DFT analysis of supra-molecular assemblies of substituted 4H-pyran derivatives

Abstract

This manuscript reports a theoretical characterization of two substituted pyran derivatives i.e. ethyl 6-amino-5-cyano-2-methyl-4-phenyl-4H-pyran-3-carboxylate 1 and ethyl 6-amino-5-cyano-2-methyl-4-(3-nitrophenyl)-4H-pyran-3-carboxylate 2 using DFT calculations. In particular the interesting supra-molecular assemblies that are formed in the solid state of compounds 1 and 2 have been analyzed using the QTAIM computational tool. In both compounds, in addition to classical H-bonds and π–stacking interactions, unconventional π–hole interactions that involve one of the double bonds of the six membered rings have been analyzed. This double bond is significantly polarized due to its special substitution with one electron withdrawing (CN) and one electron donating (NH2) groups.