Motional dynamics in liquid 1,2,3,4-tetrahydro-5,6-dimethyl-1,4-methanonaph-thalene. Part 1. A new model compound for the investigation of anisotropic rotational diffusion and internal rotations by 13C spin–lattice relaxation data
Abstract
The hydrocarbon 1,2,3,4-tetrahydro-5,6-dimethyl-1,4-methanonaphthalene (1) was synthesized and characterized. The molecular structure of (1) is rigid and asymmetric. The molecules of (1) have at least one hindered rotating methyl group and a sufficient number of non-parallel C–H vectors. The 13C spin–lattice relaxation times and n.O.e. factors of (1) were measured and assigned to the corresponding carbon atoms. The dipolar 13C spin–lattice relaxation times n(T1DD) of non-methyl carbon atoms bearing directly attached protons (n is the number of these protons) are significantly different from each other, thus indicating the anisotropy of the molecular reorientation.