A simple design strategy for a new class of stable, vacuum-sublimable, and strongly emissive sky-blue neutral phosphorescent Re(I) phenanthroline complexes {Re(R 2 phen)(CO) 3 [CNB(C 6 F 5 ) 3 ]} is reported. These complexes show intense bluish green emission in CH 2 Cl 2 solution with the highest emission quantum yield and bluest emission ever reported for the neutral Re(I) diimine complexes. In the solid state, they display sky-blue emission. The electroluminescent properties of devices containing these complexes have also been investigated.

A new series of cyclometalated iridium(III) complexes with isocyanoborate ligands [Ir(R2ppy)2(L)(CNBR'3)] (R = H or F; L = CNC6H4Cl-4 or PPh3; R' = Ph, C6F5 or C6H4Cl-4), [Ir(biqb)(ppy)(CNBR''3)] (R'' = C6F5 or C6H4Cl-4) and {Ir(ppy)2(CN)n[CNB(C6F5)3]2-n}(-) (n = 0 or 1) have been synthesized and characterized. Three of these complexes have also been structurally characterized by X-ray crystallography. The photophysical and electrochemical properties of these complexes have been investigated. The effects of isocyanoborate ligands on the luminescence properties of these iridium(III) complexes are also described.

A new series of neutral isocyanoborato rhenium(I) diimine complexes [Re(CO)3 (N^N)(CNBR3 )], where N^N=bpy, 4,4'-Me2 bpy, phen, 4,7-Me2 phen, 2,9-Me2 phen, 3,4,7,8-Me4 phen; R=C6 F5 , C6 H5 , Cl, 4-ClC6 H4 , 3,5-(CF3 )2 C6 H3 , with various isocyanoborate and diimine ligands of diverse electronic and steric nature have been synthesized and characterized. The X-ray crystal structures of six complexes have also been determined. These complexes displayed intense bluish green to yellow phosphorescence at room temperature in dichloromethane solution. The photophysical and electrochemical properties of these complexes had been investigated. To elucidate the electronic structures and transitions of these complexes, DFT and TD-DFT calculations have been performed, which revealed that the lowest-energy electronic transition associated with these complexes originates from a mixture of MLCT [dπ(Re)→π*(N^N)] and LLCT [π(CNBR3 )→π*(N^N)] transitions.

A new class of neutral bis(isocyanoborato) bis(bipyridyl) Os(II) complexes with the general formula of [Os(N−N) 2 (CNBR 3 ) 2 ] (N−N = bpy, 4,4′-Me 2 bpy; R = C 6 F 5 , C 6 H 5 ) were prepared with simple synthetic methodologies. One of these complexes was structurally characterized by X-ray crystallography. Unlike most of the neutral bis(bipyridyl) Os(II) complexes, which are very weakly emissive or nonemissive, these isocyanoborato complexes displayed intense orange to red phosphorescence with a luminescent quantum yield up to 0.09 in CH 2 Cl 2 solution at room temperature. The photophysical and electrochemical properties of these complexes were also investigated. Detailed photophysical study showed that these complexes exhibited significantly enhanced emission properties over other reported neutral bis(bipyridyl) Os(II) complexes. In addition, it also revealed that the photophysics, electrochemistry, and excited state properties can be fine-tuned or modified through the functionalization of isocyanoborate ligands.

A series of luminescent isocyanorhenium(I) complexes with chelating acyclic diaminocarbene ligands (N^C) has been synthesized and characterized. Two of these carbene complexes have also been structurally characterized by X-ray crystallography. These complexes show blue-to-red phosphorescence, with the emission maxima not only considerably varied with a change in the number of ancillary isocyanide ligands but also extremely sensitive to the electronic and steric nature of the substituents on the acyclic diaminocarbene ligand. A detailed study with the support of density functional theory calculations revealed that the lowest-energy absorption and phosphorescence of these complexes in a degassed CH2Cl2 solution are derived from the predominantly metal-to-ligand charge-transfer [dπ(Re) → π*(N^C)] excited state. The unprecedented anion-binding and CO2-capturing properties of the acyclic diaminocarbene have also been described.