| Theoretical investigation of solvent effects on the Mechanism of the Knoevenagel reaction using DFT calculations |
| کد مقاله : 1284-ICOC |
| نویسندگان |
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فرشته یعقوبی *1، اعظم شیری2 1دانشگاه بوعلی سینا- مجتمع آموزش عالی نهاوند 2دانشگاه ملایر-گروه شیمی آلی |
| چکیده مقاله |
| The reaction mechanism of 2-cyanoacetamide with benzaldehyde catalyzed by triethylamine (NEt₃) was investigated using Density Functional Theory (DFT) at the wB97XD/6-31++G** level. All reactants, intermediates, and transition states were fully optimized, and Gibbs free energies were calculated to evaluate the energetic profile of the reaction. The mechanism was analyzed in three media: gas phase, acetonitrile, and ethanol, employing the CPCM solvation model. The results indicate that in the gas phase the reaction is energetically unfavorable, as the transition state associated with cation–anion pair formation exhibits the highest Gibbs free energy among all phases. Solvent effects substantially reduce the energy barriers of intermediates and transition states, stabilizing charged species. Comparative analysis of the solvents shows that ethanol provides stronger stabilization than acetonitrile, yielding lower Gibbs free energies throughout the reaction pathway. Overall, the study demonstrates that the reaction is feasible only in polar solvents, with ethanol offering the most favorable energetic conditions for the reaction progression. |
| کلیدواژه ها |
| DFT, Knoevenagel, Gibbs Free Energy, Acetonitrile, Ethanol |
| وضعیت: پذیرفته شده |