The temperature dependence of the deuterium quadrupole coupling constant and the molecular rotational correlation time in liquid methanol

Temperature dependent experimental measurements of the methanol OH proton chemical shift and the OD deuterium relaxation time for neat methanol were made over the liquid range 200–340 K. From these data values for the deuterium quadrupole coupling constant X D and the molecular rotational correlation time τc, for the OD vector were obtained, X D was found to vary from 196kHz at 200 K to 215 kHz at 340 K, while τc varied from 65.0 ps to 3.0 ps over the same range. Using τc and the liquid viscosity, the size of the supramolecular hydrogen bonded clusters present in the liquid was found to range from 0.25 nm3 at 200 K to 0.24 nm3 at 340 K.