Hydrogen-bonded ladders formed by crystalline diols

作者：Bishop R^*; Craig DC; Nguyen VT; Scudder ML

来源：Australian Journal of Chemistry, 2001, 54(9-10): 637-641.

DOI：10.1071/CH01107

Certain diol molecules crystallize from solution as unidirectional double-stranded ladders. When these two strands assemble in-phase, a step-ladder arrangement results with the diols linked by (O-H)(4) cycles of hydrogen bonds. Using racemic diol samples, the preferred arrangement has two enantiomerically pure strands of opposite handedness. If the two strands assemble out-of-phase, a staircase-ladder results where the molecules are connected by a hydrogen-bonded (O-H)(n) chain. The preferred arrangement contains enantiomerically pure diol molecules surrounding a 2(1) screw axis. If a racemic diol is used then either the crystals contain both (+)- and (-)- ladders or, alternatively, self-resolution occurs to yield a conglomerate. New diols (7)-( 9) were synthesized and an X-ray investigation confirmed the prediction that these would produce further double-stranded ladders. These structures revealed new variants of the staircase-ladder where both enantiomers are present, inclusion compounds are formed, or crystallographically independent diol molecules are involved.

• 出版日期2001