Oxyanions of Sulphur

A thermally populated triplet excited state of the triclinic form of (KS03)2N02 has been detected by e.p.r. and static susceptibility measurements. The crystal structure of HK2NO6S2 has been redetermined from three-dimensional neutron-diffraction data. The reaction of SO2 with molybdate ions in aqueous solution 

The oxidation products when 201 is used as a titrant against lead tetraacetate in glacial acetic acid have been identified as di- and tetra-thionates, whereas sulphate is the end product in titrations using 820 .  

The disproportionation of thiosulphate, trithionate, tetrathionate, and sulphite in acid solutions has been studied at moderate temperatures. Thiosulphate hardly decomposes in the absence of sulphuric acid, even at 150 °C, but decomposes readily in the presence of sulphuric acid at 70 °C, forming sulphur, tetrathionate, and sulphite. Trithionate decomposes to thiosulphate and sulphate at 70 °C, whereas tetrathionate decomposes only above 130 C. Sulphite undergoes disproportionation, giving thiosulphate and sulphate at 150 °C, and then sulphur and sulphate, accompanied by the intermediate formation of tetrathionate.  

An intramolecular exchange of sulphur in solid Na2S20s has been confirmed and improved rate constants have been measured. The mechanism of decomposition of dithionite in aqueous solutions has been studied. The decomposition can be described by the equations (30) and (31). The final composition of the 

2H2S2O4 S + 3SO2 + 2H2O 3H2S2O4 H2S + 5SO2 + 2H2O 

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Other Oxyanions of Sulphur. The effect of pressure on the dissociation of aqueous solutions of the bisulphate ion has been studied182 by measuring the Raman spectra of sulphate at 982 cm-1 and bisulphate at 1052 cm-1. An increase in the intensity of the sulphate peak was observed with increasing... 

Most organosulphur compounds for which structures have been reported are omitted from this chapter, since they are covered in the Organic Section. Most of the remaining crystal structures concern oxyanions of sulphur. 

There have been several reports on oxidation reactions by copper(ii)-poly(4-vinylpyridine) complexes such as those of L-ascorbic acid, oxyanions of sulphur, phenol derivatives, and the dimerization of acetylenes. ... 

Following a short review of early studies of the valence band of tetrahedral oxyanions of types X04" some recent results of this field are discussed. High resolution XPS measurements of the valence band of phosphorus and sulphur oxyanions made possible a rigorous test of various theoretical models. For DV-Xa cluster MO calculations, experimentally determined crystal structure information were used to set up realistic model clusters. In the case of the S04 cluster, the results of several model calculations ab initio, DV-Xa, hybrid models) are presented. From the comparison of these results a better understanding of the role of the contributions from different effects to the MO one-electron energies can be obtained. 

POr and PFe, the sulphur, chlorine, silicon, and aluminium analogues have been treated. New ab initio calculations have been reported on P04-,492 and data from X-ray emission and p.e.s. for several second-row oxyanions, including PO3-, give good agreement with the results of such computations.493... 

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