The employment of pyridine-2-carbaldehyde oxime (paoH) in zinc(II) benzoate chemistry, in the absence or presence of azide ions, is described. The syntheses, crystal structures and spectroscopic characterization are reported for the complexes [Zn(O2CPh)2(paoH)2] (1), [Zn12(OH)4(O2CPh)16(pao)4] (2) and [Zn4(OH)2(pao)4(N3)2] (3). The ZnII centre in octahedral 1 is coordinated by two monodentate PhCO2− groups and two N,N′-chelating paoH ligands. The metallic skeleton of 2 describes a tetrahedron encapsulated in a distorted cube. The {Zn12(μ-OH)4(μ3-ΟR)4}16+ core of the cluster can be conveniently described as consisting of a central {Zn4(μ3-ΟR)4}4+ cubane subunit (RO− = pao−) linked to four {Zn2(μ-OH)}3+ subunits via the OH− group of each of the latter, which becomes μ3. The molecule of 3 has an inverse 12-metallacrown-4 topology. Two triply bridging hydroxido groups are accommodated into the metallacrown ring. Each pao− ligand adopts the η1 : η1 : η1 : μ coordination mode, chelating one ZnII atom and bridging a ZnII2 pair. Complexes 1 and 2 display photoluminescence with maxima at ∼355 nm and ∼375 nm, upon maximum excitation at 314 nm; the origin of the photoluminescence is discussed.
