Quinonoid mesoionic compounds having a 2, 3-diphenyltetrazolium ring were synthesized and characterized spectroscopically. Compounds possessing an inserted benzene ring were found that a dipolar (5-tetrazolylio) phenolate structure contributes importantly to the ground state of the mesoions. On the contrary, a mesoion having an inserted anthracene ring is a less polar compound, anthraquinone methide structures being dominant in its ...
