Cobalt, Rhodium, Iridium, and Ruthenium Carbonyl Complexes with Stanna-<i>closo</i>-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.