No abstract

Cysteine-containing peptide (pep) complexes of Pd(II) have been synthesized and their structures in organic solvents such as dimethyl sulfoxide (Me2SO) and N,N-dimethylformamide (DMF) were examined by use of 1H-, 13CNMR, visible, and CD spectroscopies. In all cases of the Pd(II) complexes, only the thiolato group of the peptides coordinates to the metal. Upon mixing [PdCl4]2− and the peptide, a trans(S) isomer [PdCl2(pep)2]2− immediately forms, which gradually isomerizes to the cis(S) isomer at 20 °C in DMF. The reactivity of Pd(II)–S bonds in these complexes was examined by addition of 2,2′-bipyridyl, 2-mercaptoethanol, or 3,4-toluenedithiol.

The influence of the mutual interaction between the molecules of different components in the sample on the retention volume of each component has been discussed from the standpoint of a strictly regular solution. The retention volume of each component in the mixture either increases or decreases, compared with that in the single component samples, according to the kinds of sample and of stationary phase liquid.