Determination of the dipole moment of H3N–SO3 in the gas phase

Abstract The dipole moment of the partially bonded molecule H 3 N–SO 3 has been measured by microwave spectroscopy in the gas phase. The value obtained, 6.204(11) D, is over 4 times the sum of the individual monomer moments. The results are discussed in the context of recent speculations as to the complex's role in the nucleation of atmospheric aerosols.