Hybrid Salt–Cocrystal Solvate: p-Coumaric Acid and Quinine System

Abstract

A hybrid salt–cocrystal methanol water solvate of p-coumaric acid (p-CA) and quinine (Q) with unexpected stoichiometry was prepared by the slow evaporation technique. The crystals were analysed using single crystal X-ray diffraction. The structure was solved in the monoclinic space group P21 with unit cell dimensions: a = 6.4061(4) A, b = 26.232(2) A, c = 10.9639(8) A and β = 103.707(2)°. The asymmetric unit contains one quininium cation, one p-coumarate anion and one molecule of p-CA, with water and methanol molecules playing a bridging role in the crystal structure. The thermal analyses of the crystals are reported together with kinetics of desolvation for the loss of methanol. A hybrid salt–cocrystal solvate whereby the asymmetric unit contains one quininium cation, one p-coumarate anion, one molecule of p-coumaric acid, with water and methanol molecules playing a bridging role in the crystal structure.