title: Molecular structure, spectral studies, intra and intermolecular interactions analyses in a novel ethyl 4-[3-(2-chloro-phenyl)-acryloyl]-3,5-dimethyl-1H-pyrrole-2-carboxylate and its dimer: A combined DFT and AIM approach.
abstract: A newly synthesized chalcone, Ethyl 4-[3-(2-chloro-phenyl)-acryloyl]-3,5-dimethyl-1H-pyrrole-2-carboxylate (ECPADMPC) has been characterized by (1)H NMR, (13)C NMR, UV-Vis, FT-IR, Mass spectroscopy and elemental analysis. Quantum chemical calculations have been performed by DFT level of theory using B3LYP functional and 6-31G(d,p) as basis set. The time dependent density functional theory (TD-DFT) is used to find the various electronic transitions within molecule. A combined theoretical and experimental wavenumber analysis confirms the existence of dimer. Topological parameters-electron density (ρ(BCP)), Laplacian of electron density (∇(2)ρ(BCP)), energetic parameters-kinetic electron energy density (G(BCP)), potential electron density (V(BCP)) and the total electron energy density (H(BCP)) at the bond critical points (BCP) have been analyzed by 'Atoms in molecules' AIM theory in detail. The intermolecular hydrogen bond energy of dimer is calculated as -12.3kcal/mol using AIM calculations. AIM ellipticity analysis is carried out to confirm the presence of resonance assisted intermolecular hydrogen bonds in stabilization of dimer. The analysis clearly depicts the presence of different kind of interactions in dimer. This dimer may work as model system to understand the H-bonding interaction in biomolecules. The local reactivity descriptor analysis is performed to find the reactive sites within molecule.
authors.affiliation: Department of Chemistry, University of Lucknow, Lucknow 226007, UP, India.
authors.forename: R N
authors.initials: RN
authors.lastname: Singh
authors.forename: Vikas
authors.initials: V
authors.lastname: Baboo
authors.forename: Poonam
authors.initials: P
authors.lastname: Rawat
authors.forename: Amit
authors.initials: A
authors.lastname: Kumar
authors.forename: Divya
authors.initials: D
authors.lastname: Verma
mesh_terms: D019281:Dimerization; D004583:Electrons; D019277:Entropy; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D011392:Proline / Q000031:analogs & derivatives* / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry*; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D014732:Vibration
chemical_list: D011758:Pyrroles; C575204:ethyl-4-(3-(2-chloro-phenyl)-acryloyl)-3,5-dimethyl-1H-pyrrole-2-carboxylate; C002986:2-pyrrolecarboxylic acid; D011392:Proline