Ruthenium Complexes with the Stanna‐closo‐dodecaborate Ligand: Coexistence of η¹(Sn) and η³(BH) Coordination

Abstract

Four stanna-closo-dodecaborate complexes of ruthenium have been prepared and characterized by multinuclear NMR studies in solution and in the solid state. The solid-state structures of the dimeric zwitterions [[Ru(dppb)(SnB11H11)]2] (2) (dppb = bis(diphenylphosphino)butane), [[Ru(PPh3)2(SnB11H11)]2] (3), and the dianionic ruthenium complex [Bu3MeN]2[Ru(dppb)[2,7,8-(mu-H)3-exo-SnB11H11](SnB11H11)] (4) were determined by X-ray crystal structure analysis; they establish an unprecedented structural motif in the chemistry of heteroboranes and transition-metal fragments with the stanna-closo-dodecaborate moiety as a two-faced ligand that exhibits eta1(Sn) as well as eta3(B-H) coordination. The eta3-coordinated stannaborate in 4 and in the isostructural compound [Bu3MeN]2[Ru(PPh3)2[2,7,8-(mu-H)3-exo-SnB11H11](SnB11H11)] (5) shows fluxional behavior, which was studied in detail by using 31P[1H] EXSY and DNMR experiments. The activation parameters for the dynamic process of 5 are given.

Octahedral Coordination Compounds of the Ni, Pd, Pt Triad

“…[2] In its reaction with platinum electrophiles, we found complexes which are active catalysts in hydroformylation reactions; with the coinage metals, cluster formation is the dominant reaction; and with ruthenium complex fragments, ambident coordination modes together with dynamic behavior of the heteroborate were characterized. [3][4][5][6][7][8][9][10] To synthesize a diazabutadiene nickel complex with stanna-closo-dodecaborate as ligand, we treated the nickel halide [Ni(dpp-bian)Br 2 ] with three equivalents [SnB 11 H 11 ] 2À (Scheme 1). [11] The octahedral nickel complex 1 was isolated from this reaction mixture as purple crystals and was characterized by elemental analysis, mass spectrometry, X-ray crystal structure analysis (Figure 1), heteronuclear NMR spectroscopy (Figures 3 and 4) and 119 Sn Mössbauer spectroscopy ( Figure 6).The octaanionic complex [Ni(SnB 11 H 11 ) 6 ] 8À with nickel in the formal oxidation state IV is the product of an oxidation reaction, raising the question of the corresponding reduction product.…”

“…[3] Scheme 1. Synthesis of [Bu 3 NH] 8 [Ni(SnB 11 H 11 ) 6 ] (1). The homologous complexes of 1 with hexacoordinate palladium and platinum [M(SnB 11 H 11 ) 6 ] 8À (M = Pd (3), Pt (4)) were synthesized by substitution reactions starting with the respective hexachloride complexes and the sodium salt Na 2 [SnB 11 H 11 ] in a mixture of water and THF (Scheme 2).…”

Synthesis and Coordination Chemistry of a Chelating P–Sn Ligand Based on Stanna‐closo‐dodecaborate

“…[14a], , The other rhodium atom is coordinated by two B–H units of a borate. This type of coordination is well known in boron‐cluster coordination chemistry, and here, two B–H units act as a bidentate ligand . Both rhodium atoms are further coordinated in a cis arrangement by one carbonyl ligand and a phosphine moiety of the P–Sn ligand.…”

Germa‐closo‐dodecaborate: An Ambident and Flexible Coordinating Ligand

“…[9] Another interesting feature of the stannaborate cluster is its ability to coordinate through η 3 (B-H) towards transition-metal fragments. [10] [11,12] In this paper we report transition-metal complexes that contain the germanium nucleophile that coordinates tive 3 is high enough to react with [Mo(CO) 5 (thf)] to give the bimetallic complex [(triphos)Fe(GeB 11 H 11 )(MoCO) 5 ] (5), which contains an ambident coordinating germaborate moiety. The new compounds have been characterized by singlecrystal X-ray diffraction and elemental analysis.…”