Crystal and molecular structures of 4,4′-bis(dimethylhydroxysilyl)-biphenyl and m-bis(dimethylhydroxysilyl)benzene

The crystal structures of 4,4′-bis-(dimethylhydroxysilyl)biphenyl (1) and m-bis(dimethylhydroxysilyl)benzene (2) are reported. Crystals of (1) are monoclinic, P21/n, with a 9.970(2), b 7.185(1), c 24.134(2) Å, β 98.795(8)°, and Z 4. Crystals of (2) are monoclinic, P21/n, with a 5.960(1), b 24.205(10), c 18.635(9) Å, β 97.14(1)°, and Z 8. In compound 1, a combination of OH⋯O hydrogen bonds and CH⋯π interactions results in the formation of sheets of enantiomeric pairs of helices, and these sheets are linked by additional CH⋯π interactions into a continuous three-dimensional network. In compound 2 both OH⋯O hydrogen bonds and CH⋯π interactions are also present but, in this case, hexagonal arrays of stacks of molecular dimers are formed.