Manganese Schiff's base complexes—I: Synthesis and spectroscopy of some anion complexes of (4-sec-butylsalicylaldehydeethylenediiminato) manganese(III)

Abstract

A series of new five-coordinate complexes of the type [Mn(BuSalen) X] where BuSalen is the tetradentate Schiff's base 4-sec-butylsalicylaldehydeethylenediimine and X equals F −, Cl −, Br −, I −, N 3 −, NCS −, OCN −, NO 2 − and C 2H 3O 2 − have been synthesized and characterized. I.R. and electronic absorption spectra have been measured and tentative band assignments made. The room temperature magnetic susceptibility measurements on the complexes in chloroform and dimethysulfoxide solution yield magnetic moments of ∼4·9 B.M., i.e. the expected spin only value for high spin Mn(III). Conversely, magnetic moments of the solid complexes range from 4·2 to 5·0 B.M. depending on the anion. It is suggested that the lowering of the moment is due to the formation of dimers with antiferromagnetic interaction, in the solid.