✍ Scribed by Wei-Yin Sun; Takafumi Ueno; Norikazu Ueyama; Akira Nakamura
No coin nor oath required. For personal study only.
Isotropically shifted ^19^F NMR signals were observed for novel mononuclear Co(II) complexes, (Et~4~N)~2~[Co(Z‐Cys‐Pro‐Leu‐Cys‐Gly‐X)~2~] (Z = benzyloxycarbonyl, X = NHC~6~H~4~‐p = F, NHC~6~H~4~‐m‐F and NHCH~2~CH~2~C~6~H~4~‐p‐F). Such isotropically shifted signals show very short ^19^F spin‐lattice relaxation times (T~1~) 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 ^19^F T~1~ values in the range 1600–3200 ms. The observed ^19^F NMR isotropic shifts and short ^19^F T~1~ 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.
📜 SIMILAR VOLUMES
## Abstract An Fe(II) complex with Z‐Ala‐CysProLeuCysGlyNHC~6~H~4~__m__F (Z = benzoxylcarbonyl) having an invariant bidentate peptide ligand, CysKYCys, in rubredoxins was synthesized. The contact‐shifted ^1^H, ^2^H and ^19^F NMR signals of (Et~4~N)~2~[Fe(ZAlacysProLeucysGlyNHC~6~
## Abstract We report here the generation of gas‐phase complexes containing Pd(II), a ligand (deprotonated alanine, A^−^), and/or N‐terminus derivatized peptides containing histidine as one of the amino acids. The species were produced by electrospray ionization, and their gas‐phase reactions were
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