Day: October 13, 2022

《Understanding the role of acid-base interactions using architecturally-controlled, pyridyl-bearing sulfonated phenylated polyphenylenes》 was published in Journal of Materials Chemistry A: Materials for Energy and Sustainability in 2020. These research results belong to Xu, Shaoyi; Wu, Yang; Adamski, Michael; Fraser, Kate; Holdcroft, Steven. Related Products of 624-28-2 The article mentions the following:

Acid-base interactions between N-heterocycles and sulfonic acid groups are known to mitigate the excessive swelling of hydrocarbon-based proton exchange polymers, but concurrently reduce the concentration of hydrated protons therein, which lowers proton conductivity We report sulfonated phenylated poly(phenylene) homopolymers designed with similar architecture but with an increasing number of strategically-placed N-atoms in the form of pyridyl units. It is discovered that polymers with 2 or more pyridines per repeat unit do not stoichiometrically neutralize pendent sulfonic acids. For example, four pyridines per repeat unit neutralize the equivalent of ~2 sulfonic acids, resulting in a reduced number of pyridinium (H+)-sulfonate cross links than anticipated. DFT calculations reveal that externally-exposed pyridine groups form a stronger interaction with protons than a sterically-hindered pyridine that affects mech. properties and water sorption. Nonetheless, as the number of N-atoms is increased, the fraction of neutralized -SO3H protons is increased, and the material’s ion exchange capacity, proton conductivity, liquid and vaporous water sorption, dimensional swelling, steady-state water permeability, and transient diffusivity all decrease. With four pyridyl groups per repeating unit, dimensional swelling of the fully hydrated polymer, steady-state water permeability are similar to the Nafion N211 reference material. However, proton conductivities under reduced RH are substantially reduced due to their low water sorption. This work provides insight into tailoring proton exchange membranes via acid-base, self-neutralization for the purpose of controlling their transport properties.2,5-Dibromopyridine(cas: 624-28-2Related Products of 624-28-2) was used in this study.

2,5-Dibromopyridine(cas: 624-28-2) belongs to pyridine. Pyridine and its simple derivatives are stable and relatively unreactive liquids, with strong penetrating odours that are unpleasant.Related Products of 624-28-2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Crystal structure of 2,6-bis(3-hydroxy-3-methylbut-1-yn-1-yl)pyridine monohydrate》 was published in Acta Crystallographica, Section E: Crystallographic Communications in 2020. These research results belong to Koizumi, Take-aki; Takata, Toshikazu. Product Details of 626-05-1 The article mentions the following:

In the title pyridine derivative, C15H17NO2·H2O, the two OH groups are oriented in directions opposite to each other with respect to the plane of the pyridine ring. In the crystal, hydrogen bonds between the pyridine mol. and the water mol., viz. Ohydroxy-H · · · Owater, Ohydroxy-H · · · Ohydroxy, Owater-H · · · Ohydroxy and Owater-H· · · Npyridine, result in the formation of a ribbon-like structure running along [011]. In the part of experimental materials, we found many familiar compounds, such as 2,6-Dibromopyridine(cas: 626-05-1Product Details of 626-05-1)

2,6-Dibromopyridine(cas: 626-05-1) 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.Product Details of 626-05-1

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Acetylene-linked conjugated polymers for sacrificial photocatalytic hydrogen evolution from water》 was written by Liu, Lunjie; Kochman, Michal A.; Xu, Yongjie; Zwijnenburg, Martijn A.; Cooper, Andrew I.; Sprick, Reiner Sebastian. Synthetic Route of C5H3Br2N And the article was included in Journal of Materials Chemistry A: Materials for Energy and Sustainability in 2021. The article conveys some information:

Conjugated organic polymers have shown potential as photocatalysts for hydrogen production by water splitting. Taking advantage of a high throughput screening workflow, two series of acetylene-linked co-polymers were prepared and studied for their potential as photocatalysts for sacrificial hydrogen production from water. It was found that a triethynylbenzene-based polymer with a dibenzo[b,d]thiophene sulfone linker (TE11) had the highest performance in terms of hydrogen evolution rate under visible illumination in the presence of a sacrificial hole-scavenger. Synthetically elaborating the triethynylbenzene linker in TE11 by changing the core and by introducing nitrogen, the resulting hydrogen evolution rate was further increased by a factor of nearly two. The experimental part of the paper was very detailed, including the reaction process of 2,5-Dibromopyridine(cas: 624-28-2Synthetic Route of C5H3Br2N)

