Hindered Rotation in Some Organic Dithiocarbamates

Abstract

Hindered rotation in alkyldithiocarbamates of the type RR′NC(= S)SR″ [R, R′, R″ = Me, Me, Et (1); PhCH₂, Me, Et (2); PhCH₂, H, Et (3); PhCH₂, H, Me (4) and O(CH₂CH₂)₂, Et (5)′ has been investigated using variable-temperature ¹H NMR spectroscopy in CDCl₃, C₆D₆, and DMSO-d₆ solutions. Rotational parameters were calculated by the coalescence temperature method. Nitrogen substituent effects on the free energy of activation and on the equilibrium constant of unsymmetrical conformers at room temperature are discussed.

GRAPHICAL ABSTRACT

Keywords:

• Conformational analysis
• dithiocarbamates
• hindered rotation
• NMR spectroscopy

Acknowledgments

We thank J.-C. Lartigue (CESAMO, University Bordeaux 1) for his kind and efficient assistance in recording variable-temperature ¹H NMR spectra, and the DGRST for financial support of this work. E-mail: [email protected]