Guest-host systems of 1,3,5-tristyrylbenzenes

摘要

(E,E,E)-1,3,5-Tris(3,4,5-trimethoxystyryl)benzene (1a) forms monoclinic crystals of the space group P2(1)/c. Incorporation of three transoid diacetyl guest molecules between the three arms leads to triclinic crystals of the space group P1. The styryl groups, originally present in a nonsymmetrical conformation, are simultaneously transformed to a C-3 arrangement. (EEE)-1,3,5-Tris(3,4,5-tripropoxystyryl)benzene (1b) forms monoclinic crystals of the space group P2(1)/c. The C-3 arrangement of the styryl groups is present in the first, the unsymmetrical arrangement in the second modification. Incorporation of two acetone guests in the largest and the middle-sized angle space between the styryl arms in the unsymmetrical arrangement, leads to monoclinic crystals of the space group P2(1). The third (smallest) angle space is filled with a propoxy chain of the neighboring molecule. The pure host crystals show significant deviations from planarity which are strongly reduced by the incorporation of the guest molecules. [References: 12]