Back to Search Start Over

Conformational Analysis of N-Alkyl-N-[2-(diphenylphosphoryl)ethyl]amides of Diphenylphosphorylacetic Acid: Dipole Moments, IR Spectroscopy, DFT Study

Authors :
Oleg I. Artyushin
N. A. Bondarenko
Yana A. Vereshchagina
Denis V. Chachkov
Anastasiia Kuznetsova
Source :
Molecules, Volume 26, Issue 16, Molecules, Vol 26, Iss 4832, p 4832 (2021)
Publication Year :
2021
Publisher :
Multidisciplinary Digital Publishing Institute, 2021.

Abstract

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.

Details

Language :
English
ISSN :
14203049
Database :
OpenAIRE
Journal :
Molecules
Accession number :
edsair.doi.dedup.....2fbbe8ea0ba26dbf47b7c7729374ce66
Full Text :
https://doi.org/10.3390/molecules26164832