Tag: 200-300

《Fabrication and Application of Graphene Supported Diimine-Palladium Complex Catalyst for Organic Synthesis》 was published in ChemistrySelect in 2020. These research results belong to Sun, Yunlong; Li, Tian. Name: 2,6-Dibromopyridine The article mentions the following:

In this paper, a diimine palladium complex with suitable steric hindrance of iso-Pr groups and electron supply provided excellent protection for palladium active centers was synthesized and anchored on graphene oxide (GO) to obtain a reusable heterogeneous catalyst (Pd-DI@GO). The XPS results confirmed the effective loading of palladium and the interaction between palladium and ligand. The ICP-AES data verified the Pd content of catalyst was 5.04 wt% and confirmed extremely small amount Pd leaching in Suzuki reaction (<1 ppm). The Pd-DI@GO could catalyze Suzuki reaction and C-H direct arylation reaction of aryl bromides and arylboronic acids/heterocycles to afford biaryls R-R1 [R = Ph, 4-MeC6H4, 2-MeOC6H4, etc.; R1 = Ph, 1-naphthyl, 2-pyridyl, etc] and R2-R3 [R2 = Ph, 4-ClC6H4, 4-tBuC6H4, etc. R3 = 2,4-(Me)2-5-thiazolyl, 2-Me-5-thiazolyl, 4-Me-5-thiazolyl] with high yields. Notably, the Pd-DI@GO could be recycled after Suzuki reaction via filtration or centrifugation easily, presented a yield above 90% for the 4th run. After reading the article, we found that the author used 2,6-Dibromopyridine(cas: 626-05-1Name: 2,6-Dibromopyridine)

2,6-Dibromopyridine(cas: 626-05-1) belongs to pyridine. Pyridine is very deactivated towards electrophilic substitution with respect to benzene. For this reason classical formylation, using methods such as the Gattermann or Vilsmeier reactions, are not generally successful. Name: 2,6-Dibromopyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Computed Properties of C12H10Cl2N2On May 30, 2000, Wu, Xufeng; Fraser, Cassandra L. published an article in Macromolecules. The article was 《Architectural Diversity via Metal Template-Assisted Polymer Synthesis: A Macroligand Chelation Approach to Linear and Star-Shaped Polymeric Ruthenium Tris(bipyridine) Complexes》. The article mentions the following:

Polymeric metal complexes were constructed by combining living polymerization techniques with coordination chem. These metal-centered linear and star-shaped materials combine the film-forming properties of polymers with optical and other features of metal complexes. A metal template approach offers a versatile alternative to the metallo-initiator method previously employed to generate Ru tris(bipyridine)-centered polystyrenes. Specifically, 4,4′-bis(chloromethyl)-2,2′-bipyridine and 4-chloromethyl-2,2′-bipyridine were utilized as initiators for both the bulk and solution polymerization of styrene using atom transfer radical polymerization (ATRP). Narrow dispersity polystyrenes with bipyridine (bpy) binding sites at the end (bpyPS) or center (bpyPS2) of the chains result. These bpyPSn macroligands were chelated to Ru precursor complexes, RuL2Cl2 (L = bpy, phen) or Ru(DMSO)4Cl2, to form complexes with one or three bpyPSn macroligands, resp. Linear polymers, [RuL2(bpyPSn)]2+, with Ru chromophores at the end or center of the chains, and Ru-centered star-shaped polymers, [Ru(bpyPSn)3]2+, with three and six arms were produced. In all cases, dehalogenation with AgPF6 was crucial for efficient macroligand chelation. The relative efficiency of these reactions was estimated by UV/vis spectroscopy. Mol. weight determination by GPC was coupled with in-line diode array UV/vis spectroscopy to confirm the presence of the Ru chromophores in the eluting polymer fractions. The convergent macroligand chelation approach to star-shaped polymeric metal complexes typically works best for polymers of low to moderate mol. weights (<∼65K), with higher mol. weights possible for systems with a single macroligand coordinated. Specific mol. weight thresholds encountered are determined by the number of macroligands, the position of the bpy on the polystyrene chain, and the total number of arms emanating from the metal core. In the part of experimental materials, we found many familiar compounds, such as 4,4'-Bis(chloromethyl)-2,2'-bipyridine(cas: 138219-98-4Computed Properties of C12H10Cl2N2)

