Disulfonyl carbon acids – synthesis, spectroscopic and structural studies – a review

The subject of carbon acids activated by two sulfonyl groups is reviewed. It will be shown that the studied compounds are relatively strong acids that have their importance in organic chemistry. The structure and reactivity of the products of the deprotonation reaction are also described. Structural studies using X-ray and spectroscopic methods such as IR, NMR or MS give more information about their proton donor properties. They are supplemented by charge distribution research in these carbanions using empirical evaluation and electron density ab initio calculation. A comparison of the results obtained for the title compounds with data obtained for other carbon acids activated by nitro or cyano groups is presented.