关键词: 核磁共振, 溶液化学, 金属簇合物

Abstract: This paper reports some interesting prollemsion solution chemistry of V/S,V/Fe/S and Mn/O cluster compounds by their NMR studies.
The ¹H NMR spectrum of[V₄S₄(C₄H₈NCS₂)₆]^- shows three broad resonances at 4.77, 5.17 and 7.57ppm which were assigned to the α-H of C₄H₈NCS₂ ligands in terminal and bridged ligations. The signals of free C₄H₈NCS₂ are also observed, which occur from an exchange between the R₂NCS₂ ligand and the solvent molecules.
The ¹H NMR spectra of a series of[VFe₃S₄(R₂NCS₂)₄]^- were determined in DMSO-d₆, exhibiting two sets of signals assigned to the α-H of the R₂NCS₂ ligands linking to V and Fe sites, respectively. A broad peak centered at 19.6ppm for complex 2 or at 33ppm for 3 was found to grow up with time going on, indicating the formation of Fe₄S₄(R₂NCS₂)₄(R₂=OC₄H₈,Et₂). This assignment was identified by a dynamic tracing ¹H NMR experiment in which Fe₄S₄(R₂NCS₂)₄ was synthesized and its ¹H NMR signals were monitored. A possible metal exchange accompanying the formation of Fe₄S₄(R₂NCS₂)₄ in DMSO solution was suggested.
The ¹H NMR spectrum of mononuclear Mn bpy complex 4 containing H₂O and NO₃ ligands was determined, indicating the exchangeability of these monodentate ligands, which makes 4 become an inclusion compound including two mononuclear Mn molecules.

Key words: NMR, Solution chemistry, Metallic cluster compound