2,2,6,6-Tetrakis(biphenyl-2-yl)-4,4,8,8-tetramethylcyclotetrasiloxane

Abstract

The title compound, [–Si(C12H9)2OSi(CH3)2O–]2, was obtained unintentionally as the product of an attempted crystallization of caesium bis(biphenyl-2,20-diyl)fluorosilicate from dimethylformamide. In the crystal, the molecule is located on an inversion center and the siloxane ring adopts a twist-chair conformation with the two dimethyl-substituted Si atoms lying 0.7081 (5) A ° out of the plane defined by the two bis(biphenyl-2-yl)-substituted Si atoms and the four O atoms. In each Si(C12H9)2 unit, the orientation of one terminal phenyl ring relative to the phenylene ring of the other biphenyl moiety suggests a parallel displaced – stacking interaction [centroid distance = 4.2377 (11) A ° and dihedral angle = 15.40 (9) ]