些V/S,V/Fe/S和Mn/O簇合物溶液化学行为的NMR研究

报道我们对某些V/S,V/Fe/S和Mn/O簇合物溶液化学的核磁研究.(Et₄N)V₄S₄(C₄H₈NCS₂)₆](1)的¹H NMR谱包含三个宽峰,δ4.77,5.17和7.57,分别归属为端基与桥基配体的α-H.游离配体信号的出现表明了溶液中发生配体与溶剂分子的交换反应.对一系列VFe₃S₄(R₂ NCS₂)₄]^-簇合物(R₂=OC₄H₈(2),Et₂(3))进行了¹H NMR表征.钒与三个铁中心的配体氢谱被分别归属.对NMR谱的时间跟踪发现位于δ19.6(2)以及δ34.2(3)的信号逐渐增长,这意味着新物种形成.合成反应的动态NMR跟踪指认了新物种为Fe₄S₄(R₂ NCS₂)₄.提出了溶液中簇骼金属原子交换机理.包含H₂O和NO₃配体的单核锰bpy配合物(4)的氢谱指示出这些单齿配体的可交换性.它促使配合物4成为含有两个单核Mn分子的包容化合物.

STUDY ON SOLUTION CHEMISTRY OF SOME V/S,V/Fe/S AND Mn/O CLUSTER COMPOUNDSBY NMR SPECTROSCOPY

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 ofV₄S₄(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 ofVFe₃S₄(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.