37570-94-8Relevant academic research and scientific papers
Facile C-N bond cleavage promoted by cuprous oxide: Formation of C-C-coupled biimidazole from its methylene-bridged congener
Sabiah, Shahulhameed,Lee, Chen-Shiang,Hwang, Wen-Shu,Lin, Ivan J. B.
, p. 290 - 293 (2010)
The methylenebis(N-alkylimidazolium) halides are converted to dialkylbiimidazoles by cuprous oxide with concurrent C-N bond cleavage and C-C bond formation. This unusual C-N bond cleavage is proposed to involve a Cu(I)-NHC (N-heterocyclic carbene) complex. The reaction is unique, as it involves C-H bond activation, C-N bond cleavage, and C-C bond formation.
Cyclometalated IrIII Complexes as Mitochondria-Targeted Photodynamic Anticancer Agents
Ouyang, Miao,Zeng, Leli,Qiu, Kangqiang,Chen, Yu,Ji, Liangnian,Chao, Hui
, p. 1764 - 1771 (2017)
Photodynamic therapy (PDT) is an attractive therapeutic modality with high therapeutic efficacy and less side effects compared with other therapies. Herein, we developed a series of cyclometalated IrIII complexes based on 2,2′-biimidazole with different alkyl substitutions (methyl, ethyl, propyl, and butyl). These complexes can efficiently produce singlet oxygen upon light irradiation. In vitro photocytotoxicity towards four cell lines (HeLa, A549, A549R, and LO2) was examined. Ir1–Ir5 show quick penetration of cells, remarkable mitochondrial accumulation, strong phototoxicity, and they exhibit high selectivity between tumor cells and normal cells. With the highest 1O2 quantum yields, Ir5 presents the best PDT efficiency with a high phototoxicity index (PI) value (PI = 150) towards HeLa cells. This work provides a valuable avenue to improve the PDT effect by tuning the lipophilicity and other properties with variation of the alkyl substitution on the photosensitizer. In addition, their satisfying PDT effect to a cisplatin-resistant cell line (A549R) may contribute to the future development of improved chemotherapeutics.
Incrementing Stokes Shifts through the Formation of 2,2′-Biimidazoldiium Salts
Matsumoto, Shoji,Watanabe, Mei,Akazome, Motohiro
, p. 3613 - 3617 (2018)
The formation of biimidazoldiium structures by the introduction of methyl substituents on the N atoms at the 3 and 3′ positions of 2,2′-biimidazoles led to increments in the Stokes shift of these structures. Based on time-dependent density functional theory (TDDFT) calculations, the imidazolium rings become distorted and the N atoms of the imidazolium rings underwent structural changes through sp2 to sp3 rehybridization in the excited states.
Mixing divalent ionic liquids: effects of charge and side-chains
Bakis, Eduards,van den Bruinhorst, Adriaan,Pison, Laure,Palazzo, Ivan,Chang, Thomas,Kjellberg, Marianne,Weber, Cameron C.,Costa Gomes, Margarida,Welton, Tom
, p. 4624 - 4635 (2021/03/15)
We have prepared novel divalent ionic liquids (ILs) based on the bis(trifluoromethylsulfonyl)imide anion where two charged imidazolium groups in the cations are either directly bound to each other or linked by a single atom. We assessed the influence of the side-chain functionality and divalency on their physical properties and on the thermodynamics of mixing. The results indicate that shortening the spacer of a divalent IL reduces its thermal stability and increases its viscosity. Mixtures of divalent and monovalent ILs show small but significant deviations from ideality upon mixing. These deviations appear to depend primarily on the (mis)match of the nature and length of the cation side-chain. The non-ideality imposed by mixing ILs with different side-chains appears to be enhanced by the increase in formal charge of the cations in the mixture.
Effect of ancillary ligands on the properties of diphenylphosphoryl-substituted cationic Ir(iii) complexes
Yu, Hongcui,Liu, Chun,Yu, Zhenni,Zhang, Liyan,Xiu, Jinghai
supporting information, p. 3519 - 3527 (2017/04/13)
A new class of diphenylphosphoryl-substituted cationic cyclometalated Ir(iii) complexes [Ir(POFdFppy)2(N^N)]+PF6- (dFppy = 2-(2,4-difluorophenyl)pyridine) (POF1-POF6) with different N^N ancillary ligands have been synthesized and characterized. The influences of N^N ancillary ligands on the photophysical and electrochemical properties of the Ir(iii) complexes have been investigated systematically. The results demonstrate that the photoluminescence quantum yields (ΦPL) of the complexes are dependent on the N^N ancillary ligands. POF1-POF3 equipped with phenanthroline or bipyridine ancillary ligands exhibit intense emission bands at 465-497 nm and high ΦPL in the range of 56-61% in CH2Cl2. The biimidazole-type complexes POF4-POF6 exhibit an obvious substituent effect on the photophysical and electrochemical properties. Although the emission spectra of POF4 and POF5 show similar fine structures, the ΦPL of POF5 bearing two methyl groups at the biimidazole moiety is remarkably lower (5%) than that of POF4 (45%, unmodified biimidazole). POF6 bearing two phenyl groups at the biimidazole moiety exhibits a red-shift and a weak emission band, and an extremely low ΦPL (3%). However, the photoluminescence quantum yields of POF5 and POF6 (35% and 41% in EC film, 40% and 65% in neat film, respectively) in the film increase effectively in comparison to those in solution. Cyclic voltammetry shows further that the structure of the ancillary ligand affects the redox properties. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were performed to provide insights into the electronic structures of POF1-POF6. POF1 bearing a 1,10-phenanthroline moiety demonstrates the highest oxygen sensitivity.
