Conformational Analysis of N-Alkyl-N-[2-(diphenylphosphoryl)ethyl]amides of Diphenylphosphorylacetic Acid: Dipole Moments, IR Spectroscopy, DFT Study
| Autor: | Oleg I. Artyushin, N. A. Bondarenko, Yana A. Vereshchagina, Denis V. Chachkov, Anastasiia Kuznetsova |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Steric effects carbamoylphosphine oxides Organic Chemistry Substituent conformational analysis Pharmaceutical Science phosphorylated acetamides DFT calculations Medicinal chemistry Analytical Chemistry dipole moments chemistry.chemical_compound QD241-441 chemistry Chemistry (miscellaneous) Intramolecular force Amide Drug Discovery Molecular Medicine Molecule Physical and Theoretical Chemistry Methylene Conformational isomerism Alkyl |
| Zdroj: | Molecules Volume 26 Issue 16 Molecules, Vol 26, Iss 4832, p 4832 (2021) |
| ISSN: | 1420-3049 |
| DOI: | 10.3390/molecules26164832 |
| Popis: | Experimental and theoretical conformational analysis of N-methyl-N-[2-(diphenylphosphoryl)ethyl]diphenylphosphorylacetamide, N-butyl-N-[2-(diphenylphosphoryl)ethyl]diphenylphosphorylacetamide, and N-octyl-N-[2-(diphenylphosphoryl)ethyl]diphenylphosphorylacetamide was carried out by the methods of dipole moments, IR spectroscopy, and Density Functional Theory (DFT) B3PW91/6-311++G(df,p) calculations. In solution, these N,N-dialkyl substituted bisphosphorylated acetamides exist as a conformational equilibrium of several forms divided into two groups—with Z- or E-configuration of the carbonyl group and alkyl substituent, and syn or anti arrangement of the phosphoryl-containing fragments relative to the amide plane. The substituents at the phosphorus atoms have eclipsed cis- or staggered gauche-orientation relative to the P=O groups, and cis orientation of the substituents is due to the presence of intramolecular H-contacts P=O...H−Cphenyl or p,π conjugation between the phosphoryl group and the phenyl ring. Preferred conformers of acetamides molecules are additionally stabilized by various intramolecular hydrogen contacts with the participation of oxygen atoms of the P=O or C=O groups and hydrogen atoms of the methylene and ethylene bridges, alkyl substituents, and phenyl rings. However, steric factors, such as a flat amide fragment, the bulky phenyl groups, and the configuration of alkyl bridges, make a significant contribution to the realization of preferred conformers. |
| Databáze: | OpenAIRE |
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