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Homoleptic hexa and penta gallylene coordinated complexes of molybdenum and rhodium
Timo Bollermann1, Thomas Cadenbach, Christian Gemel
1Anorganische Chemie II - Organometallics & Materials, Ruhr-Universität Bochum , D-44780 Bochum, Germany.
Abstract:
The reactions of molybdenum(0) and rhodium(I) olefin containing starting materials with the carbenoid group 13 metal ligator ligand GaR (R = Cp*, DDP; Cp* = pentamethylcyclopentadienyl, DDP = HC(CMeNC(6)H(3)-2,6-(i)Pr(2))(2)) were investigated and compared. Treatment of [Mo(η(4)-butadiene)(3)] with GaCp* under hydrogen atmosphere at 100 °C yields the homoleptic, hexa coordinated, and sterically crowded complex [Mo(GaCp*)(6)] (1) in good yields ≥50%. Compound 1 exhibits an unusual and high coordinated octahedral [MoGa(6)] core. Similarly, [Rh(GaCp*)(5)][CF(3)SO(3)] (2) and [Rh(GaCp*)(5)][BAr(F)] (3) (BAr(F) = B{C(6)H(3)(CF(3))(2)}(4)) are prepared by the reaction of GaCp* with the rhodium(I) compound [Rh(coe)(2)(CF(3)SO(3))](2) (coe = cyclooctene) and subsequent anion exchange in case of 3. Compound 2 features a trigonal bipyramidal [RhGa(5)] unit. In contrast, reaction of excess Ga(DDP) with [Rh(coe)(2)(CF(3)SO(3))](2) does not result in a high coordinated homoleptic complex but instead yields [(coe)(toluene)Rh{Ga(DDP)}(CF(3)SO(3))] (4). The common feature of 2 and 4 in the solid state structure is the presence of short CF(3)SO(2)O···Ga contacts involving the GaCp* or rather the Ga(DDP) ligand. Compounds 1, 2, and 4 have been fully characterized by single crystal X-ray diffraction, variable temperature (1)H and (13)C NMR spectroscopy, IR spectroscopy, mass spectrometry, as well as elemental analysis.
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