1378266-34-2Relevant articles and documents
Hydrogen-bonded helical self-assembly of sterically-hindered benzyl alcohols: Rare isostructurality and synthon equivalence between alcohols and acids
Moorthy, Jarugu Narasimha,Mandal, Susovan,Venugopalan, Paloth
, p. 2942 - 2947 (2012)
Hydrogen-bonded aggregation has been examined in a series of sterically hindered benzyl alcohols with an objective to explore how sterics influence the otherwise inconsistent and variable synthons generally observed for alcohols. All the sterically hindered alcohols 8-15 were found to adopt a helical hydrogen-bonded synthon, and crystallize uniformly in the rare I41/a space group, for which the statistical prevalence in the CSD is abysmally small. Remarkably, the crystal packing in all of these alcohols is found to be isostructural to analogous sterically hindered carboxylic acids 1-4. The reason as to why all alcohols sustain the helical motif, despite being aggregated via rather weak hydrogen bonds as compared those in analogous acids 1-4 is traceable to unique molecular topology that permits close-packing as well as exploitation of intermolecular interactions comprehensively. It is shown that sterics permit a very rare packing as well as synthon equivalence between carboxylic acids and alcohols. It emerges from the present study that the hydrogen-bonded synthons of strongly interacting functional groups are not necessarily reproducible when sterics are brought into picture. By the same token, the synthons may sustain even when the interactions are weak when close packing is ensured.
