Theoretical Study of the Structural, Electronic Properties and GIAO 1H-NMR, 13C-NMR and the Effect of Substitutes on the Succinimide

Abstract

The calculations of Substituted Succinimide  (I, II, III) were carried out by using quantum chemical calculations. The optimized structures of the Compounds(I, II, III) were obtained by the Density functional theory DFT/B3LYP level of theory using the basis set 6-311++G(3d,3p). The study shown, the optimized structures of compounds (I, II, III) have the global minimum energy. Also  the dipole moment of compound (II) found to  have  high values compared with the Compounds (I, III). Global descriptors such as the MO energies of HOMO, LUMO levels, ΔE, electron affinity(A),ionization potential(I), hardness(η), electronegetivity(X), electrophilicity(ω) were determined and used to identify the differences in the stability and reactivity of compounds. In general calculated values lead to the conclusion that the stability of the compounds are I>II>III . On the other hand theoretical calculations  for 1H-NMR and 13C-NMR for compound( I) were carried out  and  compare with experimental data for compound (I) and predicate the 1H-NMR and 13C-NMR, Charge Density Distribution for compounds ( II, III). As well as the calculations show the effect of substitution on the ring leads to change of the bond length and angles.

 

Key Words: Substituted Succinimide, 1H-NMR and 13C-NMR spectra, DFT/B3LYP(6-311++G(3d,3p)).