Control of Solid-State Photodimerization of trans-Cinnamic Acid by Double Salt Formation with Diamines

Article abstract of DOI:10.1016/0040-4039(95)01209-Z

By double salt formation, diamines can steer the solid-state <2+2> photodimerization of trans-cinnamic acid (1).Thus, the yields for the photodimerization were significant only in three double salts, i.e., the ones with tn and t- and c-chxn, which are assumed to have an overlap structure.The resultant photodimer is generally β-truxinic acid, although in one case, ε-truxillic acid was formed. α-Truxillic acid was not produced from any of the double salts studied.The X-ray crystal structures of three double salts of low photoreactivity (1*en, 1*pen, 1*hen) were consistent with Schmidt's rule.