65039-06-7Relevant academic research and scientific papers
Cationic Iridium(III) complexes with two carbene-based cyclometalating ligands: Cis versus trans isomers
Monti, Filippo,La Placa, Maria Grazia I.,Armaroli, Nicola,Scopelliti, Rosario,Gr?tzel, Michael,Nazeeruddin, Mohammad Khaja,Kessler, Florian
, p. 3031 - 3042 (2015)
A series of cationic iridium(III) complexes with two carbene-based cyclometalating ligands and five different N^N bipyridine and 1,10-phenanthroline ancillary ligands is presented. For the first time-in the frame of a rarely studied class of bis(heterolep
Phenyl and thienyl functionalized imidazolium iodides for highly efficient quasi-solid-state dye-sensitized solar cells
Zhang, Meirong,Jin, Zhitong,Feng, Chuanqi,Wang, Min,Wang, Zhong-Sheng
, p. 16976 - 16983 (2017)
To enhance the ionic conductivity of imidazolium iodide based ionic conductors, the π conjugation of the imidazolium cation is expanded via N-substitution with aromatic groups of phenyl and thienyl. Three ionic conductors (ICs) of MPhII, MT2II
ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES
-
Paragraph 0144-0146, (2021/04/17)
Provided is a compound of Formula Ir(LA)(LB)(LC), wherein LA is a ligand of LB is a ligand of and LC is a ligand of wherein a structure of is fused to the ligand LB of Formula II
NHC ligand-based half-sandwich iridium complexes: synthesis, structure and catalytic activity in acceptorless dehydrogenation and transfer hydrogenation
Deng, Wei,Jin, Yan,Li, Rong-Jian,Liu, Zhen-Jiang,Wang, Yang,Yao, Zi-Jian
, p. 19002 - 19010 (2021/10/29)
A set of neutral C,C-chelate half-sandwich iridium(iii) complexes have been prepared with NHC ligands that contain pendant aromatic rings as potentially chelating donor sites. The catalytic activity of such iridium complexes has been investigated for the acceptorless dehydrogenation (AD) reactions of alcohols and for the transfer hydrogenation reactions of ketones. The prepared iridium(iii) complexes show excellent catalytic activity for AD reactions of a wide range of secondary alcohols, and they are also shown to be effective for the synthesis of aldehydes from primary alcohols without the observation of undesired byproducts such as esters. Additionally, these complexes are also highly efficient in transfer hydrogenation of ketones and aldehydes, which give the alcohols in good yields under mild conditions. The exact structure and bonding mode of the NHC-based iridium complexes was identified using various spectroscopic methods and single crystal X-ray analysis.
Steric effect of NHC ligands in Pd(II)–NHC-catalyzed non-directed C–H acetoxylation of simple arenes
Mandal, Tanmoy,Yadav, Sudha,Choudhury, Joyanta
, (2021/09/06)
Although there has been a lot of progress in oxidative arene C–H functionalization reactions catalyzed by Pd(II/IV) system, the non-directed, site-selective functionalization of arene molecules is still challenging. It has been established that ligands play a pivotal role in controlling rate- as well as selectivity-determining step in a catalytic cycle involving well-defined metal-ligand bonding. N-heterocyclic carbene (NHC) ligands have had a tremendous contribution in the recent extraordinary success of achieving high reactivity and excellent selectivity in many catalytic processes including cross-coupling and olefin-metathesis reactions. However, the immense potential of these NHC ligands in improving site-selectivity of non-directed catalytic C–H functionalization reactions of simple arenes is yet to be realized, where overriding the electronic bias on deciding selectivity is a burdensome task. The presented work demonstrated an initiative step in this regard. Herein, a series of well-defined discrete [Pd(NHCR′R)(py)I2] complexes with systematically varied degree of spatial congestion at the Pd centre, exerted through the R and R’ substituents on the NHC ligand, were explored in controlling the activity as well as the site-selectivity of non-directed acetoxylation of representative monosubstituted and disubstituted simple arenes (such as toluene, iodobenzene and bromobenzene, naphthalene and 1,2-dichlorobenzene). The resulting best yields were found to be 75% for toluene and 65% for bromobenzene with [Pd(NHCMePh)(py)I2], 75% for iodobenzene and 79% for naphthalene with [Pd(NHCMeMe)(py)I2], and 41% for 1,2-dichlorobenzene with [Pd(NHCCyCy)(py)I2]. Most importantly, with increasing the bulkiness of the NHC ligand in the complexes, the selectivity of the distal C-acetoxylated products in comparison to the proximal ones, was enhanced to a great extent in all cases. Considering the vast library of NHC ligands, this study underscores the future opportunity to develop more strategies to improve the activity and the crucial site-selectivity of C–H functionalization reactions in simple as well as complex organic molecules.
