Mass spectral analysis of Schiff bases derived from 1,1,1-trifluoro-2,4-pentanedione and Bis(3,3′-aminopropyl)amine and bis(3,3′-aminopropyl)methylamine and their copper(II) and nickel(II) complexes

Mass spectra have been obtained for bis(5,5,5-trifluoro-4-oxopentan-2-N-propylene)amine, bis(5,5,5-trifluoro-4-oxopentan-2-N-propylene)methylamine, bis(5,5,5-trifluoro-4-oxopentan-2-N-propylene)aminocopper(II), bis(5,5,5-trifluoro-4-oxopentan-2-N-propylene)aminonickel(II), bis(5,5,5-trifluoro-4-oxopentan-2-N-propylene)methylaminocopper(II) and bis(5,5,5-trifluoro-4-oxopentan-2-N-propylene)methylaminonickel(II) using a Varian-MAT CH5 mass spectrometer. The first two compounds are seen to fragment primarily in the trimethylene chain γ to the middle nitrogen although fragmentation is seen at a variety of other sites as well. Lower molecular weight ions form a significantly larger fraction of the total ion intensity for the methylated middle nitrogen compound than for its non-methylated analog. In the metal complexes of these Schiff bases, the metal exerts its influence in two ways. The primary cleavage site inthe trimethylene bridge is β, rather than γ, to the middle nitrogen, and other fragments are produced which are ascribable to ligand to metal electron transfer.