ISSN:
0749-1581
Keywords:
19F NMR
;
isotropic shift
;
Co(II)-cysteine-thiolate complexes
;
19F T1
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Isotropically shifted 19F NMR signals were observed for novel mononuclear Co(II) complexes, (Et4N)2[Co(Z-Cys-Pro-Leu-Cys-Gly-X)2] (Z = benzyloxycarbonyl, X = NHC6H4-p = F, NHC6H4-m-F and NHCH2CH2C6H4-p-F). Such isotropically shifted signals show very short 19F spin-lattice relaxation times (T1) in the range 20-150 ms compared with the corresponding SH-free peptide ligands, Z-Cys(SH)-Pro-Leu-Cys(SH)-Gly-X, which revealed signals with 19F T1 values in the range 1600-3200 ms. The observed 19F NMR isotropic shifts and short 19F T1 values in the Co(II)-cysteine-peptide complexes are ascribed to the formation of NH - S hydrogen bonds and the presence of interactions of aromatic groups with the sulphur atom of the coordinated cysteine residue.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260330304
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