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-[(2methoxy-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 [Ni-3(L-6)(2)(OAc)(2)(NCS)(2)] . CH3OH . H2O, [Co-3(L-4)(2)(OAc)(2)(NCS)(2)], and [Mn-3(L-7)(2)(OAc)(2)(NCS)(2)] . CH3OH . H2O were determined and show that the metals provide an isosceles triangle with M-1-M-2=M-1-M-3 approximate to 3.2 Angstrom and M-2-M-3 approximate to 5.0 Angstrom. The cryomagnetic properties of the complexes have been studied and indicate a weak antiferromagnetic interaction between the adjacent, (MM2)-M-1 and (MM3)-M-1 ions with little magnetic interaction between the terminal (MM3)-M-2 ions. (C) 2004 Elsevier B.V. All rights reserved.