Synthesis and Reactivity of Organotin Compounds Containing the C,P-Chelating o-Carboranylphosphino Ligand [o-C2B10H10PPh2-C,P](CabC,P). X-ray Structures of (CabC,CH2P)SnMe2Br, [(CabC,P)SnMe2]2Pd, and [(CabC,P)SnMe2]Pd(PEt3)Cl

The triorganotin halides (Cab C,P )SnMe 2 X ( 2a, X = Cl; 2b, X = Br) and a tetraorganotin compound (Cab C,P )SnMe 3 ( 7 ), containing the o -carboranylphosphino ligand (Cab C,P ), have been prepared by the reaction of LiCab C,P ( 1 ) with Me 2 SnX 2 and Me 3 SnCl, respectively. 1 H, 13 C, 31 P, and 119 Sn NMR spectroscopy indicate that the tin centers in 2a and 2b are pentacoordinate as a result of intramolecular Sn−P coordination, whereas the tin center in 7 is tetracoordinate. The substitution reactions of 2a using NaI, NaN 3, NaCpFe(CO) 2, and NaB(CN)H 3 afforded the substituted products (Cab C,P )SnMe 2 X ( 3, X = I; 4, X = N 3; 5, X = CpFe(CO) 2; 6, X = H). The Wurtz-type coupling reaction of 2a with sodium afforded the distannane. The reaction of the distannane 10 with Pd 2 (dba) 3 ·CHCl 3 afforded the bis(stannyl)palladium complex 11 . When compounds 2a and 2b were employed in the reaction with Pd 2 (dba) 3, the halo-bridged metal complexes 12a and 12b were isolated. The crystal structures of 9b, 11, and 13 were determined by X-ray structural studies. As a result of the Sn−P interaction, the tin atom in 9b exhibits a distorted trigonal-bipyramidal configuration.