Neutral complexes of gallium(II) containing gallium-gallium bonds

Abstract

The complexes formed between the "gallium dihalides" (Ga2X4) and 1,4-dioxane (diox), Ga2X4-2(diox) (X = Cl, Br, I), have been reinvestigated. Ga2Cl4'2C4H802 forms triclinic crystals, space group Rl, with a -8.829 (5) Á, b = 9.101 (5)A, c = 10.82 (1) A, a = 107.27°, ß = 91.73 (2)°, y = 72.34 (2)°, Z = 2, Dcalcd = 1,943 g cm*3, and £>measd = 1.95 g cm"3.The structure has been solved from 3034 diffractometer-measured intensities with Mo Ka radiation ( 0.7107 A) and refined by full-matrix least squares to R = 0.085. The crystal structure shows that the complex is a discrete molecule containing a gallium-gallium bond of length 2.406 (1) A with dioxane acting as a monodentate ligand. Spectroscopic and other evidence is presented which shows that the bromide and iodide complexes have a similar structure.

Neutral complexes of the indium dihalides

“…To fully explain these facts it is necessary to consider the mixing of the various modes and this is not possible with the available data. Mixing effects in analogous gallium systems have been previously discussed (1,14).…”

“…Recent crystal structure determinations have confirmed the presence of these bonds in Ga2X4.2disxan (X = C1, Br) (1,3) and Ga2Br4. 2pyridine (4).…”

“…Although the gallium halides Ga,X4 are ionic mixed oxidation state compounds they react with many ligands to form neutral gallium-gallium bonded complexes (1,2). Recent crystal structure determinations have confirmed the presence of these bonds in Ga2X4.2disxan (X = C1, Br) (1,3) and Ga2Br4.…”

“…conductivity measurements show that Ga2C14. 2dioxan is ionic in nitrobenzene solution whereas the solid state structure is covalent (1,11).…”

The structure of catena-tribromo-μ-(1,4-dioxane-O,O')-thallium(III), [TlBr3(C4H8O2)]

“…As part of a study into the stereochemistry of thallium we report the crystal structure of TIBr3.dioxane in this paper. Dioxane is able to act as a monodentate ligand (Beamish, Small & Worrall, 1979) or bridging bidentate ligand towards Group III Lewis acids (Boardman, Small & Worrall, 1983) so that a number of geometries are possible.…”