Stabilization of the tris(2-thienyl)methyl cation by formation of polymethine units. A thiophene S–S intramolecular interaction
Abstract
The tris(2-thienyl)methyl cation 2a+ is stabilized by delocalization over a conjugated polymethine framework; it shows restricted rotation about the C–S bond induced by S–S interaction and crystallizes as a statistically disordered racemic mixture of two enantiomeric species.