A Classical Example of a Disappearing Polymorph and the Shortest Intermolecular H⋅⋅⋅H Separation Ever Found in an Organic Crystal Structure

Missing in action: Neutron and X-ray diffraction studies at low temperatures reveal the delicate balances of attractive and repulsive intermolecular interactions in the dimorphs of 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose (the less stable polymorph is shown, O red, H blue, C gray). Very short intermolecular H⋅⋅⋅H contacts which are only present in the less stable crystal form are responsible for the disappearance of this polymorph.