MASS SPECTROMETRY OF 8-HYDROXYQUINOLINE DERIVATIVES

Article abstract of DOI:10.1007/BF00508673

In contrast to the fragmentation of the corresponding alkyl aryl ethers, characteristic ⁺ and ⁺ fragments were observed in the fragmentation of 5-nitro(halo)-substituted 8-alkoxyquinolines.It was found by means of deuterium labeling that a hydrogen atom is split out primarily from the alkoxy group.It was demonstrated that an ⁺ fragment was from the ⁺ ion, which has a three-ring structure and quaternary nitrogen atom.The formation of an ⁺ fragment is characteristic for the fragmentation of 5(7)-nitro(halo)-substituted 8-hydroxyquinolines.The interrelationship between the intensities of the ⁺, ⁺, and ⁺ ion peaks and the protonation constants (pK_a) of the investigated compounds is discussed.