F-19 NMR-STUDY OF RELATIVE POLARITIES AND REACTIVITIES OF N-H, N-HG, AND N-AU BONDS IN 2-(4-FLUOROPHENYL)BENZIMIDAZOLE AND ITS PHHG AND PH(3)PAU DERIVATIVES IN INTERMOLECULAR EXCHANGE

It has been shown by the F-19 NMR method that the relative polarities of nitrogen-element bonds in 2-(4-fluorophenyl)benzimidazole and its P hHg and PPh(3)Au derivatives increase in the order N-H < N-Hg ( N-Au. Intermolecular exchange reactions of hydrogen-mercury, hydrogen-gold, and mercury-gold types in binary mixtures of these compounds have been studied by dynamic F-19 NMR. It has been found that these reactions o ccur by a bimolecular associative mechanism and that the N-H bond is s ubstantially less reactive than the N-Hg and N-Au bonds, which have id entical reactivities within the limits of sensitivity of the method us ed.