Лако-красочные материалы — производство

The fragmentation of tetrazolium salts under electron impact seems to follow characteristic paths. 5-Methy1-2,3-diphenyl tetrazolium (124) shows, in addition to the parent ion peak, peaks corresponding to the phenyl diazonium fragment and the complementary ion at m/z 132. At higher ionization energies, a strong peak at m/z 91 corresponding to the elimination of acetonitrile from the parent ion is observed (Scheme 17).211 By contrast, the mass spectrum of 1,4,5-trisubstituted tetrazoliums, e. g., 125 shows strong peaks corresponding to the nitrilium ions 126 and 127 as shown in Scheme 18).212 The mass spectrum of mesoionic tetrazoliums shows only 10% of the intact parent ion peak and mostly peaks corresponding to diazonium ions.213 With thermospray mass spectrometric techniques, bistetrazolium salts form intact cations as a base peak.214