The hydrogen-bonding patterns in the pyranose and pyranoside crystal structures

Abstract

The hydrogen-bonding patterns in the crystal structures of the simple cyclic carbohydrates attempt to comply with three rules: (1) Maximize the hydrogen-bond energy by including all the hydroxyls and as many of the ring and glycosidic oxygens as possible. (2) Maximize the energy through the cooperative effect by forming infinite or long finite chains of hydrogen bonds. (3) Take into account the anomeric effect by including the anomeric hydroxyls as strong donors and poor acceptors of hydrogen bonds. These three rules are mutually incompatible. Compromises give rise to patterns of hydrogen bonding which can be divided into four distinct classes with related sub-groups. These patterns are distributed almost equally between the crystal structures of the 58 pyranoses, furanoses, pyranosides and furanosides included in this survey.