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-assembled cluster complexes of Mn(II), Co(II), Co (II)/Co(III), and Cu(II), with a group of alkoxy-diazine ligands, which have square and rectangular primary architectures, are reported. In one novel case a secondary coordination sphere of metal ions can be built up on a square core, due to the presence of vacant extra-core coordination sites. [Mn4(poapz-H)4(H2O)4](NO3)4·H2O (1); monoclinic, C2/c, a=21.7120 (4) ?, b=17.421(4) ?, c=17.273(4) ?, =109.34(3)°. [Co4(poap-H)2(poap-2H)2](NO3)4·7H2O (3); triclinic, P , a= 9.6855(6) ?, b=12.9462(7) ?, c=13.7383(8) ?, =106.5730(10), =99.0400(10) ?, =95.737(10)°. [Co4(poapz-H)4(H2O) 4](NO3)4·2H2O (4); monoclinic, C2/c, a=21.160(2) ?, 17.808(2) ?, c=17.000(2) ?, =106.904(9)°. [Co4(pzoapz-H)4 (H2O)4](ClO4)4·3H2O (5); monoclinic, P21/a, a=23.24(1) ?, b=13.681(3) ?, c=23.37(2) ?, =118.17(4)°. [Cu4(poap-H)4] (ClO4)4·CH3CN·4.75H2O (6); triclinic, P , a=13.966(1) ?, b=14.195(1) ?, c=19.452(2) ?, =83.435(2)°, =80.727(1)°, =63.023(1)°. [Cu5(3poap-H)3(3poap-3H)] (ClO4)4·7.5H2O (7); triclinic, P , a=11.8316(12) ?, b=14.7017(16) ?, c= 21.1527(23) ?, =92.401(2)°, =104.690(2)°, =104.56(2)°. Magnetic properties are interpreted in relation to the structures. The Mn(II) complexes (1, 2) and the Co(II) complexes (4, 5) exhibit intramolecular 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 described as a combination of a ferromagnetic trinuclear subunit and an antiferromagnetic dinuclear subunit.