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Updated: Oct 3, 2026

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
The Synthesis, NMR Spectroscopy, and X-ray Structure of a New Rhenium N(2)S(2) Chelate Complex
R. A. Bell1, B. E. McCarry, J. F. Valliant
1Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1, Canada.
Abstract:
A new chelate, mercaptoacetyl-L-histidinyl-S-benzyl-L-cysteine methyl ester was synthesized by standard peptide coupling techniques and reacted with ReOCl(3)(PPh(3))(2) to give two diastereomers, 7a and 7b. The two isomers were separated by reversed-phase HPLC and characterized by NMR spectroscopy and electrospray mass spectrometry. An X-ray structure of one isomer, 7a, confirmed that the chelated complex was analogous to other Re-N(2)S(2) compounds in that it formed a square pyramidal complex where the four donor atoms were the base of the pyramid and the oxygen attached to the rhenium was at the apex. The S-benzyl group, as expected, was cleaved during the formation of 7, and the resulting complex was a zwitterion where the rhenium was formally -1 and the counterion was the protonated imidazole ring.
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