New sulfonyl derivatives of 2,2-diphenyl-1-picrylhydrazyl and their supramolecular complexes with crown ethers or kryptands

The synthesis of mono- and di-sulfonates 1 and 2 derived from DPPH was opti mised (their notation is NaOSO2- DPPH and (NaOSO2)(2)-DPPH, respectively). The pK(a) values of the corresponding hydrazines 3 and 4 were determined. W ith crown ether 18-C-6, hydrophobic supramolecular complexes are formed by 3 and 4. The sodium monosulfonate 3 reacts with thionyl chloride yielding t he sulfochloride ClSO2-DPPH-H (5). With alcohols or amines, 5 reacts readil y leading to all:yl esters and sulfonamide derivatives, respectively: thus, valine afforded a well-characterized compound, and the corresponding free radical may be used as a spin label or as a colored redox indicator for pep tide chemistry. Similarly, 4-aminoantipyrine forms a sulfonamide. The new c ompounds were characterised by elemental analysis, IR, UV-VIS, NMR and ESR spectroscopy, and by their complexation and transport data.