93369-32-5Relevant academic research and scientific papers
PHOSPHORESCENT IRIDIUM COMPLEXES
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Paragraph 0061; 0062; 0072; 0073, (2016/10/17)
Metal complexes of formula I and IA and polymers derived from the complexes are useful in optoelectronic devices wherein M is Ir, Co or Rh; is a cyclometallated ligand; R1 is hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, or substi
Iridium-mediated N-H and methyl C-H bond activations in N-(2′6′- dimethylphenyl)pyrrole-2-aldimine. Synthesis, characterization and catalytic applications
Paul, Piyali,Richmond, Michael G.,Bhattacharya, Samaresh
, p. 760 - 768 (2014/03/21)
Reaction of N-(2′,6′-dimethylphenyl)pyrrole-2-aldimine (L-Me2) with I r(PPh3)3Cl in refluxing toluene affords two organometallic complexes (1 and 2), where the imine-ligand (L-Me2) is coordinated to the metal center, via N-H and methyl C-H activations, as a di-anionic tridentate NNC-donor, along with two triphenylphosphines. In 1 the sixth coordination site is occupied by a hydride, while in 2 by a chloride. In both cases the hydride or chloride is trans to the coordinated imine-nitrogen, and the two triphenylphosphines are mutually trans. Similar reaction of N-(2′-methylphenyl)pyrrole-2-aldimine (L-Me) with Ir(PPh3)3Cl affords 3, where the imine-ligand is coordinated to the metal center as a mono-anionic bidentate NN-donor, along with two triphenylphosphines, a hydride and a chloride. Structures of 1, 2 and 3 have been determined by X-ray crystallography. DFT analyses have been carried out to understand the formation of the complexes. All the complexes show characteristic 1H NMR signals and, intense transitions in the visible and ultraviolet regions. Cyclic voltammetry on all three complexes shows two irreversible oxidations within 0.89-1.34 V vs. SCE and a reduction within -1.31 to -1.40 V vs. SCE. Complexes 1, 2 and 3 have been found to efficiently catalyze the Oppenauer oxidation of alcohols.
Tunable fluorophores based on 2-(N-Arylimino)pyrrolyl chelates of diphenylboron: Synthesis, structure, photophysical characterization, and application in OLEDs
Suresh,Lopes, Patricia S.,Ferreira, Bruno,Figueira, Claudia A.,Gomes, Clara S. B.,Gomes, Pedro T.,Di Paolo, Roberto E.,MacAnita, Antonio L.,Duarte, M. Teresa,Charas, Ana,Morgado, Jorge,Calhorda, Maria Jose
, p. 4126 - 4140 (2014/04/17)
Reactions of 2-(N-arylimino)pyrroles (HNC4H3C(H)=N- Ar) with triphenylboron (BPh3) in boiling toluene afford the respective highly emissive N,N-boron chelate complexes, [BPh2{κ 2N,N-NC4H3C(H)=N-Ar}] (Ar=C6H 5 (12), 2,6-Me2-C6H3 (13), 2,6-iPr2-C6H3 (14), 4-OMe-C6H 4 (15), 3,4-Me2-C6H3 (16), 4-F-C6H4 (17), 4-NO2-C6H4 (18), 4-CN-C6H4 (19), 3,4,5-F3-C 6H2 (20), and C6F5 (21)) in moderate to high yields. The photophysical properties of these new boron complexes largely depend on the substituents present on the aryl rings of their N-arylimino moieties. The complexes bearing electron-withdrawing aniline substituents 17-20 show more intense (e.g., φf=0.71 for Ar=4-CN-C6H4 (19) in THF), higher-energy (blue) fluorescent emission compared to those bearing electron-donating substituents, for which the emission is redshifted at the expense of lower quantum yields (φf=0.13 and 0.14 for Ar=4-OMe-C6H4 (15) and 3,4-Me2-C6H3 (16), respectively, in THF). The presence of substituents bulkier than a hydrogen atom at the 2,6-positions of the aryl groups strongly restricts rotation of this moiety towards coplanarity with the iminopyrrolyl ligand framework, inducing a shift in the emission to the violet region (λmax=410-465-nm) and a significant decrease in quantum yield (φf=0.005, 0.023, and 0.20 for Ar=2,6-Me2-C6H3 (13), 2,6-iPr 2-C6H3 (14), and C6F5 (21), respectively, in THF), even when electron-withdrawing groups are also present. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations have indicated that the excited singlet state has a planar aryliminopyrrolyl ligand, except when prevented by steric hindrance (ortho substituents). Calculated absorption maxima reproduce the experimental values, but the error is higher for the emission wavelengths. Organic light-emitting diodes (OLEDs) have been fabricated with the new boron complexes, with luminances of the order of 3000-cdm-2 being achieved for a green-emitting device. Fluorescent N,N-boron chelate complexes: Mononuclear boron complexes of 2-(N-arylimino)pyrrolyl emit violet to bluish-green colors in solution (see figure, ITO=indium tin oxide, PEDOT:PSS=poly(3,4- ethylenedioxythiophene):poly(styrene sulfonic acid)), depending on the substituents on the N-aryl group. Organic light-emitting diodes have been successfully fabricated with the new boron complexes, achieving luminances of the order of 3000-cdm-2.
