Tungstates, thio

Tungstates, decachlorooxydi-, 3, 990 Tungstates, nonahalodi-, 3, 999 Tungstates, thio-. 3, 982 Tungstate X, 3,1034 Tungsten biology, 6, 667... 

The infrared, Raman, visible and ultraviolet spectra of the thiomolybdate and thio-tungstate species have been examined in detail and are given in several of the papers cited. The Mo-S and W-S stretching frequencies in these compounds are in the vicinity of 480—450 cm-1. The infrared and Raman spectra of some thiochalco-genide anions reported by Muller200 are given in Tables 10 and 11. 

Various sulphides of the chromium elements exist, and these, particularly in the case of molybdenum and tungsten, combine with alkalies and alkali sulphides to produce thio-salts thus, thio-tungstates of the types R jW03S, R WOjSj, R WOSg, and R WS, have been prepared. 

Oxidation from thiol through to sulphonic acid in one step can be accomplished by peracids [233], or activated H2O2 systems, including molybdates, tungstates [234] and ferrous salts [235] among the catalytic activators. Isethionic acid can be prepared from 2-thioethanol [236], and sulpho esters from thio esters [237]. 

Under more acidic conditions, condensation of the tungstate ion proceeds to the hydrated oxide WOv/tHiO. However, there is no direct stmctural relationship between the solid and the polyanion. 

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