C. De Rosa et al., Crystal structure of the clathrate delta form of syndiotactic polystyrene containing 1,2-dichloroethane, POLYMER, 40(8), 1999, pp. 2103-2110
The crystal structure of the clathrate delta form of syndiotactic polystyre
ne containing 1,2-dichloroethane is presented. Polymer chains in s(2/1)2 he
lical conformation and 1,2-dichloroethane molecules are packed in the monoc
linic unit cell with axes a = 17.11 Angstrom, b = 12.17 Angstrom, c = 7.70
Angstrom and gamma = 120 degrees according to the space group P2(1)/a. The
crystalline density of the clathrate delta form is 1.23 g cm(-3) with two c
hains (eight monomer units) and two I,2-dichloroethane molecules inside the
unit cell. Molecules of 1,2-dichloroethane occupy isolated cavities betwee
n the benzene rings of adjacent polymer chains and are essentially only in
the trans conformation. The location and the conformation of the 1,2-dichlo
roethane molecule are such that both chlorine atoms are sandwiched between
two benzene rings of the same polymer chain. (C) 1999 Elsevier Science Ltd.
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