Synthesis and Characterization of Novel Organogallium-Phosphorus Compounds: X-Ray Crystal Structures of Ph2GaP(SiMe3)2Ga(Ph)2Cl, Ph2(Cl)Ga. P(SiMe3)3, and Ph3Ga.P(SiMe3)3

A Ga-P-Ga-Cl ring containing compound, Ph2GaP(SiMe3)2Ga(Ph)2C1 (1), is reported. Compound 1 is an example of a four-membered ring system with mixed bridging of the two gallium centers and was prepared via the reaction of Ph2GaCl with P(SiMe3)3 in a 2:1 mole ratio in either toluene or pentane. Curiously, 1 was originally isolated as a minor product (ca 5% yield) from the reaction of LiP(SiMe3)2 with Ph2GaCl in a 1: 1 mole ratio. X-ray crystallographic analyses shows the Ga-P-Ga-Cl ring of 1 to be non-planar. The reaction of Ph2GaCl and P(SiMe3)3 in a 1:1 mole ratio in either toluene or pentane yields Ph2(Cl)Ga. P(SiMe3)3 (2). Compound 3, Ph3Ga.P(SiMe3)3, was also originally isolated as a minor product (ca. 10%) from the reaction of LiP(SiMe3)2 with Ph2GaCl in a 1:1 mole ratio and is an additional reported example of an adduct formed through ligand redistribution involving LiE(SiMe3)2 (E = P or As) as a reactant. The straightforward synthesis of 3 can be accomplished by the 1:1 mole reaction of Ph3Ga and P(SiMe3)3 in pentane. Both 2 and 3 are structural examples of adducts containing a Ga-P bond with aryl ligands on the gallium center. Compound 1 belongs to the monoclinic system, space group P21/c, with z = 4, a = 10.579(2) Angstrom, b = 15.653(5) Angstrom, c = 20.428(4) Angstrom, and = 91.80(2)deg. Compound 2 crystallizes in an orthorhombic system, space group P212,21, with z 4, a = 9.3320(10) Angstrom, b = 9.768(2) Angstrom, and c = 30.581(6) Angstrom. Compound 3 belongs to the monoclinic system, space group P2,/n, with z = 4, a = 18.81(3) Angstrom, b = 19.25(2) Angstrom, c = 18.93(2) Angstrom, and beta = 112. 8(1)deg.