Transition metal complexes with a polydentate Schiff base derived from 3-formylsalicylic acid and 1,2-bis(o-aminophenylthio)ethane

The reaction of 3-formylsalicylic acid with 1,2-bis(o-aminophenylthio)ethane yielded a Schiff base with eight donor centres N2S2O4 of which the inner compartment is of an N2S2O2 type and the outer is of the O2O2 type. The base forms several mononuclear homo- and hetero-dinuclear complexes: e.g. mononuclear Cu-II, Ni-II and dinuclear Cu-II, Ni-II, UO2VI complexes. Hetero-dinuclear complexes {[M]M'}, where M = the inner metal ion Cu-II, Ni-II and M' = the outer metal ion Pd-II, UO2VI are also reported. The complexes were characterised by elemental analyses, spectral, thermal and magnetic measurements. Dicopper and dinickel complexes exhibit subnormal magnetic moments showing spin pairing between two metal centres, via the phenolato oxygen, whereas other mono-copper and mono-nickel complexes (both mononuclear and hetero-dinuclear) show the expected magnetic behaviour for 1e and 2e, respectively. The e.s.r. spectra of copper complexes also support the above behaviour.