Reaction of di-(2-pyridyl)ketone (dpk) with [M3(CO)12], M =Ru or Os in dioxan under reduced pressure gave the tricarbonyl derivative [Ru(CO)3(dpk)] (1) and [Os(CO)3(dpk)] (2). When these reactions were carried out in benzene/ethanol 1:1 (v:v) under reflux and reduced pressure gave the binuclear ruthenium complex [Ru2(CO)4(m-CO)(h3-dpkO,Oeth)2] (3),where h3-dpkO,Oeth is N,O,N-ethoxybis(2-pyridyl)-methanolato and the mononuclear [Os(CO)3(h3-dpkO,Oeth) (4). All complexes were characterized by elemental analysis, infrared, mass and 1H NMR spectroscopy. The spectroscopic measurements indicated that in dioxane as solvent the dpk act as bidentate ligand while in benzene/ethanol solution the dpk act as tridentate ligand. The magnetic measurements revealed that the complexes (3) and (4) are paramagnetic with change in the formal oxidation state of the ruthenium and osmium atoms from zero to +1 via oxidative addition of the OH group to ruthenium or osmium with a proton displacement to give a low-spin d7 electronic configuration The UV–Vis studies of the complexes showed blue shift compared to the ligand confirming complex formation.