Shanghai Key Laboratory of Molecular Catalysis and Innovative Material, Department of Chemistry, Fudan University, Shanghai 200433, P.R. China.
Chemistry. 2010 Oct 18;16(39):12017-27. doi: 10.1002/chem.201001278.
Monophosphine-o-carborane has four competitive coordination modes when it coordinates to metal centers. To explore the structural transitions driven by these competitive coordination modes, a series of monophosphine-o-carborane Ir,Rh complexes were synthesized and characterized. [CpM(Cl)(2){1-(PPh(2))-1,2-C(2)B(10)H(11)}] (M=Ir (1a), Rh (1b); Cp=η(5)-C(5)Me(5)), [CpIr(H){7-(PPh(2))-7,8-C(2)B(9)H(11)}] (2a), and [1-(PPh(2))-3-(η(5)-Cp)-3,1,2-MC(2)B(9)H(10)] (M=Ir (3a), Rh (3b)) can be all prepared directly by the reaction of 1-(PPh(2))-1,2-C(2)B(10)H(11) with dimeric complexes [(CpMCl(2))(2)] (M=Ir, Rh) under different conditions. Compound 3b was treated with AgOTf (OTf=CF(3)SO(3) (-)) to afford the tetranuclear metallacarborane [Ag(2)(thf)(2)(OTf)(2){1-(PPh(2))-3-(η(5)-Cp)-3,1,2-RhC(2)B(9)H(10)}(2)] (4b). The arylphosphine group in 3a and 3b was functionalized by elemental sulfur (1 equiv) in the presence of Et(3)N to afford [1-{(S)PPh(2)}-3-(η(5)-Cp*)-3,1,2-MC(2)B(9)H(10)] (M=Ir (5a), Rh (5b)). Additionally, the 1-(PPh(2))-1,2-C(2)B(10)H(11) ligand was functionalized by elemental sulfur (2 equiv) and then treated with [(CpIrCl(2))(2)], thus resulting in two 16-electron complexes [CpIr(7-{(S)PPh(2)}-8-S-7,8-C(2)B(9)H(9))] (6a) and [CpIr(7-{(S)PPh(2)}-8-S-9-OCH(3)-7,8-C(2)B(9)H(9))] (7a). Compound 6a further reacted with nBuPPh(2), thereby leading to 18-electron complex [CpIr(nBuPPh(2))(7-{(S)PPh(2)}-8-S-7,8-C(2)B(9)H(10))] (8a). The influences of other factors on structural transitions or the formation of targeted compounds, including reaction temperature and solvent, were also explored.
当单膦-o-卡硼烷与金属中心配位时，它有四种竞争配位模式。为了探索这些竞争配位模式驱动的结构转变，我们合成并表征了一系列单膦-o-卡硼烷 Ir,Rh 配合物。[CpM(Cl)(2){1-(PPh(2))-1,2-C(2)B(10)H(11)}]（M=Ir(1a), Rh(1b)；Cp=η(5)-C(5)Me(5)），[CpIr(H){7-(PPh(2))-7,8-C(2)B(11)H(11)}]（2a）和[1-(PPh(2))-3-(η(5)-Cp)-3,1,2-MC(2)B(10)H(10)]（M=Ir(3a), Rh(3b)）均可直接通过 1-(PPh(2))-1,2-C(2)B(10)H(11)与二聚体配合物[(CpMCl(2))(2)]（M=Ir，Rh）在不同条件下反应得到。将化合物 3b 用 AgOTf（OTf=CF(3)SO(3)(-)）处理，得到四核金属卡硼烷[Ag(2)(thf)(2)(OTf)(2){1-(PPh(2))-3-(η(5)-Cp)-3,1,2-RhC(2)B(10)H(10)}(2)]（4b）。3a 和 3b 中的芳基膦基团在存在 Et(3)N 的情况下与元素硫（1 当量）反应，得到[1-{(S)PPh(2)}-3-(η(5)-Cp*)-3,1,2-MC(2)B(10)H(10)]（M=Ir(5a), Rh(5b)）。此外，1-(PPh(2))-1,2-C(2)B(10)H(11)配体用元素硫（2 当量）进行官能化，然后与[(CpIrCl(2))(2)]反应，得到两个 16 电子配合物[CpIr(7-{(S)PPh(2)}-8-S-7,8-C(2)B(9)H(9))]（6a）和[CpIr(7-{(S)PPh(2)}-8-S-9-OCH(3)-7,8-C(2)B(9)H(9))]（7a）。化合物 6a 进一步与 nBuPPh(2)反应，得到 18 电子配合物[CpIr(nBuPPh(2))(7-{(S)PPh(2)}-8-S-7,8-C(2)B(10)H(10))]（8a）。我们还研究了其他因素对结构转变或目标化合物形成的影响，包括反应温度和溶剂。
