Direct Structural Understanding of a Topochemical Solid State Photopolymerization Reaction

Hitherto, direct structural characterization of polycrystalline product phases obtained in solid state polymerization reactions has been limited by the lack of appropriate experimental techniques for structure determination. This paper demonstrates the opportunity to apply modern powder X-ray diffraction techniques for carrying out complete structure determination in such cases, by reporting the structural properties of the polymer phase obtained in the solid state photopolymerization reaction of 2,5-distyrylpyrazine. The structure of the polymer phase, for which structure solution was carried out using the direct-space genetic algorithm technique followed by Rietveld refinement, demonstrates directly the topochemical nature of this solid state reaction.