Luminescence of iridium(II) chelates with 2,2'-bipyridine and with 1,10-phenanthroline

Luminescence Spectra of Transition Metal Complexes*

“…2). Our experi- luminescence are dd in characteristics, whereas Wunschel and Ohnesorge [20] find for [ Ir(lll)phen,]+++ that the lowest absorption and luminescence are d a, in characteristics.…”

Electronic spectra of ruthenium and osmium tetroxides

“…When two i-MO's are listed, the order of listing is the serial order of appearance in columns 2-4. 6 The letters A and F in parentheses denote allowed and forbidden electric dipole transitions, respectively. c The symbols in parentheses represent the terminal Rydberg AO, R.…”

Luminescent Iridium(III) Complexes Supported by N-Heterocyclic Carbene-based C^C^C-Pincer Ligands and Aromatic Diimines

“…1–2 exhibit intense, high-energy absorptions at λ ≤ 340 nm (ε ≥ 10 4 dm 3 mol −1 cm −1 ), and moderately intense bands at λ > 340 nm (ε ≈ 10 3 dm 3 mol −1 cm −1 ) with tailing up to 530 nm. In the literature, Ir(III) complexes bearing aromatic diimine ligands such as [Ir(bpy) 3 ] 3+ and [Ir(phen) 3 ] 3+ feature highly intense absorptions at λ ≤ 320 nm (ε ≥ 10 4 dm 3 mol −1 cm −1 ), and these are ascribed to π → π*(N^N) intraligand (IL) transitions 37 38 39 . In addition, [Ir(C 1 ^C^C 1 ) 2 ] + exhibits intense absorptions at λ ≤ 330 nm (ε ≥ 10 4 dm 3 mol −1 cm −1 ), which are expected to be a mixture of d π (Ir III ) → π*(C^C^C) metal-to-ligand charge transfer (MLCT) and π → π*(C^C^C) IL transition.…”

“…On the other hand, the electronic transitions at λ = 340–530 nm (ε ≤ 10 3 dm 3 mol −1 cm −1 ) for 1 – 2 should contain some d π (Ir III ) → π*(N^N) MLCT character, reasons are as follows: (1) [Ir(bpy) 3 ] 3+ , [Ir(phen) 3 ] 3+ , and [Ir(ppy) 2 (bpy)] + (ppy = 2-phenylpyridine) feature d π (Ir III ) → π*(N^N) MLCT transitions in similar energy region (λ max = 370–520 nm, ε ≤ 10 3 dm 3 mol −1 cm −1 ); 38 39 40 41 42 43 (2) a red-shift in absorption energy is observed when N^N is changed from Me 2 bpy to bpy, and from phen to dpq; (3) 1 – 2 display solvatochromic effect in the spectral region concerned. For example, the λ max for 1a within this spectral region is 374 nm in CH 3 CN, and is 384 nm in CH 2 Cl 2 ; (4) there are no corresponding absorption bands for [Ir(C 1 ^C^C 1 ) 2 ] + .…”