2,5-Dibromopyridine(cas: 624-28-2) belongs to pyridine. Pyridine and its simple derivatives are stable and relatively unreactive liquids, with strong penetrating odours that are unpleasant.Synthetic Route of C5H3Br2N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Safety of 2-(Bromomethyl)pyridine hydrobromideIn 2017 ,《Pyridine-antipyrine appended indole derivative for selective recognition of Fe3+: Concentration dependent coloration》 appeared in Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy. The author of the article were Ta, Sabyasachi; Nandi, Sandip; Ghosh, Milan; Banerjee, Somenath; Das, Debasis. The article conveys some information:

Combination of pyridine, antipyrine and indole in a single mol. (L2) allows selective recognition of Fe3 + colorimetrically in CH3CN. The structure of L2 is confirmed from single crystal x-ray diffraction anal. The probe displays two different visible bands at 541 nm and 715 nm in the presence of Fe3 +, associated with two different colors, viz. green and pink-violet allowing determination of unknown Fe3 + concentration Removal of 2-picolyl group from indole N-center of L2 generates L3 that behaves similarly at low Fe3 + concentration (> 0 to 1.1 mM) but differently at higher Fe3 + concentration (> 1.1 mM), indicating involvement of pyridyl-N donor towards Fe3 +, and hence different coordination environment around Fe3 + at higher concentration In the experiment, the researchers used 2-(Bromomethyl)pyridine hydrobromide(cas: 31106-82-8Safety of 2-(Bromomethyl)pyridine hydrobromide)

2-(Bromomethyl)pyridine hydrobromide(cas: 31106-82-8) 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.Safety of 2-(Bromomethyl)pyridine hydrobromide

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2019,International journal of environmental research and public health included an article by Tlotleng, Nonhlanhla; Kootbodien, Tahira; Wilson, Kerry; Made, Felix; Mathee, Angela; Ntlebi, Vusi; Kgalamono, Spo; Mokone, Moses; Du Preez, Karen; Naicker, Nisha. Category: pyridine-derivatives. The article was titled 《Prevalence of Respiratory Health Symptoms among Landfill Waste Recyclers in the City of Johannesburg, South Africa.》. The information in the text is summarized as follows:

In developing countries, waste sorting and recycling have become a source of income for poorer communities. However, it can potentially pose significant health risks. This study aimed to determine the prevalence of acute respiratory symptoms and associated risk factors for respiratory health outcomes among waste recyclers. A cross-sectional study was conducted among 361 waste recyclers at two randomly selected landfill sites in Johannesburg. Convenience sampling was used to sample the waste recyclers. The prevalence of respiratory symptoms in the population was 58.5%. A persistent cough was the most common symptom reported (46.8%), followed by breathlessness (19.6%) and rapid breathing (15.8%). Approximately 66.4% of waste recyclers reported exposure to chemicals and 96.6% reported exposure to airborne dust. A multivariable logistic regression analysis showed that exposure to waste containing chemical residues (OR 1.80, 95% CI 1.01-3.22 p = 0.044) increased the odds of respiratory symptoms. There was a significant difference in respiratory symptoms in landfill sites 1 and 2 (OR 2.77, 95% CI 1.03-7.42 p = 0.042). Occupational health and safety awareness is important to minimize hazards faced by informal workers. In addition, providing waste recyclers with the correct protective clothing, such as respiratory masks, and training on basic hygiene practices, could reduce the risks associated with waste sorting. In the part of experimental materials, we found many familiar compounds, such as 2-(2-Hydroxyethyl)pyridine(cas: 103-74-2Category: pyridine-derivatives)

2-(2-Hydroxyethyl)pyridine(cas: 103-74-2) 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

《Crystal structure of 4,15-dimethyl-7,12-diazoniatricyclo[10.4.0.02,7]-hexadeca-1(12),2,4,6,13,15-hexaene dibromide monohydrate》 was published in Acta Crystallographica, Section E: Crystallographic Communications in 2020. These research results belong to Behrman, Edward J.; Hansen, Alexandar L.; Yuan, Chunhua; Parkin, Sean. Synthetic Route of C12H12N2 The article mentions the following:

The title compound, C16H20N22+·2Br-·H2O (1) is a member of the class of compounds called viologens. Viologens are quaternary salts of dipyridyls and are especially useful as redox indicators as a result of their large neg. one-electron reduction potentials. Compound 1 consists of a dication composed of a pair of 4-methylpyridine rings mutually joined at the 2-position, with a dihedral angle between the pyridine rings of 62.35 (4)° . In addition, the rings are tethered via the pyridine nitrogen atoms by a tetramethylene bridge. Charge balance is provided by a pair of bromide anions, which are hydrogen bonded to a single water mol. [DO·cdtcdtBr = 3.3670 (15) and 3.3856 (15) Å]. The crystal structure of 1, details of an improved synthesis, and a full anal. of its NMR spectra are presented.4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6Synthetic Route of C12H12N2) was used in this study.

