Design and understanding of solid-state and crystalline materials
Paper
CrystEngComm, 2004, 6, 535 - 540, DOI: 10.1039/b412962h
The crystal structure of an unstable polymorph of
-D-alloseP. Arnaud Bonnet, Jacco van de Streek, Andrew V. Trask, W. D. Samuel Motherwell and William Jones
The crystal structure of a new polymorph, Form II, of
-D-allose has been determined by X-ray powder diffraction. The unit cell is hexagonal, a=b= 16.598 Å, c= 4.856 Å, 
=
= 90°, 
= 120°, space group P62 with Z= 6, Z
= 1. The molecule adopts the 4C1 chair-conformation, with a torsional change of conformation of the O6 side-chain compared to the orthorhombic Form I. The two polymorphs share a common feature of a stacked hydrogen bonded column of molecules in the short axis direction. The structures differ in hydrogen linking of these columns. The more stable Form I has more immediate neighbours linked by hydrogen bonds to a reference molecule, and higher crystal density than Form II.
RSS feed