Structure Determination of Multicomponent ReactionProduct (2H-Quinolizine) by Using of Computational Method

Computational studies have been carried out at DFT-B3LYP/6-31G and 6-31++G** level of theory on the structural and spectroscopic properties of 2H-quinolizine. 2H-quinolizine obtain from fourcomponent reaction of the zwitterion generated from pyridine and diisopropylcarbodiimide with electrondeficient dimethyl acetylenedicarboxylat. The optimized geometry of this compound and its bonding characteristics, and NMR Spectra as well as charge have been calculated and analyzed.The influence of the bulk solvent was investigated at the B3LYP/ 6-31++G** level using polarizable continume model. The results of this study show that the 4 is more stable than the 11 in the gas and solvent phase, due tointra molecular hydrogen bonding. Also, natural bond orbital (NBO) analysis shows that there is long π- electron delocalization in compound 4 in comparison to compound 11 which leads to the stabilization of the compound 4 in relative to compound 11. There is a good agreement between the experimental and calculated chemical shifts in 13C and 1H-NMR.

کلیدواژه ها:

2H-Quinolizine ، Multi-component reaction ، Zwitterion ، solvent-free conditions ، Characterization ، Quantum chemical calculation