1,2,4,6-Thiatriazinyl Radicals and Dimers: Structural and Electronic Tuning through Heteroaromatic Substituent Modification

The
functionalization of thiatriazinyl (TTA) radicals with pyridyl
and thienyl moieties is described, and their influence at both the
molecular and solid-state level has been investigated. Comparative
electron paramagnetic resonance studies of 3,5-bis-(2-pyridyl)-1,2,4,6-thiatriazinyl
(Py2TTA) and 3,5-bis-(2-thienyl)-1,2,4,6-thiatriazinyl
(Th2TTA) reveal
the impact of heteroaromatic substitution on the electronic structure,
which is supported by density functional theory calculations. Single
crystal X-ray analysis emphasizes the importance of intermolecular
contacts on the crystal packing and demonstrates the potential for
structural control through S---N′ and N---HC′ interactions,
which are enhanced in Py2TTA and Th2TTA by the presence of the pyridyl and thienyl groups, respectively.
This work represents a fundamental study of heterocyclic aromatic
substitution in thiazyl-based radicals and investigates how varying
these functional groups influences the molecular properties and long-range
order within the supramolecular structure.