Structural studies of polyethers, [‐(CH₂)m‐O‐]n. III¹. Molecular and crystal structure of polytetrahydrofuran

The molecular and crystal structure of polytetrahydrofuran has been determined by X‐ray diffraction analysis. The unit cell dimensions are a = 5.48, b = 8.73, c (fiber axis) = 12.07 Å., and β = 134.2°. The space group is C 2/ c — C . Two molecular chains pass through the unit cell. The skeleton of the molecular chain has a planar zig‐zag conformation and the zig‐zag plane is parallel to the (100)‐plane. The infrared dichroism and pleochroism were measured, and the tentative assignments for the infrared absorption bands were given and discussed.