Structure determination of SO2 by electron diffraction

Abstract
A determination of the structural parameters of gaseous sulfur dioxide has been made with counting electron diffraction apparatus at an electron energy of 54.157 keV over the s range from 10 to 30 Å−1. The structure parameters are found to be ra(S–O) = 1.4343(3) Å, ra(O⋅⋅O) = 2.4718(28) Å, l(S–O) = 0.0359(10) Å, l(O⋅⋅O) = 0.0561(31) Å, and ∢ OSO = 119.5 °(0.3 °). The quoted uncertainties are 2σ. Since the experimental results agree very well with the spectroscopic and theoretical structure parameters, it is proposed that SO2 be accepted as the standard reference molecule in place of CO2.