Structures and energies of various isomers of dithionous acid, H2S2O4, and of its anion HS2O4(super - 1)

The energies and structural properties of various isomers of the dithionous acid, H2S2O4, and of its anion, HS2O4(super - 1), were investigated via ab initio molecular orbital calculations. The hypothetical O3SSOH(super -) was identified as the lowest energy isomer for the (H,O4,S2)(super -) anion. On the other hand, the cagelike dithionous acid molecule (HO)O2SSO2(OH) was stabilized by two very strong intramolecular hydrogen bonds, and its homolytic dissociation at the SS bond has a strong endothermic nature.