The structures and magnetism of trinuclear Ni(II), Co(II) and Mn(II) complexes derived from unsymmetrical compartmental ligands

Trinuclear Ni(II), Co(II) and Mn(II) complexes have been prepared from the asymmetric compartmental proligands 2-alkyliminomethyl-4-methyl-6-{[methyl-(2-pyridin-2-yl-ethyl)-amino]-methyl}-phenol(alkyl=ethyl, n-propyl and n-butyl) and 2-[(2-methoxy-ethylimino)-methyl]-4-methyl-6-{[methyl-(2-pyridin-2-yl-ethyl)-amino]-methyl}-phenol, which provide adjacent tridentate N2O and bidentate NO donor sets. The crystal structures of [Ni3(L6)2(OAc)2(NCS)2] · CH3OH · H2O, [Co3(L4)2(OAc)2(NCS)2], and [Mn3(L7)2(OAc)2(NCS)2] · CH3OH · H2O were determined and show that the metals provide an isosceles triangle with M1–M2=M1–M3 ≈ 3.2 Å and M2-M3 ≈ 5.0 Å. The cryomagnetic properties of the complexes have been studied and indicate a weak antiferromagnetic interaction between the adjacent, M1M2 and M1M3 ions with little magnetic interaction between the terminal M2M3 ions.