Ga2I2[C(SiMe3)3]2– an organogallium(II) halide containing a Ga–Ga single bond

Treatment of the tetrahedral, tetranuclear gallium(I) cluster compound Ga4[C(SiMe3)3]4(5) with a mixture of AlI3 and ICl afforded in 58% yield the yellowish dinuclear digallium(II) compound Ga2I2[C(SiMe3)3]2(6), an X-ray crystallographic study of which has shown it to contain a nonplanar (symmetry C2) Ga2I2C2 skeleton and two three-coordinate gallium(II) atoms linked by a single gallium–gallium bond. DFT calculations on 6 and related compounds with alternative structures and the molecular structure of the organogallium(III) iodide, Ga2I4[C (SiMe3)3]2(7) are also described and discussed.