Synthesis, structure, and magnetism of a series of self-assembled polynuclear Mn(II), Co(II), and Cu(II) cluster complexes

The single-crystal structures and magnetic properties of a series of self-a ssembled cluster complexes of Mn(II), Co(II), Co(II)/Co(III), and Cu(II), w ith a group of alkoxy-diazine ligands, which have square and rectangular pr imary architectures, are reported. In one novel case a secondary coordinati on sphere of metal ions can be built up on a square core, due to the presen ce of vacant extra-core coordination sites. [Mn-4 (poapz-H)(4)(H2O)(4)](NO3 )(4).H2O (1); monoclinic, C2/c, a = 21.7120(4) Angstrom, b = 17.421(4) Angs trom, c = 17.273(4) Angstrom, beta = 109.34(3). [Co-4(poap-H)(2)(poap-2H)(2 )](NO3)(4). 7H(2)O (3); triclinic, P (1) over bar, a = 9.6855(6) Angstrom, b = 12.9462(7) Angstrom, c = 13.7383(8) Angstrom, alpha = 106.5730(10), bet a = 99.0400(10) Angstrom, gamma = 95.737(10)degrees. [Co-4(poapz-H)(4) (H2O )(4)](NO3)(4). 2H(2)O (4); monoclinic, C2/c, a = 21.160(2) Angstrom, 17.808 (2) Angstrom, c = 17.000(2) Angstrom, beta = 106.904(9)degrees. [Co-4(pzoap z-H)(4) (H2O)(4)](ClO4)(4). 3H(2)O (5); monoclinic, P2(1)/a, a = 23.24(1) A ngstrom, b = 13.681(3) Angstrom, c = 23.37(2) Angstrom, beta = 118.17(4)deg rees. [Cu-4(poap-H)(4)] (ClO4)(4). CH3CN .4.75H(2)O (6); triclinic, P (1) o ver bar, a = 13.966(1) Angstrom, b = 14.195(1) Angstrom, c = 19.452(2) Angs trom, alpha = 83.435(2)degrees, beta = 80.727(1), gamma = 63.023(1)degrees. [Cu-5(3poap-H)(3)(3poap-3H)] (ClO4)(4).7.5H(2)O (7); triclinic, P (1) over bar, a = 11.8316(12) Angstrom, b = 14.7017(16) Angstrom, c = 21.1527(23) A ngstrom, alpha = 92.401(2)degrees, beta = 104.690(2)degrees, gamma = 104.58 6(2)degrees. Magnetic properties are interpreted in relation to the structu res. The Mn(II) complexes (1, 2) and the Co(II) complexes (4, 5) exhibit in tramolecular antiferromagnetic coupling associated with large M-O-M angles, the Cu(II)(4) complex 6 exhibits intramolecular ferromagnetic coupling due to magnetic orbital orthogonality, while the Cu(II)(5) complex 7 is best d escribed as a combination of a ferromagnetic trinuclear subunit and an anti ferromagnetic dinuclear subunit. (C) 2001 Academic Press.