4,4′-Bis(chloromethyl)-2,2′-bipyridine(cas: 138219-98-4) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. Computed Properties of C12H10Cl2N2 Pyridine has a conjugated system of six π electrons that are delocalized over the ring.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Ruthenium Tris(bipyridine)-Centered Linear and Star-Shaped Polystyrenes: Making Atom Transfer Radical Polymerization and Metal Complex Initiators Compatible》 was written by Wu, Xufeng; Collins, James E.; McAlvin, John E.; Cutts, Russell W.; Fraser, Cassandra L.. Electric Literature of C12H10Cl2N2 And the article was included in Macromolecules on April 24 ,2001. The article conveys some information:

The ligand derivative, 4,4′-bis(chloromethyl)-2,2′-bipyridine (bpy(CH2Cl)2), and Ru(II) complexes with 2, 4, or 6 pendant halomethyl groups were employed as initiators in the atom transfer radical polymerization (ATRP) of styrene to produce linear and star polymers with ligands and chromophores at discrete positions in the polymer architectures. With the metalloinitiators, [Ru(bpy)n{bpy(CH2Cl)2}3-n](PF6)2 (n = 0, 1, 2), styrene polymerizations were run in bulk monomer, as well as in the presence of small amounts of anisole (14% volume/volume vs styrene), employing either CuCl/2bpy(C13H27)2 or CuBr/1,1,4,7,10,10-hexamethyltriethylenetetraamine (HMTETA) as the ATRP catalyst. Kinetics experiments were performed to determine the level of mol. weight control that is attainable in these polymerizations With the former catalyst and when anisole is added, reactions exhibited increased control for the metalloinitiators and ligand initiators. Since the dicationic metalloinitiators exhibited limited solubility, which correlated with poor initiation, attempts were made to improve the compatibility of metalloreagents in the nonpolar ATRP medium. Di- and tetrafunctional metalloinitiators modified with alkyl chains, [Ru{bpy(C13H27)2}n{bpy(CH2Cl)2}3-n](PF6)2 (n = 1, 2), displayed improved initiation and mol. weights closer to targeted values. However, attempts to improve the solubility of the homoleptic complex, [Ru{bpy(CH2Cl)2}3](PF6)2 by substituting a BAr’4- counterion for PF6- did not enhance mol. weight control. The use of DMF, a more polar solvent, in place of anisole did increase solubility of the hexafunctional initiator; at low monomer conversion, polydispersities were lower in DMF vs anisole. Polymers were characterized by gel permeation chromatog. (GPC) with refractive index (RI) and multiangle laser light scattering (MALLS) detection, by UV/vis spectroscopy to confirm the covalent attachment of Ru(II) chromophores to polystyrene chains, and by modulated differential scanning calorimetry (MDSC). After reading the article, we found that the author used 4,4′-Bis(chloromethyl)-2,2′-bipyridine(cas: 138219-98-4Electric Literature of C12H10Cl2N2)

4,4′-Bis(chloromethyl)-2,2′-bipyridine(cas: 138219-98-4) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. Electric Literature of C12H10Cl2N2The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

HPLC of Formula: 626-05-1In 2020 ,《Iridium(III) Complexes Bearing a Formal Tetradentate Coordination Chelate: Structural Properties and Phosphorescence Fine-Tuned by Ancillaries》 appeared in Inorganic Chemistry. The author of the article were Yuan, Yi; Gnanasekaran, Premkumar; Chen, Yu-Wen; Lee, Gene-Hsiang; Ni, Shao-Fei; Lee, Chun-Sing; Chi, Yun. The article conveys some information:

