Crystal and molecular structures of syndiotactic 2,4,6-8-tetraphenylnonane, a polystyrene model molecule

The crystal and molecular structures of syndiotactic 2,4,6,8-tetraphenylnonane have been determined by direct methods and refinement from X-ray diffraction data. The unit cell is quadratic (space group I4 1/g̊) with, at room temperature, g̊  13.740, c  27.20 Å, V = 5135.7 Å, Z = 8 and contains one molecule in the asymmetric unit; the final weighted residual factor is r = 0.065 for 1541 observed reflexions. It is found that the aliphatic chain exhibits a gauche-gauche conformation in the middle of the chain.