Two binuclear cyanide-bridged Cr(III)-Mn(III) complexes based-on [Cr(2,2’-bipy)(CN)4]- building block: synthesis, crystal structures and magnetic properties

Abstract

Tetracyanide building block [Cr(2,2'-bipy)(CN) 4 ] -and two bicompartimental Schiff-base based manganese(III) compounds have been employed to assemble cyanide-bridged heterometallic complexes, resulting in two cyanide-bridged. Single-crystal X-ray diffraction analysis shows their similar cyanide-bridged binuclear structures, in which the cyanide precursor acts as monodentate ligand connecting the manganese(III) ion. The binuclear complexes are self-complementary through coordinated aqua ligand and the free O 4 compartment from the neighboring complex, giving H-bond linking dimer structure. Investigations on magnetic properties reveal the antiferromagnetic coupling between the cyanide-bridged Cr(III) and Mn(III) ions. By using a Fortran program through numerical matrix diagonalization techniques, a best-fit to the magnetic susceptibilities of these two complexes leads to the magnetic coupling constants J ≡ -5.95 cm , j ≡ -0.57 cm -1 (2), respectively.