arXiv subjects

Michael Kiselev

Publications and source records attributed to Michael Kiselev.

2 recordsLinked to original sources

arXiv2020

Exposing Hidden Alternative Conformations of Small Flexible Molecules in 2D NMR Spectroscopy Using 1H-15N HMBC

Two-dimensional 1H-15N HMBC NMR spectra of a well-known anticonvulsant-carbamazepine-dissolved in chloroform, recorded on an NMR spectrometer and obtained from quantum-chemical calculations prove the existence of hidden conformers in saturated solutions. A weaker influence of ring currents was revealed for the hidden conformation of carbamazepine dissolved in saturated solution, which provides a simple approach for discovering hidden conformations. Hidden conformers were found in three different solvents: dimethyl sulfoxide, chloroform, and dichloromethane.

physics.chem-ph↗

arXiv2020

High-pressure NMR spectroscopy in studies of the conformational composition of small molecules of ibuprofen in supercritical carbon dioxide

An experimental approach in conducting NMR measurements at supercritical parameters of state is discussed. A novel design of the high-pressure NMR cell was developed which allowed eliminating the field inhomogeneity and, thus, increasing the sensitivity of the experiment at the supercritical state. Analysis of the MD simulations and NMR data showed that two conformers of ibuprofen dominate in the solution in supercritical CO2 along the critical isochore 1.3 \r{ho}cr(CO2). Conformer populations calculated from MD simulations and from NMR spectra agree with each other

physics.chem-ph↗