Synthesis of 2,2′-bIImidazole-based platinum(II) polymetallaynes and tuning their fluorescent response behaviors to Cu2+ ions through optimizing the configuration of the organic spacers and steric effect
Zhang, Huiming,Yan, Xiaogang,Zhao, Jiang,Yang, Xiaolong,Huang, Zuan,Zhou, Guijiang,Wu, Yong
, p. 88758 - 88766 (2015/11/09)
Under controlled conditions, platinum(ii) polymetallaynes with different 2,2′-biimidazole-based organic spacers have been synthesized readily. Their photophysical properties and fluorescent response behaviors to Cu2+ ions have been investigated in detail. By adjusting both the configuration of the 2,2′-biimidazole-based spacers and the steric effect, the fluorescent response behaviors of the polymetallaynes to Cu2+ ions can be tuned dramatically. The fluorescent signal from the polymetallayne with an optimized structure can be quenched rapidly by Cu2+ ions with a high Stern-Volmer constant KSV of ca. 6.8 × 104 M-1 and a low detecting limit (DL) of ca. 0.99 ppm. These results not only highlight the great potential of these polymetallaynes as novel Cu2+ sensors, but also provide new strategies for optimizing the sensing abilities of the 2,2′-biimidazole-based ion sensors.
Synthesis of cationic iridium(III) complexes with high quantum yield via enhancing the steric hindrance of ligands
Shan, Guo-Gang,Li, Hai-Bin,Mu, Zhong-Cheng,Zhu, Dong-Xia,Su, Zhong-Min,Liao, Yi
supporting information; scheme or table, p. 27 - 35 (2012/03/13)
A series of cationic Ir(III) complexes 1a-4a functionalized with carbazole-9-yl-n-butyl group (CZB) were designed and synthesized. An investigation of their photophysical properties showed that the attachment of CZB moiety into the complexes resulted in large improvement in the photoluminescence quantum yield (PLQY) of solid film although the emission spectra and excited-state character presented little change compared with those of the parent complexes. Besides, the functionalized complexes also exhibited good thermal stability and film-forming property. In light of our quantum chemical calculations and X-ray data, these advantages of functionalized complexes mainly derived from the CZB moiety which was superior in reducing the intermolecular interaction and inhibiting the quenching process. Furthermore, to verify our results and design cationic Ir(III) complexes with much higher efficiency, four Ir(III) complexes G0-G3 were synthesized, in which different number of CZB moieties (from 0 to 3) were introduced into the complexes, respectively. Noticeably, in case of G3, the obvious high neat film PLQY of 43% was obtained. In comparison with its dispersed film, a large retaining percentage (90%) was realized, indicating that the CZB moiety could suppress the quenching of luminescence effectively.
Efficient synthesis of biazoles by aerobic oxidative homocoupling of azoles catalyzed by a copper(i)/2-pyridonate catalytic system
Zhu, Mingwen,Fujita, Ken-Ichi,Yamaguchi, Ryohei
supporting information; experimental part, p. 12876 - 12878 (2012/02/03)
A highly efficient and convenient CuCl/2-pyridonate catalytic system for oxidative homocoupling of azoles affording a biazole product has been developed. With this system, a variety of biazoles have been effectively synthesized in good to excellent yields
An efficient and convenient Cu(OAc)2/air mediated oxidative coupling of azoles via C-H activation
Li, Yan,Jin, Jun,Qian, Weixing,Bao, Weiliang
supporting information; experimental part, p. 326 - 330 (2010/02/16)
An efficient and convenient approach to construct C-C bonds at the 2-position of azoles via Cu(OAc)2/air mediated oxidative homo- and cross-coupling reaction was reported. The corresponding products were obtained in good to excellent yield.
New asymmetric synthesis of protein farnesyltransferase inhibitors via palladium-catalyzed cross-coupling reactions of 2-iodo-imidazoles
Kerherve, Jennifer,Botuha, Candice,Dubois, Joelle
supporting information; experimental part, p. 2214 - 2222 (2009/09/04)
Palladium catalyzed cross-coupling reactions of 2-iodoimidazole have been studied to synthesize imidazole-containing protein farnesyltransferase inhibitors. The Suzuki coupling reaction proved to be very efficient to introduce functionalized alkyl chains at the 2-position of the imidazole ring and a new synthesis of the required alkenylboronates was realised by a reaction of cross metathesis. Asymmetric synthesis of allyl succinic derivatives allowed us to synthesize chiral protein farnesyltransferase inhibitors through Suzuki coupling and to determine the influence of the stereochemistry of our inhibitors on the enzymatic activity.
