Three polymorphs (α, β, and δ) of d‐mannitol at 100 K |
| |
Authors: | Haidy Nasr Kamel Frank R Fronczek Marc Slattery |
| |
Abstract: | In the monoclinic δ polymorph of d ‐mannitol, C6H14O6, both the molecule and the packing have approximate twofold rotational symmetry. The P21 structure thus approximates space group C2221, and the α′ polymorph, previously reported in that space group, is almost certainly identical to the δ polymorph. However, torsion angles along the main backbone of the molecule deviate from twofold symmetry by as much as 7.4 (3)° and the hydrogen‐bonding pattern does not conform to the higher symmetry. The α polymorph reported here is identical to the previously reported κ polymorph, and the low‐temperature structure of the β polymorph agrees well with previously reported room‐temperature determinations. The range of C—O bond lengths over the three polymorphs is 1.428 (2)–1.437 (4) Å, and the range of C—C distances is 1.515 (4)–1.5406 (19) Å. The δ polymorph has the highest density of the three, both at room temperature and at 100 K. |
| |
Keywords: | |
|
|