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

Ilya Khodov; Sergey Efimov; Michael Krestyaninov; Michael Kiselev

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arXiv · 2003.09608

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

Ilya Khodov·Sergey Efimov·Michael Krestyaninov·Michael Kiselev

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Abstract

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.

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Ilya Khodov, Sergey Efimov, Michael Krestyaninov, Michael Kiselev. 2020-03-21. Exposing Hidden Alternative Conformations of Small Flexible Molecules in 2D NMR Spectroscopy Using 1H-15N HMBC. https://arxiv.org/abs/2003.09608

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