applied to the absoluteconfigurational assignment of acyclic alpha-amino acids and beta-amino alcohols with single stereogenic centers via a one-step derivitization procedure requiring microgram quantities of material. Metal ions fix the geometrical relationship of two chromophores, affording CD spectra that agree with theory on the basis