Tanusri Dey, Soumen Ghosh, Somnath Ghosh
Jul 15, 2015
Citations
0
Influential Citations
5
Citations
Journal
Journal of Molecular Structure
Abstract
Abstract Four 5-arylidene derivatives of Meldrum’s acid, 5-(4-chlorobenzylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione (2), 5-(3-hydroxybenzylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione (3), 5-(3,4-dimethoxybenzylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione (4) and 5-(2,4-dimethoxy benzylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione (5) have been synthesized and their crystal structures have been determined using single crystal X-ray diffractometry for 2, 4 and 5 and X-ray powder diffraction for 3. The nature of intermolecular interactions in 2–5 has been analyzed through Hirshfeld surfaces and 2D fingerprint plots. The DFT optimized molecular geometries in 2–5 agree closely with those obtained from the crystallographic studies. The crystal packing in 2–5 exhibits an interplay of O H⋯O, C H⋯O, C H⋯Cl and C H⋯π (arene) hydrogen bonds and π⋯π interactions, which assemble molecules into three-dimensional architecture in 2, 3 and 5 and two-dimensional framework in 4. The Hirshfeld surface analyses of 2–5, Meldrum’s acid (1) and a few related 5-arylidene derivatives of Meldrum’s acid retrieved from the Cambridge Structural Database (CSD) indicate that about 85% of the Hirshfeld surface area (72% in 2 where H⋯Cl contribution is about 13%) in this class of compounds are due to H⋯H, O⋯H and C⋯H contacts. The HOMO–LUMO energy gap (>2.2 eV) in 2–5 indicates a significant degree of internal charge transfer within the molecule.