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The synthesis of the new polynucleating ligand 1,3-bis-3-oxo-3-2-hydroxyphenyl-propionyl-benzene H4L is reported along with the preparation, structure and properties of its dinuclear complexes Cu2H2L2py21, Ni2H2L2py42, Mn2H2L2dmf43, Co2H2L2dmf44 and Co2H2L2MeOH45, respectively. In complexes 1to 5, the polydentate ligand is in its bis-deprotonated form, chelating the metals through its β-diketonate moieties. Magnetic measurements show that the metals within these molecules are maintained almost mutually independent.

Nickel and cobalt heterocubanes have been synthesised from dinuclear complexes. The use of 8-hydroxyquinaldine leads to a rhombohedral distortion in two faces of the cubes. Both cubes were studied by paramagnetic NMR, which shows that they are stable in solution. Magnetic measurements show that the coupling within both molecules is overall antiferromagnetic. The magnetic data for the nickel cube has been modelled, and shows that the coupling consists of two ferromagnetically coupled pairs which are antiferromagnetically coupled to give a diamagnetic ground state.

The structure of a discrete hexacopper(ii) barrel cluster and that of a coordination polymer formed by a related hexanuclear repeating unit have been determined. The CuII metals of the hexanuclear units are held together by eight chelating L-prolinato type ligands, which in turn provide the eight oxygen donors trapping a sodium ion in the center. The structure of the [Cu₆Na] unit in the discrete system and in the infinite cluster-chain are essentially the same and both display intra-unit ferromagnetic superexchange. A preliminary magnetic study shows that, for both compounds, the copper centers within the [Cu₆] unit are ferromagnetically coupled, yielding an S = 3 spin ground state.

The reaction of the complex [Ni₂(H₂O)(piv)₄(Hpiv)₄] (1) (Hpiv = pivalic acid) with Hppo (3-phenylpyrazolin-5-one) in the presence of a base of an alkaline-earth metal (MII = MgII, SrII or BaII) has led to three different NiII clusters whose structures are controlled by the nature of MII. The formulae of the new heteronuclear cages are [Ni₆Mg₂(OH)₂(ppo)₄(piv)₁₀(Hppo)₄(MeOH)₂] (2), [Ni₈Sr(OH)₂(ppo)₆(piv)₁₀(Hppo)₅(Hpiv)₂(MeCN)] (3) and [Ni₈Ba(OH)₂(ppo)₆(piv)₁₀(Hppo)_5.3(Hpiv)_0.7(MeCN)₂] (4). Magnetic measurements indicate that the spin ground state of 2 consists of two independent S = 3 units, while the presence of two non-interacting S = 2 fragments in the molecule is postulated for compounds 3 and 4.

The reaction of the complex Ni2H2Opiv4Hpiv41 Hpiv pivalic acid with Hppo 3-phenylpyrazolin-5-one in the presence of a base of an alkaline-earth metal MII MgII, SrIIor BaII has led to three different NiIIclusters whose structures are controlled by the nature of MII. The formulae of the new heteronuclear cages are Ni6Mg2OH2ppo4piv10Hppo4MeOH22, Ni8SrOH2ppo6piv10Hppo5Hpiv2MeCN 3 and Ni8BaOH2ppo6piv10Hppo5.3Hpiv0.7MeCN24. Magnetic measurements indicate that the spin ground state of 2consists of two independent S 3 units, while the presence of two non-interacting S 2 fragments in the molecule is postulated for compounds 3and 4.

The structure of a discrete hexacopperii barrel cluster and that of a coordination polymer formed by a related hexanuclear repeating unit have been determined. The CuIImetals of the hexanuclear units are held together by eight chelating L-prolinato type ligands, which in turn provide the eight oxygen donors trapping a sodium ion in the center. The structure of the Cu6Na unit in the discrete system and in the infinite cluster-chain are essentially the same and both display intra-unit ferromagnetic superexchange. A preliminary magnetic study shows that, for both compounds, the copper centers within the Cu6 unit are ferromagnetically coupled, yielding an S 3 spin ground state.