Supramolecular silanol chemistry:: Inclusion complexes of 1,3,5-tris(diisopropylhydroxysilyl)benzene and 4,4′-bis(pyridines)

The trisilanol 1,3,5-(HOiPr(2)Si)(3)C6H3 (5), a novel building block for applications in supramolecular chemistry, has been prepared via the intermediates 1,3,5-(H'Pr2Si)3C6H3 (6) and (CliPr2Si)(3)C6H3 (7). The inclusion complexes 5(.)0.5H(2)O, 5(.)bpy(-)0.5H(2)O, 5(.)bpe, 5(.)azpy and 5(.)bpa have been investigated by X-ray crystallography [bpy = 4,4 '-bipyridine, bpe = (E)-bis(4-pyridyl)ethylene, azpy = 4,4 '-azopyridine, bpa = bis(4-pyridyl)aceylene]. The ratio between donor and acceptor molecules is always 1:1 and the crude supramolecular motifs are very similar for 5(.)bpy(.)0.5H(2)O, 5(.)bpe, 5(.)azpy and 5(.)bpa. The trisilanol molecules form 1D chains, which are connected by nearly perpendicular 4,4'-bis(pyridine) molecules to give rise to formation of 2D grid networks featuring O-H center dot center dot center dot O(H)Si and O-H center dot center dot center dot N hydrogen bonds. Differences are observed in the shape and size of the voids defined by the 2D grids. The smaller voids are blocked by trisilanol molecules of adjacent 2D networks in case of 5-bpy(.)0.5H(2)O and 5(.)bpe. In case of 5(.)azpy, the larger voids are filled by interpenetration of the same 2D networks. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)