Structural and Theoretical Studies of Mesoionic Benzo[ <i>c</i> ]tetrazolo[2,3- <i>a</i> ]cinnolinium Olate Solvates

Benzo[c]tetrazolo[2,3-a]cinnolinium-2-olate, a Class 5 mesoionic species, was synthesized and cocrystallized with various small molecules, including water, methanol, formic acid, acetic acid, propionic acid, and trifluoroacetic acid. The nature of the hydrogen bonding interactions was elucidated through single-crystal X-ray diffraction, quantum-chemical calculations, thermogravimetric and differential thermal analyses, and examination of the relationship between aromaticity and hydrogen bonding. In addition, graph-set and geometric analyses were performed to evaluate other noncovalent interactions present within these crystalline assemblies.