Flip-flop hydrogen bonding in a partially disordered system

  title={Flip-flop hydrogen bonding in a partially disordered system},
  author={Wolfram Saenger and Ch. Betzel and Brian E. Hingerty and Geoffrey M. Brown},
Cyclodextrins have proved useful as model systems for the study of hydrogen bonding1, α-Cyclodextrin (α-CD) crystal-lizes from water as a hexahydrate having well defined hydrogen bonds (O—H…O) in linear and circular arrangements favouring ‘endless’ …O—H…O—H…O—H… chains1–3. The larger β-cyclodextrin (β-CD) forms a crystalline dodecahydrate, β-CD·12H2O in which X-ray localization of the hydroxyl hydrogen atoms is made difficult because 25 of the 45 hydroxyl groups are statistically disordered and… CONTINUE READING