Synthesis of the multidentate coordinated chelate N3C-H2, composed of a linked functional pyridyl pyrazole fragment plus a peripheral Ph and pyridyl unit, was obtained using a multistep protocol. Preparation of Ir(III) metal complexes bearing a N3C chelate in the tridentate (κ3), tetradentate (κ4), and pentadentate (κ5) modes was executed en route from two nonemissive dimer intermediates [Ir(κ3-N3CH)Cl2]2 (1) and [Ir(κ4-N3C)Cl]2 (2). Next, a series of mononuclear Ir(III) complexes with the formulas [Ir(κ4-N3C)Cl(py)] (3), [Ir(κ4-N3C)Cl(dmap)] (4), [Ir(κ4-N3C)Cl(mpzH)] (5), and [Ir(κ4-N3C)Cl(dmpzH)] (6), as well as diiridium complexes [Ir2(κ5-N3C)(mpz)2(CO)(H)2] (7) and [Ir2(κ5-N3C)(dmpz)2(CO)(H)2] (8), were obtained upon treatment of dimer 2 with pyridine (py), 4-dimethylaminopyridine (dmap), 4-methylpyrazole (mpzH), and 3,5-dimethylpyrazole (dmpzH), resp. These Ir(III) metal complexes were identified using spectroscopic methods and by x-ray crystallog. anal. of representative derivatives 3, 5, and 7. Their photophys. and electrochem. properties were investigated and confirmed by the theor. simulations. Notably, green-emitting organic light-emitting diode (OLED) on the basis of Ir(III) complex 7 gives a maximum external quantum efficiency up to 25.1%. This result sheds light on the enormous potential of this tetradentate coordinated chelate in the development of highly efficient iridium complexes for OLED applications. Preparation of Ir(III) complexes bearing tailor-made multidentate N3C chelate are reported, from which a green-emitting OLED with a maximum EQE of 25.1% was successfully fabricated using diiridium complex 7. The experimental process involved the reaction of 2,6-Dibromopyridine(cas: 626-05-1HPLC of Formula: 626-05-1)

2,6-Dibromopyridine(cas: 626-05-1) belongs to pyridine. Pyridine and pyridine-derived structures are privileged pharmacophores in medicinal chemistry and an essential functionality for organic chemists. As the prototypical π-deficient heterocycle, pyridine illustrates distinctive chemistry as both substrate and reagent. HPLC of Formula: 626-05-1

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Application In Synthesis of 2,6-DibromopyridineIn 2021 ,《Deoxygenative coupling of 2-aryl-ethanols catalyzed by unsymmetrical pyrazolyl-pyridinyl-triazole ruthenium》 appeared in Molecular Catalysis. The author of the article were Cao, Fei; Duan, Zheng-Chao; Zhu, Haiyan; Wang, Dawei. The article conveys some information:

A pyrazolyl-pyridinyl-triazole Ru complex was synthesized from unsym. pyrazolyl-pyridinyl-triazole (PPT) skeleton ligand and characterized through X-ray crystallog. The corresponding heterogeneous pyrazolyl-pyridinyl-triazole Ru complexes on γ-Al2O3 were characterized through SEM, TEM, XRD and XPS. Both homogeneous and heterogeneous Ru catalysts revealed high activity for deoxygenative homocoupling of 2-arylethanols to obtain arylalkenes RCH=CHCH2R [R = Ph, 4-FC6H4, 2-thienyl, etc.]. In the experimental materials used by the author, we found 2,6-Dibromopyridine(cas: 626-05-1Application In Synthesis of 2,6-Dibromopyridine)

2,6-Dibromopyridine(cas: 626-05-1) belongs to pyridine. The basicity and metallophilic high donor number of these π-deficient systems has long favored them as ligands in metal catalysis. The last decade saw pyridine assume a stronger role as functional group for directed C–H oxidation/activation.Application In Synthesis of 2,6-Dibromopyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Yu, Yi; Mallick, Suman; Wang, Mao; Boerjesson, Karl published their research in Nature Communications in 2021. The article was titled 《Barrier-free reverse-intersystem crossing in organic molecules by strong light-matter coupling》.HPLC of Formula: 624-28-2 The article contains the following contents:

Strong light-matter coupling provides the means to challenge the traditional rules of chem. In particular, an energy inversion of singlet and triplet excited states would be fundamentally remarkable since it would violate the classical Hund’s rule. An organic chromophore possessing a lower singlet excited state can effectively harvest the dark triplet states, thus enabling 100% internal quantum efficiency in elec. pumped light-emitting diodes and lasers. Here we demonstrate unambiguously an inversion of singlet and triplet excited states of a prototype mol. by strong coupling to an optical cavity. The inversion not only implies that the polaritonic state lies at a lower energy, but also a direct energy pathway between the triplet and polaritonic states is opened. The intrinsic photophysics of reversed-intersystem crossing are thereby completely overturned from an endothermic process to an exothermic one. By doing so, we show that it is possible to break the limit of Hund’s rule and manipulate the energy flow in mol. systems by strong light-matter coupling. Our results will directly promote the development of organic light-emitting diodes based on reversed-intersystem crossing. Moreover, we anticipate that it provides the pathway to the creation of elec. pumped polaritonic lasers in organic systems. The experimental process involved the reaction of 2,5-Dibromopyridine(cas: 624-28-2HPLC of Formula: 624-28-2)

