An N.M.R. investigation of tunnelling sidebands in dimethyl sulphide, 2-pentanone, 2-hexanone and 2-heptanone using double sideband irradiation

Publisher Website
Google Scholar
Abstract
Measurements have been made of the low temperature tunnelling frequencies of strongly hindered methyl groups in four samples; dimethyl sulphide, 2-pentanone, 2-hexanone and 2-heptanone; using the technique of double sideband irradiation. The temperature dependence of the proton spin lattice relaxation time for dimethyl sulphide has been measured and found to be anomalous. An explanation in terms of methyl coupling is suggested. A semi-quantitative electrical analogue model of double sideband irradiation is discussed and used to calculate the expected sensitivity of the method.