Highly Emissive Platinum(II) Complexes Bearing Bulky Phenyltriazolate Ligands: Synthesis, Structure, and Photophysics

Abstract

Dinuclear and mononuclear cycloplatinated(II) complexes (1−3 and 4−6) with formulas [Pt(bt)(μ-L)] 2 and Pt(bt)(L) [bt = 2-phenylbenzothiazole, μ-L = deprotonated diphenyl(2-(5-phenyl-4H-1,2,4-triazol-3yl)phenyl)phosphine oxide derivatives for L1−L3, and L = deprotonated 3-(2-(diphenylphosphino)phenyl)-5-phenyl-4H-1,2,4-triazole derivatives for L4−L6]have been successfully synthesized and systematically characterized. Singlecrystal X-ray analysis demonstrates that these complexes exhibit distorted square-planar geometries around Pt(II) centers. There are no apparent intermolecular π−π and Pt−Pt interactions owing to the presence of bulky ligands. Therefore, these complexes achieve excellent monomeric emission in solution, PMMA films, and the solid state with a photoluminescence quantum yield (Φ) up to 67.3% in the solid state. The photophysical behaviors associated with theoretical investigations reveal that the emissions of these complexes possess primarily a 3 LC feature together with some 3 MLCT character.

Luminescent Anionic Cyclometalated Organoplatinum (II) Complexes with Terminal and Bridging Cyanide Ligand: Structural and Photophysical Properties

“…The emissions in glassy solutions do not reveal any systematic dependence on the solvent (Figure S19 for 6 and 9 ). These emissions are typical of metal-perturbed C^N 3 (π → π*) excited states and, accordingly, the energy peak maximum is subtly red-shifted on going from dfppy to ppy and to bzq derivatives (MeOH, 77 K: 456 6 ; 474 5 ; 477 nm 4 and 458 3 ; 478 2 ; 479 nm 1 ), in line with the more delocalized bzq target ligand and the presence of electron-acceptor fluorine atoms in the phenyl ring. ,,,, According to DFT calculations, , these emissions are ascribed to 3 LC with 3 MLCT character. For the bzq complexes, the lifetimes are extremely longer than those measured for the ppy and dfppy (MeOH 77 K, 323.2 1 ; 289.9 μs 4 ).…”

“…These emissions are typical of metal-perturbed C^N 3 (π → π*) excited states and, accordingly, the energy peak maximum is subtly red-shifted on going from dfppy to ppy and to bzq derivatives (MeOH, 77 K: 456 6; 474 5; 477 nm 4 and 458 3; 478 2; 479 nm 1), in line with the more delocalized bzq target ligand and the presence of electron-acceptor fluorine atoms in the phenyl ring. 31,43,57,76,77 According to DFT calculations, 78,79 these emissions are ascribed to 3 LC with 3 MLCT character.…”

Incorporation of a Fluorine Atom in a Bridging Ligand of Half-Lantern PtII2 Complexes Provides up to 10-Fold Enhancement of Electroluminescence Brightness

“…For this study, we addressed the half-lantern Pt II 2 complexes [Pt­(pbt)­(μ-S ∧ N)] 2 ( Pt1 - 5 , Scheme ), where pbtH is 2-phenylbenzothiazole and S ∧ N is benzo­[ d ]­thiazole-2-thiolate ligand, featuring either hydrogen or a halogen atom (X = F, Cl, Br, and I) in the 6th position. The former was chosen as the cyclometalated ligand because, as previously reported, − its platinum­(II) complexes are potent phosphorescent species exhibiting high luminescent efficiency; pbt-based complexes have been previously applied as emissive materials in OLEDs. , The platinum complexes Pt1 - 5 were prepared via the two-step synthetic procedure (Scheme ).…”

N,C,N-Pincers in Platinum Bimetallic Complexes: Influence of the Pincer and Bridging Ligands on the Metal–Metal Bond and the Photophysical Properties

“…Yield: 254 mg (95% (d with 195 Pt satellites, J H−H = 8.4, J H−Pt = 30.0, 2H py NCN), 1H az +2H py NCN),1H Ph),7.13 (d,2H Ph),2H py NCN + 1H az). 13 7). Indolo[2,indole (66 mg, 0.318 mmol) was added to a suspension of 3 (100 mg, 0.212 mmol) in acetone (5 mL), and the resulting mixture was stirred for 6 h at room temperature getting a reddish orange suspension.…”