The use of di-2-pyridyl ketone, (py) 2CO, in zinc(II) nitrate chemistry has yielded a dinuclear complex and a cationic tetranuclear cluster. The 1:1 Zn(NO 3) 2·4H 2O/(py) 2CO reaction system in EtOH gives [Zn 2(NO 3) 2{(py) 2C(OEt)O} 2]·0.5H 2O ( 1·0.5H 2O), whereas the same reaction system in MeCN yields [Zn 4(NO 3) 3{(py) 2C(OH)O} 4(H 2O)](NO 3) ( 2). The monoanionic derivatives of the hemiacetal and the gem-diol forms of di-2-pyridyl ketone have been derived from the Zn(II)-mediated addition of solvent (EtOH, H 2O involved in MeCN) on the carbonyl group of (py) 2CO. Each (py) 2C(OEt)O − ion functions as an η 1:η 2:η 1:μ 2 ligand in 1·0.5H 2O chelating the two Zn II atoms through the 2-pyridyl nitrogen atoms and the common bridging, deprotonated oxygen atom; one asymmetric chelating nitrate completes six coordination at each metal center. The tetranuclear cluster cation of 2 has a cubane topology with the Zn II ions and the deprotonated oxygen atoms from the four η 1:η 3:η 1:μ 3 (py) 2C(OH)O − ligands occupying alternate vertices. Three monodentate nitrates and one aqua ligand complete the sixth coordination site at the metal ions. The two complexes have been characterized by IR and far-IR spectroscopies. Characteristic bands are discussed in terms of the known structures and the coordination modes of the nitrato ligands. Upon excitation at 371 nm, complex 2 displays blue photoluminescence in the solid state at room temperature with two emission maxima at 430 and 455 nm.