4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6) is used as a chemical Intermediate. It can be used for the determination of ferrous and cyanide compounds.Synthetic Route of C12H12N2 Furthermore, 4,4′-Dimethyl-2,2′-bipyridine is used in the synthesis of a series of o-phenanthroline-substituted ruthenium(II) complexes.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 1970,Journal of the Chemical Society [Section] B: Physical Organic included an article by Campbell, Arthur Derek; Chooi, S. Y.; Deady, L. W.; Shanks, R. A.. Safety of Methyl 5-methoxypicolinate. The article was titled 《Transmission of substituent effects of pyridines. I. Alkaline hydrolysis of some 3- and 4-substituted methyl pyridinecarboxylates》. The information in the text is summarized as follows:

The alk. hydrolysis of Me 5-(X-substituted)picolinates, Me 4-(X-substituted)picolinates, and Me 5-(X-substituted)nicotinates (X = NO2, Br, H, MeO, or Me2N) in methanol-water (85% wt/wt) is reported. In each series, the effect of the substituent and ring N are additive and the rates may be correlated with Hammett σm and σp values. In the experiment, the researchers used many compounds, for example, Methyl 5-methoxypicolinate(cas: 29681-39-8Safety of Methyl 5-methoxypicolinate)

Methyl 5-methoxypicolinate(cas: 29681-39-8) belongs to pyridine. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. As ligands, solvents, and catalysts they facilitate reactions; thus descriptions of these new ligands and their applications abound each year.Safety of Methyl 5-methoxypicolinate

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The author of 《An effective surface modification strategy with high reproducibility for simultaneously improving efficiency and stability of inverted MA-free perovskite solar cells》 were Zhu, Hongmei; Wu, Shaohang; Yao, Jiaxu; Chen, Rui; Pan, Ming; Chen, Weitao; Zhou, Jing; Zhang, Wenjun; Wang, Tao; Chen, Wei. And the article was published in Journal of Materials Chemistry A: Materials for Energy and Sustainability in 2019. Application of 1122-54-9 The author mentioned the following in the article:

Perovskite solar cells (PSCs) have become the front-running photovoltaic technol. and have triggered enormous research interest worldwide owing to their ultra-high solar-to-elec. power conversion efficiency and low fabrication costs, but their poor intrinsic stability issues still constitute the main obstacles that hinder their rapid commercialization. Herein, we demonstrate that, by carefully designing the modifier’s mol. structure, a facile, highly reproducible and scalable surface modification strategy can effectively enhance both the stability and efficiency of inverted PSCs. The most efficient modifier (2-acetylpyridine) can not only passivate the surface traps of the perovskite film but also enhance its stability against moisture by forming a hydrophobic capping layer on top. Accordingly, the efficiency of the inverted PSC has been improved from 16.75% to 20.05% for the best-performing one, which is, to our knowledge, among the highest values for inverted MA-free PSCs. More encouragingly, the stability of the modified devices can also be largely enhanced: the devices retained 95%, 90%, and 91% of their initial efficiencies after storage in the dark in ambient air for 2000 h, 85°C thermal aging for 500 h in the dark, and light soaking at 45°C for 500 h, resp. In the experiment, the researchers used 4-Acetylpyridine(cas: 1122-54-9Application of 1122-54-9)

4-Acetylpyridine(cas: 1122-54-9) belongs to pyridine. Pyridine derivatives lend themselves to many roles in the spirited field of supramolecular chemistry – whether as the ligand backbone of metal-organic polymers or presiding over the key electronic stations of nanodevices. In biochemistry, pyridine-containing cofactors are necessary nutrients on which our lives depend. Application of 1122-54-9

