Electric field N.M.R.

Abstract

Application of a strong de electric field to solutions of apolar molecules in an apolar solvent leads to partial orientation of the molecules. This orientation could be detected by N.M.R. spectroscopy through the anisotropic spin interactions that show up in the spectra. Subsequent analysis of the spectrum leads to information about the static electric polarizability tensor (a). The electric field N.M.R. (EFNMR) method was applied to measure, from the ²H EFNMR spectrum of naphthalene-d₈, the anisotropy of a (i.e. Δα), and asymmetry (δα). The result is: 7·1 ± 0·3 and -(4·4 ± 0·5) × 10^-24 cm³ for Δα and δα respectively. For triphenylene-d₁₂ the value of Δα is measured to be -(14·4 ± 1·4) × 10^-24 cm³. The results from the EFNMR method and from other methods are compared and discussed