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 ß-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.

Conformational polymorphism facilitates assignment of trans and cis-conformers of an alpha-substituted oligothiophene via IR spectroscopy.

Conformational polymorphism is exploited as a means to assign cis-trans and trans-trans conformations of an oligothiophene backbone using solid-state IR spectroscopy.