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The thiosulfate ion is tetrahedral at the central S atom. The thiosulfate ion has C 3v symmetry. The external sulfur atom has a valence of 2 while the central sulfur atom has a valence of 6. The oxygen atoms have a valence of 2. The S-S distance of about 201 pm in sodium thiosulphate is appropriate for a single bond.
In a thionoester, sulfur replaces the carbonyl oxygen in an ester. Methyl thionobenzoate is C 6 H 5 C(S)OCH 3. Such compounds are typically prepared by the reaction of the thioacyl chloride with an alcohol. [16] They can also be made by the reaction of Lawesson's reagent with esters or by treating pinner salts with hydrogen sulfide.
A chemical reaction involving the replacement of oxygen to sulfur is called thionation or thiation. Thio- can be prefixed with di- and tri- in chemical nomenclature. The word derives from Ancient Greek θεῖον (theîon) 'sulfur' (which occurs in Greek epic poetry as θέ(ϝ)ειον , théweion and may come from the same root as Latin fumus ...
Two polymorphs are known as pentahydrate. The anhydrous salt exists in several polymorphs. [2] In the solid state, the thiosulfate anion is tetrahedral in shape and is notionally derived by replacing one of the oxygen atoms by a sulfur atom in a sulfate anion. The S-S distance indicates a single bond, implying that the terminal sulfur holds a ...
Conversion of simple disulfides to thiosulfinates results in a considerable weakening of the S–S bond from about 47.8 to 28.0 kcal mol −1 for the S-S bond in PhS(O)SPh and from about 63.2 to 39.3 kcal mol −1 for the S-S bond in MeS(O)SMe, [14] with the consequence that most thiosulfinates are both unstable and quite reactive.
The advantages of this approach are that (i) thiosulfate is far less toxic than cyanide and (ii) that ore types that are refractory to gold cyanidation (e.g. carbonaceous or Carlin-type ores) can be leached by thiosulfate. One problem with this alternative process is the high consumption of thiosulfate, which is more expensive than cyanide.
The S−H bond in thiols is weak compared to the O−H bond in alcohols. For CH 3 X−H, the bond enthalpies are 365.07 ± 2.1 kcal/mol for X = S and 440.2 ± 3.0 kcal/mol for X = O. [ 21 ] Hydrogen-atom abstraction from a thiol gives a thiyl radical with the formula RS • , where R = alkyl or aryl.
Oxygen is present as compounds in the atmosphere in trace quantities in the form of carbon dioxide (CO 2) and oxides of nitrogen (NO x). The Earth's crustal rock is composed in large part of oxides of silicon (silica SiO 2, found in granite and sand), aluminium (aluminium oxide Al 2 O 3, in bauxite and corundum), iron (iron (III) oxide Fe 2 O