SOLID-STATE BEHAVIOR OF VINYL QUINONES

2,5-Bisvinyl-1,4-benzoquinones 1 and 2-vinyl-1,4-benzoquinones 2 subst ituted with aryl or ester end groups have been synthesized. The 2,5-bi sstyryl-1,4-benzoquinones 1 (R=phenyl, p-tolyl, o-tolyl) crystallize w ith a 7 Angstrom-stacking axis. But only for the o-tolyl derivative th e contacts between the vinyl groups are close enough to allow a four-c enter type photopolymerization. The ester derivative 1 (R=COOEt) has a layer structure and can be photooligomerized in the crystal. The gene rated cyclobutane subgroups have twofold symmetry. The vinylquinones 2 (R=aryl) may be dimerized photochemically in the crystal at the vinyl groups to centrosymmetric cyclobutanes. Crystals with 4 Angstrom stac king axis are also photoreactive.