2,5-Dibromopyridine(cas: 624-28-2) belongs to pyridine. Pyridine’s structure is isoelectronic with that of benzene, but its properties are quite different. Pyridine is completely miscible with water, whereas benzene is only slightly soluble. Like all hydrocarbons, benzene is neutral (in the acid–base sense), but because of its nitrogen atom, pyridine is a weak base.HPLC of Formula: 624-28-2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The author of 《Sulfide analogues of flupirtine and retigabine with nanomolar KV7.2/KV7.3 channel opening activity》 were Bock, Christian; Surur, Abdrrahman S.; Beirow, Kristin; Kindermann, Markus K.; Schulig, Lukas; Bodtke, Anja; Bednarski, Patrick J.; Link, Andreas. And the article was published in ChemMedChem in 2019. Category: pyridine-derivatives The author mentioned the following in the article:

The potassium channel openers flupirtine and retigabine have proven to be valuable analgesics or antiepileptics. Their recent withdrawal due to occasional hepatotoxicity and tissue discoloration, resp., leaves a therapeutic niche unfilled. Metabolic oxidation of both drugs gives rise to the formation of electrophilic quinones. These elusive, highly reactive metabolites may induce liver injury in the case of flupirtine and blue tissue discoloration after prolonged intake of retigabine. We examined which structural features can be altered to avoid the detrimental oxidation of the aromatic ring and shift oxidation toward the formation of more benign metabolites. Structure-activity relationship studies were performed to evaluate the KV7.2/3 channel opening activity of 45 derivatives Sulfide analogs were identified that are devoid of the risk of quinone formation, but possess potent KV7.2/3 opening activity. For example, flupirtine analog 3-(3,5-difluorophenyl)-N-(6-(isobutylthio)-2-(pyrrolidin-1-yl)pyridin-3-yl)propanamide (48) has 100-fold enhanced activity (EC50=1.4 nM), a vastly improved toxicity/activity ratio, and the same efficacy as retigabine in vitro. In the experiment, the researchers used 2-(Bromomethyl)pyridine hydrobromide(cas: 31106-82-8Category: pyridine-derivatives)

2-(Bromomethyl)pyridine hydrobromide(cas: 31106-82-8) belongs to pyridine. Pyridine is very deactivated towards electrophilic substitution with respect to benzene. For this reason classical formylation, using methods such as the Gattermann or Vilsmeier reactions, are not generally successful. Category: pyridine-derivatives

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The author of 《Fluorescent probes for detecting glutathione: Bio-imaging and two reaction mechanisms》 were Xia, Ying; Zhang, Huihui; Zhu, Xiaojiao; Fang, Min; Yang, Mingdi; Zhang, Qiong; Li, Xiaowu; Zhou, Hongping; Yang, Xingyuan; Tian, Yupeng. And the article was published in Dyes and Pigments in 2019. Product Details of 31106-82-8 The author mentioned the following in the article:

A series of compounds (W1-W8) based on triphenylamine with -C=N- or -NH- group, were designed and studied by fluorescence emission spectra and DFT/TDDFT calculations Probes W1-W4 were selectively leveraged to sensitively detect glutathione by two distinct reaction mechanisms, thereinto, W1-W2 featured a convenient detection for glutathione using hydrolysis and W3-W4 utilized displacement to probe glutathione possessing sensitivity and practicability. Compound W5-W8 here provided an avenue for understanding structure-property relationship. Taken considerations for toxicity and biocompatibility together, W1-W4 showed great advance for endogenously and exogenously imaging GSH in living cells. After reading the article, we found that the author used 2-(Bromomethyl)pyridine hydrobromide(cas: 31106-82-8Product Details of 31106-82-8)

