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

Abstract

13C and 1H NMR spectral parameters are investigated for 13CH 3Br in gaseous matrices. It is found that both the 13C and 1H chemical shifts of 13CH 3Br 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 13C and 1H magnetic shielding constants and 1 J(CH) spin–spin coupling are obtained for an isolated 13CH 3Br 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.