15127-88-5Relevant articles and documents
L-Proline N-oxide dihydrazides as an efficient ligand for cross-coupling reactions of aryl iodides and bromides with amines and phenols
Ding, Zhiqiang,Nie, Nan,Chen, Tian,Meng, Lingxin,Wang, Gongshu,Chen, Zhangpei,Hu, Jianshe
supporting information, (2020/12/21)
A novel catalytic system based on L-proline N-oxide/CuI was developed and applied to the cross-coupling reactions of various N- and O- nucleophilic reagents with aryl iodides and bromides. This strategy featured in the employment of an-proline derived dihydrazides N-oxide compound as the superior supporting ligand. By using this protocol, a variety of products, including N-arylimidazoles, N-arylpyrazoles, N-arylpyrroles, N-arylamines, and aryl ethers, were synthesized with up to 99% yield.
Neutral Cyclometalated Iridium(III) Complexes Bearing Substituted N-Heterocyclic Carbene (NHC) Ligands for High-Performance Yellow OLED Application
Liu, Bingqing,Jabed, Mohammed A.,Guo, Jiali,Xu, Wan,Brown, Samuel L.,Ugrinov, Angel,Hobbie, Erik K.,Kilina, Svetlana,Qin, Anjun,Sun, Wenfang
, p. 14377 - 14388 (2019/11/03)
The synthesis, crystal structure, and photophysics of a series of neutral cyclometalated iridium(III) complexes bearing substituted N-heterocyclic carbene (NHC) ancillary ligands ((CN)2Ir(R-NHC), where CN and NHC refer to the cyclometalating ligand benzo[h]quinoline and 1-phenylbenzimidazole, respectively) are reported. The NHC ligands were substituted with electron-withdrawing or -donating groups on C4′ of the phenyl ring (R = NO2 (Ir1), CN (Ir2), H (Ir3), OCH3 (Ir4), N(CH3)2 (Ir5)) or C5 of the benzimidazole ring (R = NO2 (Ir6), N(CH3)2 (Ir7)). The configuration of Ir1 was confirmed by a single-crystal X-ray diffraction analysis. The ground- and excited-state properties of Ir1-Ir7 were investigated by both spectroscopic methods and time-dependent density functional theory (TDDFT) calculations. All complexes possessed moderately strong structureless absorption bands at ca. 440 nm that originated from the CN ligand based 1π,π*/1CT (charge transfer)/1d,d transitions and very weak spin-forbidden 3MLCT (metal-to-ligand charge transfer)/3LLCT (ligand-to-ligand charge transfer) transitions beyond 500 nm. Electron-withdrawing substituents caused a slight blue shift of the 1π,π*/1CT/1d,d band, while electron-donating substituents induced a red shift of this band in comparison to the unsubstituted complex Ir3. Except for the weakly emissive nitro-substituted complexes Ir1 and Ir6 that had much shorter lifetimes (≤160 ns), the other complexes are highly emissive in organic solutions with microsecond lifetimes at ca. 540-550 nm at room temperature, with the emitting states being predominantly assigned to 3π,π*/3MLCT states. Although the effect of the substituents on the emission energy was insignificant, the effects on the emission quantum yields and lifetimes were drastic. All complexes also exhibited broad triplet excited-state absorption at 460-700 nm with similar spectral features, indicating the similar parentage of the lowest triplet excited states. The highly emissive Ir2 was used as a dopant for organic light-emitting diode (OLED) fabrication. The device displayed a yellow emission with a maximum current efficiency (ηc) of 71.29 cd A-1, a maximum luminance (Lmax) of 32747 cd m-2, and a maximum external quantum efficiency (EQE) of 20.6%. These results suggest the potential of utilizing this type of neutral Ir(III) complex as an efficient yellow phosphorescent emitter.
The Forgotten Nitroaromatic Phosphines as Weakly Donating P-ligands: An N-Aryl-benzimidazolyl Series in RhCl(CO) Complexes
Zhu, Chongwei,Gras, Emmanuel,Duhayon, Carine,Lacassin, Francis,Cui, Xiuling,Chauvin, Remi
supporting information, p. 2845 - 2856 (2017/10/20)
The coordination chemistry of a priori weakly σ-donating nitroaromatic phosphines is addressed through a series of nitro-substituted (N-phenyl-benzimidazol-1-yl)diphenylphosphines in RhI complexes. From a set of seven such phosphines L=Lxyz (′) (x, y, z=0 or 1=number of NO2 substituents at the 5, 6 and N-Ph para positions, respectively), including the non-nitrated parent L000 and its dicationic N-methyl counterpart L000′, three LRhCl(COD) and seven L2RhCl(CO) complexes have been obtained in 72–95 % yield. Despite of a cis orientation of the L and CO ligands, the C=O IR stretching frequency νCO varies in the expected sense, from 1967±1 cm?1 for Lxy0 to 1978±1 cm?1 for Lxy1, and 2005 cm?1 for L000′. The 103Rh NMR chemical shift δRh varies from ?288 ppm for L000 to ?316±1 ppm for L10z or L01z, and ?436 ppm for L000′. The νCO and δRh probes thus reveal moderate but systematic variations, and act as “orthogonal” spectroscopic indicators of the presence of nitro groups on the N-Ph group and the benzimidazole core, respectively. For the dicationic ligand L000′, a tight electrostatic sandwiching of the Rh-Cl bond by the benzimidazole moities is evidenced by X-ray crystallography (RhClδ????CN2 + ≈3.01 ?). Along with the LRhCl(CO) complexes, dinuclear side-products (μ-CO)(RhClL)2 were also obtained in low spectroscopic yield: for the dinitro ligand L=L011, a unique 1:6.7 clathrate structure, with dichloromethane as solvate, is also revealed by X-ray crystallography.
