How Accurate is the SMD Model for Predicting Free Energy Barriers for Nucleophilic Substitution Reactions in Polar Protic and Dipolar Aprotic Solvents?
| Autor: | Josefredo R. Pliego, Carlos M. Silva, Calink I. L. Santos, Elizabeth L. M. Miguel |
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| Rok vydání: | 2016 |
| Předmět: |
solvent effect
010405 organic chemistry aromatic nucleophilic substitution Thermodynamics General Chemistry M11 functional 010402 general chemistry 01 natural sciences Polarizable continuum model ion solvation continuum solvation model 0104 chemical sciences Solvent chemistry.chemical_compound Dipole chemistry Computational chemistry Nucleophilic substitution Polar Methanol Solvent effects Root-mean-square deviation |
| Zdroj: | Journal of the Brazilian Chemical Society v.27 n.11 2016 Journal of the Brazilian Chemical Society Sociedade Brasileira de Química (SBQ) instacron:SBQ Journal of the Brazilian Chemical Society, Volume: 27, Issue: 11, Pages: 2055-2061, Published: NOV 2016 |
| ISSN: | 0103-5053 |
| DOI: | 10.5935/0103-5053.20160095 |
| Popis: | In the past seven years, the SMD (Solvent Model Density) method has been widely used by computational chemists. Thus, assessment on the reliability of this model for modeling chemical process in solution is worthwhile. In this report, it was investigated six anion-molecule nucleophilic substitution reactions in methanol and dipolar aprotic solvents. Geometry optimizations have been done at SMD/X3LYP level and single point energy calculations at CCSD(T)/TZVPP + diff level. Our results have indicated that the SMD model is not adequate for dipolar aprotic solvents, with a root of mean squared (RMS) error of 5.6 kcal mol-1, while the Polarizable Continuum Model (PCM) method with the Pliego and Riveros atomic cavities has led to RMS error of only 3.2 kcal mol-1. For methanol solvent, the SMD method has a RMS error of 3.0 kcal mol-1. The classical protic to dipolar aprotic solvent rate acceleration effect was not predicted by the SMD model for the tested systems. |
| Databáze: | OpenAIRE |
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