Synthesis, characterization, crystal structures and magnetic properties of dissymmetrical double schiff base heterotrinuclear complexes: [CuL(H2O)CoCuL]·H2O·CH3OH and [(CuL)2Ni]·2H2O

A dissymmetrical double Schiff base Cu(II) mononuclear complex: CuHL ( 1 ) (where H 3 L is N -3-carboxylsalicylidene- N ′ -salicylaldehyde-1,2-diaminoethane) and two trinuclear complexes: [CuL(H 2 O)CoCuL] · H 2 O · CH 3 OH ( 2 ) and [(CuL) 2 Ni] · 2H 2 O ( 3 ) have been synthesized and characterized by means of elemental analyses, IR and electronic spectra. The crystal structures of two heterotrinucler complexes were determined by X-ray analysis. Each dissymmetrical cell unit of the complex 2 contains two heterotrinucler neutral molecules. In each neutral molecule, the central Co 2+ ion is located at the site of O 6 with a distorted octahedral geometry and one terminal Cu 2+ ion at the four-coordination site of N 2 O 2 , but the other one at the square-pyramidal environment of N 2 O 3 . Each dissymmetrical unit of the complex 3 contains a heterotrinucler neutral molecule, whose structure is similar to that of 2 except two terminal Cu 2+ ions both at the inner site of N 2 O 2 . The magnetic properties of two heterotrinucler complexes have been determined in the temperature range of 5–300 K, which indicate that the interaction between the central Co 2+ ion or Ni 2+ ion and the outer Cu 2+ ions is antiferromagnetic. The exchange integrals are equal to −26.2 cm −1 for 2 and −50.6 cm −1 for 3 .