13C and 1H nuclear magnetic shielding and spin–spin coupling constants of 13C-enriched bromomethane in the gas phase

Abstract 13 C and 1 H NMR spectral parameters are investigated for 13 CH 3 Br in gaseous matrices. It is found that both the 13 C and 1 H chemical shifts of 13 CH 3 Br are linearly dependent on solvent density. Similar dependence is also detected for one-bond spin–spin coupling, 1 J (CH). For the first time the 13 C and 1 H magnetic shielding constants and 1 J (CH) spin–spin coupling are obtained for an isolated 13 CH 3 Br molecule together with the coefficients responsible for solute–solvent molecular interactions in gaseous matrices. The present experimental results confirm the accuracy of some recent ab initio calculations of nuclear magnetic shielding performed for bromomethane.