LAUSR

Abstract The recent developments in the direction of metal chelation assisted diverse mode of functionalization of β-diketiminate (nacnac) led to the present deliberation of C(sp2)–H bond oxygenation of Ru-coordinated nacnac through small molecule (O2) activation. In this context the present article dealt with the synthesis and structural/spectroscopic/electrochemical characterization of a set of newer complexes: [RuII(pap)2(nacnacPh,Ph)]ClO4 (1), [RuII(bpy)2(nacnacPh,Ph)]ClO4 (2), [RuII(bpy)2(L1Ph,Ph)](ClO4)2 (3), [RuIII(acac)2(nacnacPh,Cyx)] (4) and [RuII(acac)2(L1Ph,Cyx)] (5) (pap = strongly π-acidic 2-phenylazopyridine, bpy = moderately π-acidic 2,2′-bipyridine, acac = σ-donating acetylacetonate, nacnacPh,Ph = N-phenyl substituted symmetric nacnac, nacnacPh,Cyx = N-pheyl/N-cyclohexyl substituted unsymmetric nacnac and L1 = α-ketodiimine). Though nacnac moiety in {RuII(pap)2} derived 1 remained unperturbed, the same in {RuII(bpy)2} and {RuIII(acac)2} derived 2 and 4 underwent oxygenation to α-ketodiimine moiety (Cβ − H → C O) in 3 and 5, respectively, at a varying rate. The observed ancillary ligand (pap, bpy, acac) and spin state (S = 0 in 1 or 2 and S = 1/2 in 4) dependent varying rate of oxygenation of nacnac in the complexes was addressed via experimental investigations in combination with DFT calculations. Moreover, the redox noninnocence of β-diketiminate (nacnac) and α-ketodimine (L1) in the aforesaid complexes was highlighted.