Dinuclear CoIII/PrIII and CoIII/Nd III complexes derived from a hexadentate Schiff base: Synthesis, structure and magnetic properties

Abstract

Two heterodimetallic complexes of formulae [LCo(AcO)2Pr(NO 3)2] and [LCo(AcO)2Nd(NO3)2] (H 2L=N,N'-bis(3-methoxysalicylidene) propane-1,2-diamine) have been synthesised and structurally characterised. The cobalt(III) ion shows a slightly distorted octahedral geometry in which the equatorial plane is formed by the N2O2 set of the Salen-type Schiff base, and the axial positions are occupied by two oxygen atoms from both acetate groups. The praseodymium(III) and neodymium (III) ions are decacoordinated. In addition to the four oxygen atoms of the Schiff base, the rare earth ions coordinate two bidentate nitrate groups and two oxygen atoms of the acetate groups. The metal ions are bridged by both the phenolate oxygens and the acetate groups. The χMT values observed for the complexes are lower than the free-ion approximation of PrIII and NdIII ions, although the cobalt(III) is diamagnetic.