Three-co-ordinate sulphur

Three-co-ordinate sulphur. The most inorganic example has been the study of the kinetics and mechanism of hydrolysis of dithionites. Kinetics of attack of iodide and of thiourea at the 55 -dimethylsulphinium cation (M62S-NH2+) in water and in aqueous dimethyl sulphoxide indicate pre-equilibrium protonation followed by a rate-determining associative process. The overall activation entropy is negative. Nucleophilic substitution, by vinyl-lithium, at the triphenylsulphonium cation (PhaS ) is also associative. Indeed the species (30) is an intermediate rather than a transition state. Comparison of the stereochemical courses of reactions at tetrahedral phosphorus and at three-co-ordinate sulphur, which is 

Grignard synthesis of optically active sulphoxides has now been fully 

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A review of nucleophilic substitution at three-co-ordinate sulphur has been published. The acid-catalysed hydrolysis of (CF3CH20)2S0 occurs by a bimolecular process. Nucleophilic attack on SFgX (X=C1 or Br) and CF3SF4CI appears to occur on the sulphur rather than the non-fluoro halogens. 

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