This article reports quantum chemical calculations on sulphur trioxide (SO3) and its protonated analogues
) by employing six different computational methods. This covers the simple Hatree
Fock (HF) method, coupled cluster method, the Gaussian-4 (G4) compound method amongst others with
two different basis sets (6-311++G** and cc-pVDZ). Optimized geometries, bond distance, rotational
spectroscopy, dipole moment, proton affinity, vibrational spectroscopy and vibrational zero-point energy
are among the parameters that have been effectively and successfully computed for the three molecular
species under investigation. From the result obtained, there is a perfect agreement between the different
parameters investigated and the available experimental values. The high accuracy of the calculated results
gives a good image of the protonated analogues (HSO3
) which are deficient in experimental
data. The optimized geometry reveals that two of the three molecular species (i.e. SO3 and HOSO2
a trigonal geometry in all the computational methods employed while HSO3
analogue was discovered to
have a square planar geometry for MP2/6-311++G**, MP2/cc-pVDZ, CCSD/cc-pVDZ and G4
methods. We found that the proton affinities (PA) of SO3 was between 139.6 – 151.1 kcal/mol with
B3LYP/6-311++G** method predicting the best result and that S-protonation was by far the most
favoured site for proton attachment. Thus, the present quantum chemical studies have helped in bridging
the gap existing in the literature regarding this species since they are less studied experimentally due to
their unstable nature.
OKO EMMANUEL, G (2019). Computational studies of Sulphur trioxide and its protonated analogues. Afribary.com: Retrieved July 11, 2020, from https://afribary.com/works/computational-studies-of-sulphur-trioxide-and-8ts-protonated-analogues
GODWIN, OKO EMMANUEL. "Computational studies of Sulphur trioxide and its protonated analogues" Afribary.com. Afribary.com, 28 Oct. 2019, https://afribary.com/works/computational-studies-of-sulphur-trioxide-and-8ts-protonated-analogues . Accessed 11 Jul. 2020.
GODWIN, OKO EMMANUEL. "Computational studies of Sulphur trioxide and its protonated analogues". Afribary.com, Afribary.com, 28 Oct. 2019. Web. 11 Jul. 2020. < https://afribary.com/works/computational-studies-of-sulphur-trioxide-and-8ts-protonated-analogues >.
GODWIN, OKO EMMANUEL. "Computational studies of Sulphur trioxide and its protonated analogues" Afribary.com (2019). Accessed July 11, 2020. https://afribary.com/works/computational-studies-of-sulphur-trioxide-and-8ts-protonated-analogues