| Abstrakt: |
Crystallization from methanol solution of mixtures of triphenylsilanol and 4,4'-bipyridyl has given a 1:1 adduct (I), Ph[sub 3]SiOH·C[sub 10]H[sub 8]N[sub 2], and three polymorphic 4:1 adducts (II)(IV), (Ph[sub 3]SiOH)[sub 4]·C[sub 10]H[sub 8]N[sub 2]. In (I), the components are linked by a single O-H···N hydrogen bond and by a number of CH···π(arene) hydrogen bonds to form a continuous threedimensional structure. Compounds (II)-(IV) are all triclinic, space group P&1macr;, with Z' values of 0.5, 1 and 4, respectively. The basic hydrogen-bonded aggregate is the same in each of (II)(IV), having a pair of silanol molecules linked to the bipyridyl via O-N···N hydrogen bonds and a further pair of silanol molecules linked to the first pair via O-H···O hydrogen bonds. In (II) there is just one such aggregate lying across a centre of inversion (Z' = 0.5) and in (III) there are two such aggregates, both lying across centres of inversion (Z' = 2 × 0.5 = 1). In (IV) there are six independent aggregates of this type, four of which lie across centres of inversion and two of which lie in general positions, so that Z' = (4 × 0.5) + 2 = 4. While the components in (I) are fully ordered, each of (II)-(IV) exhibits extensive disorder involving both the bipyridyl units and the phenyl rings of the silanol components. [ABSTRACT FROM AUTHOR] |
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