Resorcinol-templated head-to-head photodimerization of a thiophene in the solid state and unusual edge-to-face stacking in a discrete hydrogen-bonded assembly

A head-to-head photodimerization of a β-substituted thiophene stacked face-to-face in the solid state using a ditopic hydrogen-bond-donor template is reported. The face-to-face stacking is attributed to contributions of intertemplate forces, which contrasts an assembly wherein the same thiophenes stack edge-to-face yet maintain a discrete hydrogen-bonded structure.