Guest-Host Systems of 1,3,5-Tristyrylbenzenes

(E,E,E)-1,3,5-Tris(3,4,5-trimethoxystyryl)benzene (1a) forms monoclinic crystals of the space group P21/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 C3 arrangement. (E,E,E)-1,3,5-Tris- (3,4,5-tripropoxystyryl)benzene (1b) forms monoclinic crystals of the space group P21/c. The C3 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 ar…