Efficient transfer hydrogenation of carbonate salts from glycerol using water-soluble iridium N-heterocyclic carbene catalysts
Ainembabazi, Diana,Finn, Matthew,Ridenour, James,Voutchkova-Kostal, Adelina,Wang, Kai
supporting information, p. 6093 - 6104 (2020/10/18)
The transfer hydrogenation of CO2and carbonates from biomass-derived alcohols, such as glycerol, to afford formic and lactic acid is a highly attractive path to valorizing two waste streams, and is significantly more thermodynamically favorable than direct carbonate hydrogenation. Expanding on our seminal report of the first homogeneous catalyst for this process, here we show that thermally-robust and water-soluble Ir(i) and Ir(iii) N-heterocyclic carbene (NHC) complexes with sulfonate-functionalized wingtips are highly prolific and robust catalysts for carbonate transfer hydrogenation from glycerol, requiring no additives in aqueous media. The most prolific catalyst of the nine examined, [Ir(NHC-Ph-SO3?)2CO2]Na (cat7), effectively facilitates the reaction at low catalyst loading (10 ppm) at 150 °C using microwave or conventional heating. The cation of the carbonate salt significantly impacts catalytic activity, with highest activity observed with Cs2CO3(27?850 and 13?350 TONs for lactate and formate respectively in 6 hours, compared to 15?400 and 8120 with K2CO3). Catalytic amounts of Cs+were found to significantly enhance activity with K2CO3. Catalyst7is even more prolific with conventional heating under a positive N2pressure, reaching TOFs of >3000 h?1and >2100 h?1respectively for lactate and formate with K2CO3. The high activity of this catalyst compared to non-sulfonated and cyclooctadiene analogs is attributed to a combination of catalyst solubility in aqueous media and presence of π-acceptor carbonyl ligands. A catalytic mechanism is proposed for7involving O-H oxidative addition of glycerol, β-hydride elimination, bicarbonate dehydroxylation, insertion and reductive elimination.
Simple and reactive Ir(i) N-heterocyclic carbene complexes for alkyne activation
Gatus, Mark R. D.,Pernik, Indrek,Tompsett, Joshua A.,Binding, Samantha C.,Peterson, Matthew B.,Messerle, Barbara A.
supporting information, p. 4333 - 4340 (2019/04/01)
Two simple unsymmetrical monometallic Ir(i) complexes with an N-heterocyclic carbene ligand and an analogous bimetallic Ir(i) complex were synthesised. These complexes were found to be extremely active catalysts for a range of C-X (X = N or O) and Si-N bond forming reactions involving alkyne and imine activation for dihydroalkoxylation, hydroamination and hydrosilylation reactions. These catalysts exhibited reaction rates far exceeding those of other Rh(i) and Ir(i) complexes previously reported. In addition, a small change to the ligand design (phenyl vs. mesityl) substantially affected both the reactivity and product selectivity of the catalyst. The Ir(i) complex bearing a mesitylene wingtip provided unprecedented regioselectivity in the dihydroalkoxylation reaction and a new kinetic product from the typical hydrosilylation protocol of 2-benyzlpyrroline to produce an N-silylaminoalkene. Our mechanistic studies indicated that this transformation proceeded via a dehydrogenative coupling mechanism.
Remote coordination approach for electronic tuning of a rhodium(I)-N-heterocyclic carbene (NHC)-complex
Thenarukandiyil, Ranjeesh,Maji, Babulal,Choudhury, Joyanta
supporting information, p. 419 - 423 (2019/01/08)
A simple Lewis acid coordination at the remote binding site installed within a modular N-heterocyclic carbene (NHC) ligated rhodium(I) complex could induce desired electronic influence and thereby enhance the activity of the complex in a model styrene hyd
Cation-π interactions secure aggregation induced emission of planar organic luminophores
Leduskrasts, Kaspars,Kinens, Artis,Suna, Edgars
supporting information, p. 12663 - 12666 (2019/10/28)
The use of non-covalent intermolecular π+-π interactions between quaternary pyridinium or imidazolium cations and aromatic π systems is an efficient approach to achieve AIE in planar purely organic luminophores.
Ionic liquid containing electron-rich, porous polyphosphazene nanoreactors catalyze the transformation of CO2 to carbonates
Huang, Zhangjun,Uranga, Jorge G.,Zhou, Shiliu,Jia, Haiyan,Fei, Zhaofu,Wang, Yefeng,Bobbink, Felix D.,Lu, Qinghua,Dyson, Paul J.
, p. 20916 - 20925 (2018/11/20)
We show that ionic liquids (ILs) interact with electron-rich, porous polyphosphazene (PPZ), to form hybrid PPZ-IL nanoreactors able to simultaneously capture and transform CO2 into carbonates. The PPZ nanospheres swell in organic solvents and e
