2-DIMENSIONAL LATTICE OF SUPERBOATS COMPOSED OF SILICON-CENTERED TETRAHEDRA

Four benzenecarboxylic acid groups attached to silicon, (4-CO2HC6H4)(4 )Si, form an infinite two-dimensional pleated sheet in the solid state composed of cyclic units of 78 heavy atoms In the shape of a large bo at-like structure held together by six complementary hydrogen-bonded u nits, Only three carboxylic acid groups per molecule are incorporated into the superboat. The material was crystallized from acetic acid. As a result, one molecule of acetic acid is bound to the fourth carboxyl ic acid group, preventing the structure from attaining a diamondoid la ttice, Sixfold repetition of interpenetrating lattices restricts poros ity. (C) 1997 by John Wiley & Sons, Ltd.