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 b = 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.