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Updated: Sep 19, 2025

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Encasing the paramagnetic copper(II)-ion by the ring-contracted corrin ligand of vitamin B12
Christoph Kieninger1,2, Klaus Wurst3, Daniel Leitner3
1Institute of Organic Chemistry, University of Innsbruck, 6020 Innsbruck, Austria. bernhard.kraeutler@uibk.ac.at.
Abstract:
The d9-Cu(II)-corrin cupribyrate (Cuby) was synthesized in 93% crystalline yield by rapid chelation of Cu2+-ions by the metal-free corrin-ligand of vitamin B12. Single crystals of the EPR-active Cuby allowed for the first X-ray structure determination of a Cu-corrin. SCF-calculations provided insights complementary to the experimental data of Cuby and indicated an out-of-plane displacement of the reduced d10-Cu(I)-ion, consistent with the observed reductive activation of Cuby towards loss of its Cu-center.
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