Crystal and molecular structure of syndiotactic 2,4,6-triphenylheptane, a polystyrene model moleculE
Résumé
The crystal and molecular structures of syndiotactic 2,4,6-triphenylheptane have been determined by direct methods and refined from X-ray diffraction data recorded with a four-circle diffractometer and Mo Kα radiation. The unit cell is monoclinic, space group P21/c; at room temperature, a = 16.831, b = 9.104, c = 34.390 Å and β = 128.11°. It is found that the two molecules in the asymmetric unit have the same trans conformation of the chain, with aromatic rings virtually perpendicular to the chain.