C-13 and H-1 NMR spectral parameters are investigated for (CH3Br)-C-13 in gaseous matrices. It is found that both the C-13 and H-1 chemical shifts of (CH3Br)-C-13 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 C-13 and H-1 magnetic shielding constants and (1)J(CH) spin-spin coupling are obtained for an isolated (H3Br)-H-13 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. (C) 2007 Elsevier B.V. All rights reserved.