Synthesis and Complete Characterization of a Gallium-Mixed-Pnicogen Four-Membered-Ring Compound: I 2 GaAs(SiMe 3 ) 2 Ga(I) 2 P(SiMe 3 ) 2

Abstract

The first four-membered ring compound containing two gallium atoms bridged by two different Group 15 elements. I₂GaAs(SiMe₃)₂Ga(I) ₂P(SiMe₃)₂ (l), to be completely characterized was synthesized by both the equilibration of [I₂G_aAs(SiMe₃)₂]₂ (2) and [I₂GaP(SiMe₃)₂]₂ (3) in a 1 : 1 mole ratio and the direct reaction of GaI₃ with As (SiMe₃)₃ and P(SiMe₃)₃ in a 2 : 1 : 1 mole ratio. Single-crystal X-ray structures were determined for both 1 and 3. Crystals of 1 belong to the orthorhombic system, space group Pbca, with a = 17.349 (3), b = 13.9187(21),c = 13.7570(24)Å, V = 3322.0(10) ų, D_calc = 1.879 g cm⁻³, for Z = 4; the average Ga-As/P bond length is 2.44 Å, and crystals of 1 are isomorphous with those of 2. Crystals of 3 belong to the monoclinic system, space group P2₁/c, with a = 11.040(9), b = 10.228(4), c = 19.619(9) Å V = 2169.4(22) ų, D_calc= 1.816 g cm⁻³ for Z = 4; the average Ga-p bond length is 2.39 Å.