Electon-Deficient d- and f-Transition Metal Complexes with Sulfur Ligands

(1)我们从Li_2S_x(x=L，2，4)与Cp^*Tacl_4(Cp^*=eta^5-C_5Me_5)的反应中分离出杂色硫化物。这些硫化物络合物的一个共同点是它们含有与硫强烈结合的锂离子。通过利用这些锂的优势，我们找到了一条由一个共同的Cp^*TaS_3单元组成的异核团簇的新途径。例如，[Cp^*TaS_3Li_2(THF)_2]_2与[RhCl(Cod)]_2反应生成了TarH_2三核配合物(Cp^*TaS_3)[Rh(Cod)]_2。该结构在溶液中不是刚性的，其流动行为由COD配体中的烯烃质子产生的^1H-核磁共振信号监测。我们推测，两个Rh(Cod)片段通过三坐标中间体迁移到Tas^3单元下方，在此期间，每个Cod配体在Rh(Cod)单元中交换其配位位置，(2)[Cp^*TaS_3Li_2(THF)_2]_2与(Ph_4P)_2(Fe_4S_4Cl4)，(Ph_4P)(Fe_3(Sph)_3)，或(Ph_4P)_2(Fe_2S_2Cl_2)在50ﾟC四氢呋喃中生成…更多的是Ta_&lt；&gt；2Fe簇合物，(Cp^*Tas_3)Fe^&lt；2-&gt；这一发现暗示了溶液中铁-硫团簇的解离。(3)在Cp^*TaCl4与Lis^Tbu的反应中，我们观察到氯离子逐步被硫酸盐取代。因此，在(1：3)Cp^Tacl_4/LiS^Tbu反应体系中，加入2当量的Lis^TbU的THF溶液得到Cp^*Tacl_2(S^Tbu)_2、Cp^*Tacl(S^Tbu)_2和Cp^*Tacl(S^Tbu)_3。当LiS^TBU的量增加到4当量时，发生了一个简单的C-S键断裂，生成了硫化物络合物Cp^*Tas(S^TbU)_2。在四氢呋喃中，Cp^*TaCl4与6-8当量的Lis^TbU反应的主要产物又是硫化物络合物。(4)我们用^&lt；&GT；H核磁共振分析了铀[Li_4(Dme)_4][U(SCH_2CH_2^S)_4]的流体行为，发现有两个动力学过程；一种是十二面体US8配位球中硫原子的位置交换，另一种是USCCS环的构象变化。测定了这些过程的活化参数。较少

(1)We have isolated variegated sulfide complexes from reactions of Li_2S_x(x=l, 2, 4)with Cp^*TaCl_4(Cp^*=eta^5-C_5Me_5). A common facet of these sulfide complexes is that they possess Li cations bound strongly to sulfur. By taking an advantage of having such lithiums, we found a new route to heteronuclear clusters comprising a common Cp^*TaS_3 unit. For example, [Cp^*TaS_3Li_2(thf)_2]_2 reacts with[RhCl(cod)]_2 to give the TaRh_2 trinuclear complex(Cp^*TaS_3)[Rh(cod)]_2. The structure was found not rigid in a solution, and the fluxional behavior was monitored by the ^1H-NMR signals arising from the olefinic protons in cod ligands. We postulate that the two Rh(cod)fragments migrate below the TaS^3 unit via a 3-coordinate intermediate, during which time each cod ligand switches its coordination site within the Rh(cod)unit,(2)The reaction of[Cp^*TaS_3Li_2(thf)_2]_2 with either(Ph_4P)_2(Fe_4S_4Cl_4), (Ph_4P)(Fe_3(SPh)_3), or(Ph_4P)_2(Fe_2S_2Cl_2)at 50ﾟC in THF gave rise to a formation of … More a Ta_<>2Fe cluster, (Cp^*TaS_3)Fe^<2->. This finding imply a possible dissociation of the iron-sulfur clusters in a solution.(3)In the reaction between Cp^*TaCl_4 and LiS^tBu we observed a stepwise replacement of chloride in with the thiolate. Thus, addition of a THF solution of 2 equiv LiS^tBu afforded Cp^*TaCl_2(S^tBu)_2 while Cp^*TaCl(S^tBu)_2 while Cp^*TaCl(S^tBu)_3 was prepared from the (1 : 3) Cp^*TaCl_4/LiS^tBu reaction system. When the amount of LiS^tBu was increased to 4 equiv, a facile C-S bond repture occurred to give rise to a sulfide complex, Cp^*TaS(S^tBu)_2. The main product of the reaction between Cp^*TaCl_4 and 6-8 equiv of LiS^tBu in THF is again the sulfide complex.(4)We have analyzed the fluydonal behavior of a homoleptic dithiolate complex of uranium[Li_4(dme)_4][U(SCH_2CH_2^S)_4] by ^<>H NMR to find that there are two dynamical processes ; one is a site exchange of sulfur atoms in the dodecahedral US8 coordination sphere, and the other is the conformation change of the USCCS ring. The activation parameters of these processes have been determined. Less