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Constructing antibacterial polymer nanocapsules based on pyridine quaternary ammonium salt》 was written by Zeng, Minghao; Xu, Jiayun; Luo, Quan; Hou, Chunxi; Qiao, Shanpeng; Fu, Shuang; Fan, Xiaotong; Liu, Junqiu. COA of Formula: C6H4N2This research focused ontrispyridyl triazine dibromoethane copolymer nanocapsule preparation antibacterial; Antibacterial; Cationic polymer nanocapsule; Pyridine quaternary ammonium salt. The article conveys some information:

Excessive use of antibiotics accelerates the development and spread of drug-resistant strains, which is a huge challenge for the field of medical health worldwide. Quaternary ammonium salt polymers are considered to be membrane-active bactericidal groups with vast potential to control bacterial infections and inhibit drug resistance. Herein, we report on the creative synthesis and characterization of novel antimicrobial polymer nanocapsules based on pyridine quaternary ammonium salt. The antimicrobial polymer nanocapsules were formed by reaction of C3 sym. rigid monomer 2,4,6-tris(4-pyridyl)-1,3,5-triazine (TPT) and a flexible linker 1,2-dibromoethane. The polymer nanocapsule was constructed as a cationic hollow sphere composed of a two-dimensional sheet whose main chain was formed by the pyridine quaternary ammonium salt, and a part of the bromide ion was adsorbed on the sphere. This hollow nanocapsule was characterized in detail by DLS, SEM, TEM, AFM, EDS and EA. When the cationic polymer nanocapsules are close to the Gram-neg. Escherichia coli, the neg. charged phospholipid mols. in the bacterial membrane are attracted to the cationic surface and lead to rupture of cells. SEM confirmed the breakage of Escherichia coli membranes. The min. inhibitory concentration was found to be 0.04 mg/mL, and the min. bactericidal concentration was 0.1 mg/mL. Our experiments demonstrated that the adsorption of neg. charged phospholipid mols. on the surface of the pyridine quaternary ammonium salt polymer can kill Gram-neg. bacteria without inserting quaternary ammonium salt hydrophobic groups into the cell membrane. In the experiment, the researchers used many compounds, for example, 4-Cyanopyridine(cas: 100-48-1COA of Formula: C6H4N2)

4-Cyanopyridine(cas: 100-48-1) belongs to pyridine. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Additionally, pyridine-based natural products continue to be discovered and studied for their properties and to understand their biosynthesis.COA of Formula: C6H4N2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Osmium sensitizer with enhanced spin-orbit coupling for panchromatic dye-sensitized solar cells》 was published in Journal of Materials Chemistry A: Materials for Energy and Sustainability in 2020. These research results belong to Juwita, Ratna; Lin, Jian-You; Lin, Shi-Jie; Liu, Yu-Chi; Wu, Tsung-Yu; Feng, Yu-Ming; Chen, Chia-Yuan; Gavin Tsai, Hui-Hsu; Wu, Chun-Geuy. COA of Formula: C12H12N2 The article mentions the following:

Low-lying triplet metal-to-ligand charge transfer (3MLCT) transitions of osmium complexes induced by spin-orbit coupling (SOC) are promising for extending the photocurrent response in dye-sensitized solar cells. In this study, a new osmium complex (CYC-33O) is presented, incorporating a 2-thiohexyl-3,4-ethylenedioxythiophene functionalized bipyridyl ancillary ligand to red-shift the absorption and enhance the absorbance of singlet and triplet metal-to-ligand charge transfer (1MLCT and 3MLCT) transitions. Time-dependent d. functional theory (TDDFT) calculations show that the reinforced 1MLCT and 3MLCT transitions of CYC-33O are mainly from osmium to the 4,4′,4′′-tricarboxy-2,2′:6′,2′′-terpyridine anchoring ligand, increasing the heterogeneous electron transfer between CYC-33O and TiO2. The device sensitized with CYC-33O exhibits panchromatic conversion beyond 1000 nm, yielding a photocurrent d. of 19.38 mA cm-2, which is much higher than those of the cells based on the ruthenium analog (CYC-33R) and model osmium complex (Os-3) sensitizers. In the part of experimental materials, we found many familiar compounds, such as 4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6COA of Formula: C12H12N2)

4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6) is used as a chemical Intermediate. It can be used for the determination of ferrous and cyanide compounds.COA of Formula: C12H12N2 Furthermore, 4,4′-Dimethyl-2,2′-bipyridine is used in the synthesis of a series of o-phenanthroline-substituted ruthenium(II) complexes.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem