Structural, spectroscopic (FT-IR, FT-Raman) and theoretical studies of the 1:1 cocrystal of isoniazid with p-coumaric acid

The 1:1 cocrystal of isoniazid (INH) with p-coumaric acid (pCA) has been prepared by slow evaporation method in methanol, which was crystallized in monoclinic P21/n space group having four molecules in the asymmetric unit. The cocrystal has been characterized by single crystal X-ray analysis, FTIR, FT Raman and DFT calculations. The crystal structure was stabilized by OHphenol⋯Npyridine, NH⋯OC, COOH⋯NH and CH⋯O hydrogen bonding interactions. The geometry optimized structure of the cocrystal at the B3LYP/6-31G(d,p) level of theory has been used to calculate the vibrational frequencies.