Thio acid

Only a few meta acids are known, these generally being polymerized 

An alternate system is often used in naming the polymeric acids present in fuming sulfuric acid (see p. 294). 

Thio acids and their salts are formally derived from oxygen acids or their salts by replacement of one or more oxygen atoms with sulfur  

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DAKIN WEST Acylation An acylative decartxixylation of o-amino acids or o-thio acids. 

Thio-salz, n. thio salt, -saure, /. thio acid. 

For a review of the addition of thio acids, see Janssen, M.J. in Patai The Chemistry of Carboxylic Acids and Esters Wiley NY, 1969, p. 720. 

Toluenesulfinic acid and its salts have been prepared by three general methods (1) The reduction of the sulfonyl chloride. The reagents which have been used for this arc sodium amalgam,1 zinc dust in alcohol or water,2 sodium sulfite,3 sodium sulfide,4 potassium hydrosulfide 5 (the thio acid being first formed) and sodium arsenite.6 (2) From toluene by the Friedel and Crafts reaction, using either sulfur dioxide and hydrogen chloride 7 or sulfuryl chloride.8 (3) From -toluidine by diazotization and... 

The stereochemistry of optically active phosphorus thio-acids has been reviewed2 and published lectures have covered such topics as phosphate and phosphonate compounds based on adamantane3 and AW-dihalogeno-amides of phosphoric acids.4... 

The pyridinium chlorochromate (PCC) oxidations of pentaamine cobalt(III)-bound and unbound mandelic and lactic acids have been studied and found to proceed at similar rates.Free-energy relationships in the oxidation of aromatic anils by PCC have been studied. Solvent effects in the oxidation of methionine by PCC and pyridinium bromochromate (PBC) have been investigated the reaction leads to the formation of the corresponding sulfoxide and mechanisms have been proposed. The major product of the acid-catalysed oxidation of a range of diols by PBC is the hydroxyaldehyde. The reaction is first order with respect to the diol and exhibits a substantial primary kinetic isotope effect. Proposed acid-dependent and acid-independent mechanisms involve the rapid formation of a chromate ester in a pre-equilibrium step, followed by rate-determining hydride ion transfer via a cyclic intermediate. PBC oxidation of thio acids has been studied. ... 

Nickel tetracarbonyl may be prepared in the laboratory by the Hieber process, a disproportion reaction of several nickel compounds of organic thio acids, such as nickel(II) phenyldithiocarbamate, (CeHs— NH—C(=S)—S)2Ni, with carbon monoxide under controlled conditions. In such disproportionation reactions, the divalent nickel ion converts to a tetravalent nickel complex (Hieber. H. 1952. Z.anorg.Chem., 269, pp. 28). The overall reaction is ... 

Thio-acids and Salts Derived from Carbon Disulphide. 

Salts and esters of the intermediate thio-acids are known, being prepared from carbon disulphide or carbon oxysulphide. 

Table 13.21) or from amides by treatment with Lawesson s reagent. Thioamides can also be prepared on cross-linked polystyrene by the addition of H2S to nitriles (Entry 5, Table 13.21), by thiocarbamoylation of resin-bound organolithium compounds (Entry 6), or by the acylation of amines with reactive thio acid derivatives (Entry 7, Table 13.21). 

The oxygen is replaced by sulphur with the formation of mercaptans and thio-acids. 

Oxidation of thio acids by tetrabutylammonium tribromide showed Michaelis-Menten-type kinetics with respect to the thio acid. The effect of solvent composition was analysed using the Grunwald-Winstein equation. A mechanism involving the formation of an intermediate complex in the pre-equilibrium and its subsequent decomposition in a slow step is proposed.129... 

SULFUR COMPOUNDS MERCAPTANS,THIOPHENOLS THIO ACIDS... 

Thio acids have already been defined (Chap. 18) as acids related to their parent oxyacids by replacement of one or more oxygen atoms by sulfur. Most thio acids themselves are unstable, but their salts are stable and some (particularly the thiosulfates and thiocyanates) are quite familiar. Organic derivatives of monothiophosphoric acid, (HO)3PS, have recently found application as insecticides. 

Thiosulfuric acid is representative of a general class of acids, called thio acids or sulfo acids, in vhich one or more oxygen atoms of an oxygen add are replaced by sulfur atoms. For example, arsenic penta-sulfide dissolves in a sodium sulfide solution to form the thioarsenate ion, AsS -----, completely analogous to the arsenate ion, AsO ------- ... 

Sodium thiosulfate the thiosulfate ion the tetrathionate ion thio acids (sulfo... 

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