Centrosymmetric resonance-assisted intermolecular hydrogen bonding chains in the enol form of β-diketone: Crystal structure and theoretical study
Arquivos
Data
2016-07
Título da Revista
ISSN da Revista
Título de Volume
Editor
Journal of Molecular Graphics and Modelling
Resumo
Isobenzofuran-1(3H)-ones (phtalides) are heterocycles that present a benzene ring fused to a γ-lactone functionality. This structural motif is found in several natural and synthetic compounds that present relevant biological activities. In the present investigation, the 3-(2-hydroxy-4,4-dimethyl-6-oxocyclohexen-1-yl)isobenzofuran-1(3H)-one was characterized by single-crystal X-ray analysis. In the crystal structure, there are two molecules per asymmetric unit. One of them exhibits resonance assisted hydrogen bonds (RAHBs). Semi-empirical and DFT calculations were performed to obtain electronic structure and π-delocalization parameters, in order to better understand the energy stabilization of RAHBs in the crystal packing of the studied molecule. The structural parameters showed good agreement between theoretical and experimental data. The theoretical investigation revealed that the RAHBs stabilization energy is directly related to the electronic delocalization of the enol form fragment. In addition, RAHBs significantly affected the HOMO and charge distribution around the conjugated system.
Descrição
Palavras-chave
Resonance assisted hydrogen bonds (RAHBs), X-ray structure, Semi-empirical and DFT calculations, Phtalides, Isobenzofuranones