1,2-Dihalodigermenes bearing bulky Eind groups: synthesis, characterization, and conversion to halogermylenoids.

1,2-Dihalodigermenes, (E)-(Eind)XGe[double bond, length as m-dash]GeX(Eind) (X = Br and Cl), bearing the fused-ring bulky Eind group (Eind = 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl) have been isolated as orange-yellow crystals by the ligand redistribution reaction between the diarylgermylene, (Eind)2Ge:, and GeX2·dioxane in toluene via the cleavage and recombination of the Ge-C and Ge-X bonds. The dihalodigermenes have a Ge[double bond, length as m-dash]Ge double bond character in the crystalline state, but dissociate into halogermylenes, (Eind)XGe:, in solution. The addition of excess LiBr to the THF solution of the bromogermylene, (Eind)BrGe:, led to the formation of an equilibrium mixture containing the lithium bromogermylenoid, [Li+][(Eind)GeBr2]-. The bromogermylenoid can be isolated as a cryptand-separated potassium ion pair, [K+(crypt-222)][(Eind)GeBr2]-, which has been structurally characterized.