Electric dipole moment of sulfuric acid from Fourier transform microwave spectroscopy

The electric dipole moment of H2SO4 in the gas phase has been measured Using pulsed-nozzle Fourier transform microwave spectroscopy. Ninety one Stark-shifted frequencies at a series of electric field strengths have been recorded for the 1(10) <- 0(00) transition. The total molecular dipole montent (mu(tot) = mu(c)) was determined to be 2.9643(67) D. This is approximately 0.24 D greater than the previous literature value obtained from similar measurements on the 6(43) <- 5(33) transition. Both ab initio and DFT calculations using Dunning's aug-cc-pVnZ (n = D, T, Q, Q+d) basis sets concur with the present result. (C) 2007 Elsevier Inc. All rights reserved.