Negative ion mass spectral studies of polydentate Schiff base compounds: The formation of negative ions using chemical ionization conditions for Co(II), Ni(II) and Cu(II) complexes

Abstract

The negative ions mass spectra of polydentate Schiff base complexes with Co(II), Ni(II), and Cu(II) have been measured using chemical ionization conditions. Methane, methane-d 4 and isobutane were used as the reagent gases. Molecular negative ions were detected for all complexes. Secondary ions produced via ion/molecule reactions were noted for complexes with Co(II) and for some complexes with Ni(II). Since no reagent gas negative ions were detected, it is reasoned that the ion/molecule reactions occur by interaction of the metal complex molecular negative ion with the neutral reagent gas. For Cu(II) complexes only molecular negative ion and fragment ions were detected. It is suggested that electron configuration at the metal ion is a significant controlling factor in these reactions.