2-(Bromomethyl)pyridine hydrobromide(cas: 31106-82-8) belongs to pyridine. Pyridine is very deactivated towards electrophilic substitution with respect to benzene. For this reason classical formylation, using methods such as the Gattermann or Vilsmeier reactions, are not generally successful. Product Details of 31106-82-8

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2019,Dalton Transactions included an article by Ding, Tao; Zhang, Sheng; Zhang, Weiqiang; Zhang, Guofang; Gao, Zi-Wei. Application In Synthesis of 2,6-Dibromopyridine. The article was titled 《Highly selective C2H2 and CO2 capture and magnetic properties of a robust Co-chain based metal-organic framework》. The information in the text is summarized as follows:

A robust Co-based metal-organic framework, [Co3(L)(OH)2(H2O)4]·2DMF·2H2O (1), was synthesized under solvothermal conditions using pyridyl-decorated tetracarboxylic acid, 2,6-di(2′,5′-dicarboxylphenyl)pyridine (H4L). Structural anal. demonstrates that 1 is a 3D framework based on 1D alternate Co4 chain units. The desolvated structure of 1a contains 1D open channels with a highly polar pore surface decorated with open metal sites, μ3-OH group and pyridyl group sites, exhibiting multipoint interactions between C2H2 and CO2 mols. The framework efficiently takes up C2H2 and CO2 with significant selectivity for C2H2 and CO2 over CH4. In addition, the magnetic properties of 1 were studied and it showed a slow freezing process. In the part of experimental materials, we found many familiar compounds, such as 2,6-Dibromopyridine(cas: 626-05-1Application In Synthesis of 2,6-Dibromopyridine)

2,6-Dibromopyridine(cas: 626-05-1) belongs to pyridine. Pyridines are often used as catalysts or reagents; particular notice has been paid recently to how pyridine coordinates to metal centers enabling a wide range of valuable reactions. Application In Synthesis of 2,6-Dibromopyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Li, Maoqiu; Yu, Junting; Liu, Denghui; Tan, Shuai; Yang, Xiaoqin; Cao, Liqin; Tan, Yuna; Cao, Jiamin; Tan, Hua; Wang, Yafei; Zhu, Weiguo published an article in 2021. The article was titled 《Enhancing the efficiency of near-infrared iridium (III) complexes-based OLEDs by auxiliary ligand functionalizationã€? and you may find the article in Synthetic Metals.SDS of cas: 29682-15-3 The information in the text is summarized as follows:

In order to enhance the charge balance of organic near IR (NIR) electroluminescent devices, an ancillary ligand of pic-SCz which was covalently linking the bipolar group SCz (composed of PS (S) and tBuCz (Cz)) to pic (SCz=3,6-di-tert-butyl-9-(4-(phenylsulfonyl)phenyl)-9H-carbazole; PS = Ph sulfone; tBuCz = 3,6-di-tert-butylcarbazole; pic= 2-picolinic acid) was developed for iridium (III) complex (TPA-BTz-Iq)2Ir(pic-SCz). Compared with parent complex (TPA-BTz-Iq)2Irpic, the photophys. and electroluminescent properties of (TPA-BTz-Iq)2Ir(pic-SCz) were improved by introducing Cz as hole transporting unit and PS as electron transporting unit. In phosphorescent organic light emitting devices (OLEDs), using (TPA-BTz-Iq)2Ir(pic-SCz) as the luminescent dopant, we obtained a maximum external quantum efficiency (EQEmax) of 0.95% at the wavelength of 712 nm. This is 3.28 times as much as that of (TPA-BTz-Iq)2Irpic (EQEmax is 0.29% at 712 nm). The experimental part of the paper was very detailed, including the reaction process of Methyl 5-bromopicolinate(cas: 29682-15-3SDS of cas: 29682-15-3)

Methyl 5-bromopicolinate(cas: 29682-15-3) belongs to pyridine. When pyridine is adsorbed on oxide surfaces or in porous materials, the following species are commonly observed: (i) pyridine coordinated to Lewis acid sites, (ii) pyridine H-bonded to weakly acidic hydroxyls, and (iii) protonated pyridine. At high coverage, physisorbed pyridine and protonated dimers can also be observed.SDS of cas: 29682-15-3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem