Synthesis and characterization of luminescent osmium(ii) carbonyl complexes based on chelating dibenzoylmethanate and halide ligandsElectronic supplementary information (ESI) available: experimental details and the spectral data of all isolated Os complexes. See http://www.rsc.org/suppdata/cc/b3/b308340c/

Abstract

Octahedral Os(II) complexes 1-5 with formula [Os(CO)3X(dbm)] are prepared through utilization of both solid-state pyrolysis and ligand exchange reactions. These complexes exhibit prominent 3pi-pi* phosphorescence with unusually long lifetimes (29-64 micros) and high quantum yields (0.08-0.13).

Strategic Design and Synthesis of Osmium(II) Complexes Bearing a Single Pyridyl Azolate π-Chromophore: Achieving High-Efficiency Blue Phosphorescence by Localized Excitation

“…As depicted in Figure , the structure consists of a central Os(II) atom chelated by an fppz ligand, together with the attachment of one terminal tfa anion and three CO ligands. Its coordination arrangement is akin to that of the diketonate complexes [Os(CO) 3 (tfa)(hfac)], hfac = hexafluoroacetylacetonate, and the 8-quinolinolate derivative [Os(CO) 3 (tfa)(O ∧ N)], O ∧ N = quinolinolate; the latter even shows the room-temperature dual fluorescence and phosphorescence arising from inefficient singlet−triplet intersystem crossing …”

Probing Triplet State Properties of Organic Chromophores via Design and Synthesis of Os(II)-Diketonate Complexes: The Triplet State Intramolecular Charge Transfer

“…The addition of back π-bond donating carbonyl ligands should further increase the d−d energy gap, so that the organic chromophore of interest, i.e., β-diketonate, is expected to lie in the lower-lying excited states. The β-diketonate ligand with both donor and acceptor substituents was synthesized through a Claisen condensation reaction, in which treatment of 2-acetonaphthone and 4-dimethylaminobenzoic acid ethyl ester in the presence of a strong base NaH gives the desired diketone, 2-naphthyl-7-dimethylanilino-1,3-propanedione (NDP)H. To prepare the Os(II)−metal complexes, we selected the literature method designed for the related dibenzoylmethanate complex [Os(CO) 3 (tfa)(dbm)], tfa = CF 3 CO 2 - and (dbm)H = dibenzoylmethane . In this approach, heating the finely pulverized solid-state mixture of (NDP)H and osmium dimer [Os 2 (CO) 6 (tfa) 2 ] afforded [Os(CO) 3 (tfa)(NDP)] (1a) .…”

Synthesis, Characterization, and Photophysical Properties of Os(II) Diimine Complexes [Os(N∧N)(CO)2I2] (N∧N = Bipyridine, Phenanthroline, and Pyridyl Benzoxazole)

“…Two iodides are located at the mutual trans position and lean slightly toward the dpphen ligand with ∠I(1)−Os−I(2) = 173.93(3)°; this may be the result of the crystal packing effect. The Os−I distances (Os−I(1) = 2.7002(7) Å and Os−I(2) = 2.6781(7) Å) are shorter than those of the structurally characterized complex [Os(dbm)(CO) 3 I] (2.721(1) Å), in which the unique iodine ligand is trans to a much stronger π-accepting carbonyl ligand. Finally, the overall ligand arrangement of 3 is related to that of the Ru analogues, [Ru(bpy)(CO) 2 Cl 2 ] and [Ru(dmbpy)(CO) 2 Cl 2 ], showing thermodynamically more stable trans (halide, halide) and cis (CO, CO) configurations.…”