The crystal structure of the syndiotactic polystyrene-toluene molecular compound was studied by X-ray diffraction. The crystal data are as follows: monoclinic system, space group P21/a (no. 14), a=17.58, b= 13.26, c(chain axis)=7.71 A, 7= 121.2 °, eight monomer units (two chains) and two toluene molecules per unit cell, the molar ratio of monomer: toluene being 4:1. The polymer chains take a twofold helical structure of (-TTGG-)2 conformation, and the packing of the polymer chains enables each toluene molecule to occupy an isolated hole between the benzene rings of adjacent polymer chains. The molecular compounds with benzene, chlorobenzene, p-xylene, 1,2,4-trichlorobenzene and so on are isomorphous to the toluene molecular compound. These molecular compounds are commonly transformed on heating between 120 and 150°C to another crystalline phase free from the guests, in which the polymer chains retain the helical structure.
Посилання на статтю:
Structural study on syndiotactic polystyrene: 2. Crystal structure of molecular compound with toluene / Yozo Chatani*, Yukio Shimane and Tomoko Inagaki and Toshikazu Ijitsu, Toshimitsu Yukinari and Haruo Shikuma // Polymer. – 1993. – Vol 34. – P. 1620-1624.