Intramolecular Hydrogen Bonding in Structural Conformers of 2-Amino Methylene Malonaldehyde: AIM and NBO Studies

摘要

The molecular structure and intramolecular hydrogen bond energies of 44 conformers of 2-Amino methylene malonaldehyde were investigated at MP2 and B3LYP levels of theory using the standard 6-311++G** basis set and AIM and NBO analysis. The calculated geometrical parameters and conformational analysis in gas phase show that the closed ring via intramolecular hydrogen bonded conformers of this compound are more stable than the other ones. Hydrogen bond energies for H-bonded conformers were obtained from the related rotamers method (RRM) and Schuster method, and also the nature of H-bonding of them has been investigated by means of the Bader theory of atoms in molecules, which is based on topological properties of the electron density. Delocalization effects can be identified from the presence of off diagonal elements of the Fock matrix in the NBO basis.