Hirshfeld Surface Analysis of Stable and Metastable Polymorphs of Vanillin

Abstract The intermolecular interactions and the properties of voids present in the stable Form‐I and metastable Form‐II polymorphs of vanillin, a significant pharmaceutical and food material, are investigated through Hirshfeld surface analysis. Form‐I and Form‐II polymorphs of vanillin are separately grown through a template‐induced heterogeneous nucleation process from aqueous solution in the absence and presence of nickel foam as template and their structural parameters are obtained through single crystal X‐ray diffraction (SCXRD) analysis. With this SCXRD data as input, the intermolecular interactions within the grown polymorphs are analyzed by Hirshfeld surface analysis with detailed finger print plot and the area, volume, and percentage of voids present inside the polymorphic structures are identified through the isosurface of the spherical promolecular electron density. The 2D finger print analysis of each of the polymorphs reveals that besides the (H─H) interaction, the (O─H) interaction contributes more to the generation of polymorphs. Furthermore the percentage of volume occupied by the voids in the Form‐I and Form‐II are found to be 11.55% and 19.92%, respectively.