CE/ES-MS ANALYSIS ON MACROCYCLIC SCHIFF BASES DERIVED FROM A SODIUM TEMPLATE CYCLOCONDENSATION OF 2,6-DIFORMYL-4-METHYLPHENOL WITH ALKYLDIAMINES

Abstract The template reaction of sodium 2,6-diformyl-4-methylphenolate with alkyl diamines H2NRNH2 [R = (CH2)n, n = 4, 5, 6] led to the production of macrocyclic Schiff bases which were characterized by elemental analyses, IR and proton NMR spectra. Positive ion fast atom bombardment (FAB) and electron spray ionization (ES) mass spectroscopic investigations on the above products showed the presence of a [3 ± 3] (H3L3) cyclocondensation mode in addition to the common [2 ± 2] (H2L2) mode. The product in a typical reaction was analysed by capillary electrophoresis (CE) coupled to a mass spectrometer (MS) via an electrospray (ES) ionization interface, confirming the independent formation of both tetraimine and hexaimine macrocycles as a mixture of Na2L2 and Na3L3.