Syntheses and Crystal Structures of Intramolecularly Stabilized Organo Aluminum, Gallium, and Indium Compounds Containing the C,P-Chelating o-Carboranylphosphino Ligand [o-C2

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• 作者：Jong-Dae Lee ; Jaejung Ko ; Minserk Cheong ; and Sang Ook Kang
• 刊名：Organometallics
• 出版年：2005
• 出版时间：November 21, 2005
• 年：2005
• 卷：24
• 期：24
• 页码：5845 - 5852
• 全文大小：207K
• 年卷期：v.24,no.24(November 21, 2005)
• ISSN：1520-6041

文摘

The new phosphino-o-carborane ligand HCab^P (1; Cab^P = closo-1-[(dimethylphosphino)methyl]-1,2-dicarbaborane) with substitution at the carbon and phosphorus atoms was usedfor the synthesis of the C,P-chelated bis(phosphino-o-carborane) group 13 metal complexes(Cab^C,P)₂MX (4). Reaction of LiCab^C,P (2; LiCab^C,P = closo-1-[(dimethylphosphino)methyl]-2-lithio-o-carborane) with MX₃ (M = Al, Ga, In; X = Cl, Br) in a 1:1 molar ratio producedthe tetracoordinated metallacyclic compound (Cab^C,P)MX₂ (3), in which the metal atom wasstabilized via intramolecular C,P-coordination. The corresponding bis-chelate complexes,(Cab^C,P)₂MX (4), were synthesized by reacting 3 with an additional C,P-chelate ligand 2.Complexes 4 were also formed upon reaction of 2 with MX₃ in a 2:1 molar ratio. The ¹H and¹³C NMR spectra of 4 revealed that intramolecular M-P coordination occurs in solution,resulting in the formation of pentacoordinated complexes (Cab^C,P)₂MX (4). The trigonalbipyramidal (tbp) coordination of the metal center was confirmed by single-crystal X-raydetermination of the complexes (Cab^C,P)₂GaCl (4b) and (Cab^C,P)₂InCl (4c). Similar intramolecularly base-stabilized gallanes, (Cab^C,P)GaMe₂ (5b) and (Cab^C,P)₂GaMe (6b), which weretetra- and pentacoordinated, respectively, were synthesized from the reaction of 3b and 4bwith LiMe or MeMgBr. The Lewis acid 3b added the base PMe₃ to yield the pentacoordinatedadduct (Cab^C,P)GaCl₂·PMe₃ (7b). The ¹H and ¹³C NMR spectra revealed that intramolecularGa-P coordination occurs in solution, resulting in a pentacoordinated structure.