The crystal and molecular structure of tri-o-ethylamylose (tea 3)

The crystal and molecular structure of a tri-O-ethylamylose polymorph, TEA 3, has been solved by stereochemical conformation and packing analysis, combined with X-ray fibre diffraction analysis. The unit cell is orthorhombic, space group P2₁2₁2₁, with a  15.36 (±0.03) Å, b  12.18 (±0.05) Å, and c (fibre repeat)  15.48 (±0.01) Å. The actual chain conformation is a 4₃ helix with the EtO-6 group in the tg position, as was found in the polymorph TEA 1.