Liquid Nicotine Tamed in Solid Forms by Cocrystallization

Abstract

We address the problem of stabilizing liquid nicotine in solid forms at ambient conditions by cocrystallization. The design of cocrystals forms of nicotine has been approached by analyzing its molecular electrostatic potential. An intriguing aspect of nicotine lies in the fact that its crystal structure has never been reported in literature and this peculiarity may be ascribed to the liquid-glass transition that occurs when nicotine is supercooled under its melting point (-79°C). Despite nicotine was considered a rigid molecule, its glass forming attitude could be due to a certain extent of conformational variability, which has been assessed by the conformer search of the CCDC software. Based on these considerations, three coformers have been identified and their crystal structure shows that nicotine adapts to the packing features dictated by the coformers. The tool of packing energy frameworks has been used to discuss the stabilization of the cocrystals.