Cobalt, Rhodium, Iridium, and Ruthenium Carbonyl Complexes with Stanna-closo-dodecaborate: 103Rh NMR, 119Sn Mössbauer Spectroscopy, and Solid-State 119Sn NMR

Depending on the stoichiometry stanna-closo-dodecaborate [SnB11H11]2– reacts with the dimeric carbonyl complex [Rh(CO)2Cl]2 to give a dinuclear rhodium coordination compound with bridging tin ligands, [Et3MeN]6[Rh2(CO)4(SnB11H11)4] (1), or a pentagonal-bipyramidal complex, [Et4N]5[Rh(CO)2(SnB11H11)3] (2), with the carbonyl ligands in axial position. The analogous iridium and cobalt complexes [Et4N]5[Ir(CO)2(SnB11H11)3] (3) and [Me4N]5[Co(CO)2(SnB11H11)3] (4) exhibit a pentacoordinated structure with the tin ligands in axial positions. The dimeric ruthenium chlorocarbonyl complex [Ru(CO)3Cl2]2 reacts with four equivalents of the tin nucleophile to give the octahedrally coordinated ruthenium complex [Et3MeN]4[Ru-cis-(CO)2-cis-Cl2-trans-(SnB11H11)2] (5). The synthesized coordination compounds were characterized by X-ray crystal structure analysis, by 103Rh, 119Sn, and 11B NMR spectroscopy in solution, and in the case of the rhodium complexes 1 and 2 by 119Sn solid-state NMR and 119Sn Mössbauer spectroscopy.

根据化学计量比，锡杂闭式十二硼烷二阴离子[SnB₁₁H₁₁]²⁻可与二聚羰基配合物[Rh(CO)₂Cl]₂发生反应，分别得到带有桥联锡配体的双核铑配位化合物[Et₃MeN]₆[Rh₂(CO)₄(SnB₁₁H₁₁)₄]（化合物1），以及轴向位点带有羰基配体的五角双锥配合物[Et₄N]₅[Rh(CO)₂(SnB₁₁H₁₁)₃]（化合物2）。类似的铱与钴配合物[Et₄N]₅[Ir(CO)₂(SnB₁₁H₁₁)₃]（化合物3）与[Me₄N]₅[Co(CO)₂(SnB₁₁H₁₁)₃]（化合物4）均呈现五配位结构，其锡配体位于轴向配位位点。二聚氯羰基钌配合物[Ru(CO)₃Cl₂]₂与四倍当量的锡亲核试剂反应，得到八面体配位的钌配合物[Et₃MeN]₄[Ru-顺式-(CO)₂-顺式-Cl₂-反式-(SnB₁₁H₁₁)₂]（化合物5）。所合成的各类配位化合物均通过X射线晶体结构分析、溶液相¹⁰³Rh、¹¹⁹Sn及¹¹B核磁共振波谱进行表征；其中针对铑配合物1和2，还额外采用了¹¹⁹Sn固态核磁共振波谱与¹¹⁹Sn穆斯堡尔谱完成表征。