Abstract: | The four-center photopolymerization of five diolefinic compounds has been investigated by x-ray crystal analysis. A common packing feature is found for the photopolymerizable crystals and all polymers are three-dimensionally oriented. Topotaxies observed are classified according to the coincidence of space group and the three crystal axes, between monomer and polymer. The polymerization mechanism is discussed on the basis of the topotaxies and it is concluded that the polymerization is lattice controlled over the whole reaction process. |