Topochemistry. Part 38. Photodimerisation in mixed crystals of trans-cinnamamides and of trans-stilbenes

Abstract

The phase relations in systems of two cinnamamides and of two trans-stilbenes are described. The solid-state photodimerisation of the stilbene system has been investigated, while that of the cinnamarides has previously been reported. The results are consistent with a model in which the reaction takes place in the bulk of crystals composed of random substitutional solid solutions. The model can be refined by considering a slight tendency for like molecules to aggregate in these solutions. There is no evidence for a special role of eutectics. In systems in which a third solid phase of intermediate composition is present the reactivity results can be interpreted by alternative model.