Experimental and theoretical determination of the stable conformation of α,α,2,6-tetrachlorotoluene

The stable conformation of α,α,2,6-tetrachlorotoluene molecule is determined at low temperature by analysis of the proton spectra with natural abundance satellites C-13, and also of 1H and 13C spectra, both in isotropic as well as in oriented solvents. The analysis of the 1H and 13C NMR data, including 2D correlation spectroscopy by the combination of homo- and hetero-nuclear experiments COSY, HMQC and HMBC in isotropic solvent is established. The experimental data are further supported by theoretical quantum chemistry calculations. The correct assignment of chemical shift of carbon atoms was revisited with the help of 2D spectra. We conclude that the hydrogen atom of the methylene dichloride functional group lies in the plane of the benzene ring.