SYNTHESIS, STRUCTURAL CHARACTERIZATION, AND REACTIVITY OF (ME3CCH2)2GAAS(SIME3)2GA(CH2CME3)2CL, ((ME3CCH2)2GAAS(SIME3)2)2, AND (ME3CCH2)2GA(CL).AS(SIME3)3

Reaction of 2 equiv of (Me3CCH2)2GaCl with (Me3Si)3As affords (Me3CCH2)2 activated GaAs(SiMe3)2Ga-(CH2CMe3)2Cl (1), the fourth example of a compound containing the Ga-As-Ga-X (X = Cl, Br) core, but the first wherein the organogallium four-membered ring with arsenic/halogen mixed bridging is not puckered. Compound 1, as well as (Me3CCH2)2GaCl, reacts with LiAs(SiMe3)2.2THF (1:1 mole ratio) to produce the common product [(Me3CCH2)2GaAs(SiMe3)2]2 (2), which on reaction with (Me3CCH2)2GaCl (1:2 mole ratio) gives 1 quantitatively. Mixing (Me3CCH2)2GaCl and (Me3Si)3As in a 1:1 mole ratio yields the adduct (Me3CCH2)2Ga(Cl).As(SiMe3)3 (3). Thermolysis of 3 did not afford 2, nor did its reaction with an additional 1 equiv of (Me3CCH2)2GaCl lead to 1 as the predominate product. Various physical and spectroscopic characterization data are presented for compounds 1-3, as well as the results of their X-ray crystal structure determinations. Crystal data: 1, monoclinic, space group P2(1)/c (C2h5), a = 12.412 (1) angstrom, b = 17.306 (1) angstrom, c = 20.238 (2) angstrom, beta = 119.34 (1)-degrees, V = 3790 (1) angstrom 3, Z = 4; 2, monoclinic, space group P2(1)/c (C2h4), a = 12.180 (1) angstrom, b = 12.744 (1) angstrom, c = 19.618 (2) angstrom, beta = 128.43 (1)-degrees, V = 2386 (1) angstrom 3, Z = 2; 3, monoclinic, space group P2(1)/c (C2h5), a = 12.486 (1) angstrom, b = 12.544 (1) angstrom, c = 19.985 (2) angstrom, beta = 101.73 (1)-degrees, V = 3065 (1) angstrom 3, Z = 4.