Self assembled polynuclear [3 x 3] grids - structural and magnetic properties of Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) complexes with Mn-9(mu(2)-O)(12) cores

A series of polynuclear [3 x 3] square grid complexes of Mn(II), Fe(III), C o(II), NI(II), and Cu(II) is reported from the high yield self assembly rea ctions of the linear tritopic ligands H(2)L3 and H(2)L4 and appropriate met al salts. Structural data reveal a complementary matching of the ligand coo rdination pockets and the coordination requirements of the metal ions in th e [3 x 3] square alkoxide bridged grids found in [Mn-9(L3)(6)](ClO4)(6). 18 H(2)O, [Mn-9(L4)(6)](NO3)(6). 12H(2)O and [Cu-9(HL3)(6)](NO3)(12). 9H(2)O. Similar structural types are implicated for analogous Ni(II), Co(II), and F e(III) complexes. The structural and magnetic properties are discussed. The Cu-9 grid system exhibits both intramolecular ferromagnetic and antiferrom agnetic coupling, and has an S = 7/2 ground state. A similar situation appe ars to exist for the analogous Fe(III), complex, with a spin ground state a pproaching S = 29/2. The Mn(II)(9), Ni(II)(9) and Co(II)(9) complexes exhib it intramolecular antiferromagnetic coupling. (C) 2001 Elsevier Science Ltd . All rights reserved.