Crystal structure of 2,2,3,3-tetra­methyl-1,1,1,4,4,4-hexa­phenyl­tetra­germane

The mol­ecule of the title compound, C₄₀H₄₂Ge₄, lies with its central Ge-Ge bond on an inversion centre giving rise to a zigzag backbone of four tetra­hedrally coordinated Ge atoms. The symmetrically independent Ge-Ge bonds are slightly shorter than in other organo­tetra­germanes whereas the Ge-C_Ph (Ph = phen­yl) and Ge-C_Me (Me = meth­yl) distances have their usual values. In the crystal, (010) layers of Ph₆Me₄Ge₄ mol­ecules with a parallel orientation of the Ge₄ backbone exist, held together by van der Waals forces only. Main bond lengths in organo-substituted oligogermanes are compared.