15862-18-7Relevant articles and documents
Synthesis of new bis-BINOLs linked by a 2,2e′-bipyridine bridge
Bai, Xiao-Li,Liu, Xu-Dong,Wang, Mang,Kang, Chuan-Qing,Gao, Lian-Xun
, p. 458 - 464 (2005)
A series of new C2-symmetric chiral ligands 8, 9, 11 and 12, consisting of two binaphthyl units linked by a 2,2′-bipyridine bridge, has been synthesized via Suzuki cross-coupling reactions.
A straightforward synthesis of 5-bromo and 5,5'-dibromo-2,2'-bipyridines
Romero,Ziessel
, p. 6471 - 6474 (1995)
We herein report on the selective synthesis of 5-bromo-2,2'-bipyridine 2 and 5,5'-dibromo-2,2'-bipyridine 3 by direct bromination of 2,2'-bipyridine hydrobromide salt 1, as well as by radical decarboxylative bromination of the corresponding acid chlorides.
Cyclometalated iridium(III) complexes as photosensitizers for long-range electron transfer: Occurrence of a coulomb barrier
Hanss, David,Freys, Jonathan C.,Bernardinelli, Gerald,Wenger, Oliver S.
, p. 4850 - 4859 (2009)
Six cyclometalated iridium(III) complexes were investigated to assess their potential as photosensitizers for long-range electron transfer, and two of them were incorporated directly into covalent donor-bridge-acceptor molecules. The influence of ligarid substitutions on the excited-state properties and the photoredox behavior of the iridium complexes was explored by optical absorption, steady-state and time-resolved luminescence spectroscopy, as well as by electrochemical methods. Bimolecular electron transfer between the photoexcited complexes and 10-methylphenothiazine and methylviologen was found to be only weakly dependent on the ligand substitutions. Intramolecular long-range electron transfer from phenothiazine to photoexcited iridium(III) in the dyads is slow due to the occurrence of a Coulomb barrier. Consequently, an electron-transfer photoproduct is only observable in the transient absorption spectrum, of a donorbridge-acceptor molecule with a fluorinated photosensitizer that exhibits a very long excited-state lifetime. A flashquench technique is necessary for detection of an electrontransfer product in the dyad with a non-fluorinated photosensitizer. The occurrence of a Coulomb barrier associated with intramolecular (excited-state) long-range electron transfer in the dyads with cyclometalated iridium(III) photosensitizers represents an important difference to previously investigated similar donor-bridge-acceptor molecules with photosensitizers based on d6 metal diimine complexes.
Development of high dielectric polyimides containing bipyridine units for polymer film capacitor
Peng, Xinwen,Xu, Wenhui,Chen, Linlin,Ding, Yichun,Xiong, Tianrou,Chen, Shuiliang,Hou, Haoqing
, p. 93 - 98 (2016)
Polymer dielectrics with high dielectric constant, low dielectric loss, high breakdown strength, and high temperature capability are attractive for applications such as capacitive energy-storage. Commercially available polymer dielectrics such as biaxially oriented polypropylene (BOPP), poly(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN), polycarbonate (PC), and poly(vinylidene) fluoride (PVDF) can be just operated below 200 °C. Great effort has been put into exploring high temperature polymer dielectrics to fulfill the demand of high temperature applications, such as the aerospace and military power supply. In this study, a series of polyimides containing bipyridine units with good dielectric performance and high temperature capability were prepared by using a newly synthesized diamine monomer, (5,5′-bis [(4-amino) phenoxy]-2,2′-bipyridine (BPBPA)). These polyimides possessed high dielectric constant of the as-synthesized polyimides can be up to7.2, the dielectric loss was 3. Furthermore, the polyimides exhibited high glass transition temperature (Tg) of 275–320 °C and tensile strengths of 175–221 MPa. These obtained polyimides promise potential applications in high temperature flexible polymer film capacitor operated at high temperature.
π-conjugated chelating polymers with charged iridium complexes in the backbones: Synthesis, characterization, energy transfer, and electrochemical properties
Liu, Shu-Juan,Zhao, Qiang,Chen, Run-Feng,Deng, Yun,Fan, Qu-Li,Li, Fu-You,Wang, Lian-Hui,Huang, Chun-Hui,Huang, Wei
, p. 4351 - 4361 (2006)
A series of π-conjugated chelating polymers with charged iridium (Ir) complexes in the backbones were synthesized by a Suzuki polycondensation reaction, leading to homogeneous polymeric materials that phosphoresce red light. The fluorene and bipyridine (bpy) segments were used as polymer backbones. 5.5′-Dibromobipyridine served as a ligand to form a charged iridium complex monomer with 1-(9′9-dioctylfluorene-2-yl)isoquinoline (Fiq) as the cyclometalated ligand. Chemical and photophysical characterization confirmed that Ir complexes were incorporated into the backbones as one of the repeat units by means of the 5.5′-dibromobipyridine ligand. Chelating polymers showed almost complete energy transfer from the host fluorene segments to the guest Ir complexes in the solid state when the feed ratio was 2 mol%. In the films of the corresponding blend system, however, energy transfer was not complete even when the content of Ir complexes was as high as 16 mol%. Both intra- and in termolecular energy-transfer processes existed in this host-guest system, and the intramolecular energy transfer was a more efficient process. All chelating polymers displayed good thermal stability, redox reversibility, and film formation. These chelating polymers also showed more efficient energy transfer than the corresponding blended system and the mechanism of incorporation of the charged Ir complexes into the π-conjugated polymer backbones efficiently avoided the intrinsic problems associated with the blend system, thus offering promise in optoelectronic applications.
Cu(ii)Cl2containing bispyridine-based porous organic polymer support preparedviaalkyne-azide cycloaddition as a heterogeneous catalyst for oxidation of various olefins
Choi, Hye Min,Lee, Suk Joong,Yoon, Jongho
supporting information, p. 9149 - 9152 (2020/06/17)
A new type of porous organic polymer (POP) based heterogeneous catalystCu-POPwas prepared by immobilizing Cu(ii)Cl2into bpy containing POP preparedviaalkyne-azide cycloaddition. This new catalyst showed efficient catalytic activities and outstanding reusability. Remarkably, one batch ofCu-POPwas continuously used for all olefins without losing its activity by simply washing.
Merging Photoredox and Organometallic Catalysts in a Metal–Organic Framework Significantly Boosts Photocatalytic Activities
Zhu, Yuan-Yuan,Lan, Guangxu,Fan, Yingjie,Veroneau, Samuel S.,Song, Yang,Micheroni, Daniel,Lin, Wenbin
supporting information, p. 14090 - 14094 (2018/10/15)
Metal–organic frameworks (MOFs) have been extensively used for single-site catalysis and light harvesting, but their application in multicomponent photocatalysis is unexplored. We report here the successful incorporation of an IrIII photoredox catalyst and a NiII cross-coupling catalyst into a stable Zr12 MOF, Zr12-Ir-Ni, to efficiently catalyze C?S bond formation between various aryl iodides and thiols. The proximity of the IrIII and NiII catalytic components to each other (ca. 0.6 nm) in Zr12-Ir-Ni greatly facilitates electron and thiol radical transfers from Ir to Ni centers to reach a turnover number of 38 500, an order of magnitude higher than that of its homogeneous counterpart. This work highlights the opportunity in merging photoredox and organometallic catalysts in MOFs to effect challenging organic transformations.
