Day: January 6, 2023

Analysis of volatile and semi-volatile alkaline compounds in tobacco leaf by using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry was written by Li, Hai-Feng;Zhong, Ke-Jun;Lu, Xin;Bai, Chang-Min;Huang, Jian-Guo;Lu, Hong-Liang;Ma, Chen-Fei;Zhu, Shu-Kui;Kong, Hong-Wei;Zhao, Ming-Yue;Xie, Jian-Ping;Niu, Sen;Xu, Guo-Wang. And the article was included in Huaxue Xuebao in 2006.HPLC of Formula: 644-98-4 This article mentions the following:

Comprehensive two-dimensional gas chromatog./time-of-flight mass spectrometry (GC × GC-TOFMS) has been applied for characterization of volatile and semi-volatile alk. compounds in oriental tobacco leaf. Simultaneous distillation extraction (SDE) was used as the sample extraction method. Two types of column set were compared, and appropriate GC × GC separation conditions were suggested. The results showed that the peaks detected by GC × GC method were far more than that by 1DGC. The separation behavior on 2D plot of different kinds of compounds was investigated. TOFMS library search combining structured chromatogram of GC × GC was used to identify the nitrogen-containing compounds in tobacco leaf. A total of 92 alk. compounds were tentatively identified. The results showed that GC × GC/TOFMS method is suitable for separation and identification of complex system. In the experiment, the researchers used many compounds, for example, 2-Isopropylpyridine (cas: 644-98-4HPLC of Formula: 644-98-4).

2-Isopropylpyridine (cas: 644-98-4) belongs to pyridine derivatives. In contrast to benzene, Pyridine’s electron density is not evenly distributed over the ring, reflecting the negative inductive effect of the nitrogen atom. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.HPLC of Formula: 644-98-4

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Triple Passivation Approach to Laminate Perovskite Layers for Augmented UV and Ambient Stable Photovoltaics was written by Garai, Rabindranath;Gupta, Ritesh Kant;Choudhury, Anwesha;Iyer, Parameswar Krishnan. And the article was included in ACS Applied Energy Materials in 2022.Recommanded Product: 91-02-1 This article mentions the following:

The instability of the perovskite solar cells (PSCs) toward UV irradiation and moisture is a limiting factor in terms of commercialization even after achieving excellent power conversion efficiencies (PCEs). Herein, an advanced triple passivation technique has been strategically designed and demonstrated utilizing UV-absorbing 2-benzoylpyridine (BP) mols. as a passivation additive to laminate perovskites and improve PSC stability. Double layers of BP were coated on both sides of the perovskite layer, and the mol. was also incorporated into the precursor solution This strategy significantly improved the perovskite crystallinity and film quality, lowered the recombination, and enhanced the carrier transport in the PSC. The triple-passivated device exhibited a high PCE of 20.46% with almost negligible hysteresis. Further, passivated large-area (2.5 cm²) devices were also fabricated that demonstrated a PCE of 18.61%. Moreover, the triple passivation approach exhibited impressive UV and ambient stability because it can effectively shield the perovskite layer from UV illumination and moisture. In the experiment, the researchers used many compounds, for example, Phenyl(pyridin-2-yl)methanone (cas: 91-02-1Recommanded Product: 91-02-1).

Phenyl(pyridin-2-yl)methanone (cas: 91-02-1) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Recommanded Product: 91-02-1

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

{[Cd(bpo)(SCN)₂]·CH₃CN}_n: A Novel Three-Dimensional (3D) Noninterpenetrated Channel-Like Open Framework with Porous Properties was written by Du, Miao;Chen, Shen-Tan;Bu, Xian-He. And the article was included in Crystal Growth & Design in 2002.Reference of 15420-02-7 This article mentions the following:

Reaction of CdCl₂·0.5H₂O with 2,5-bis(4-pyridyl)-1,3,4-oxodiazole (bpo) and NH₄SCN in a 1:1:2 molar ratio under MeCN-H₂O medium afforded a novel neutral three-dimensional (3D) coordination polymer {[Cd(bpo)(SCN)₂]·MeCN}_n (1) [monoclinic, space group P2₁/c, a 7.680(2), b 10.029(3), c 25.786(7) Å, β 93.779(5)°, Z = 4]. The crystal structure reveals that 1 has a 3-dimensional noninterpenetrating open framework with guest MeCN mols. in the cavities, in which the Cd^II centers (with CdN₄S₂ octahedral geometry) are bridged by the bpo mols. and SCN^– groups. It is interesting that the two-dimensional sheet in this 3-dimensional network consists of 16-membered [Cd₄(μ-SCN-N,S)₄] rings, and the bpo mols. extend these layers to a 3-dimensional structure, which is further stabilized by C-H…N H-bonding and strong π-π-stacking interactions. TGA and x-ray powder diffraction technique measurements illustrate that the framework of 1 is retained upon removal of the uncoordinated guest MeCN mols., indicating that 1 might be used to generate microporous material. In the experiment, the researchers used many compounds, for example, 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7Reference of 15420-02-7).

2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7) 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. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Reference of 15420-02-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Configurationally Stable Biaryl Analogues of 4-(Dimethylamino)pyridine: A Novel Class of Chiral Nucleophilic Catalysts was written by Spivey, Alan C.;Fekner, Tomasz;Spey, Sharon E.;Adams, Harry. And the article was included in Journal of Organic Chemistry in 1999.Synthetic Route of C10H13BrN2O2 This article mentions the following:

A short synthetic approach toward a novel class of chiral nucleophilic catalysts, the dissymmetry of which stems from restricted rotation about an aryl-aryl bond, was developed. The key steps of the synthesis include preparation of a nucleophilic 1-methyl-2-pyrrolino[3,2-c]pyridine core by ortho-lithiation and creation of the biaryl axes via Suzuki cross-coupling reactions. Comparative HPLC studies of racemization for configurationally labile biaryls containing 1-methyl-2-pyrrolino[3,2-c]pyridine, 4-(dimethylamino)pyridine, and 4-(1-pyrrolidino)pyridine cores, resp., demonstrated that a pyrrolidino substituent ortho to the biaryl axis is optimal for slowing aryl-aryl rotation. Biaryls containing all 3 cores were shown to retain DMAP-like catalytic activity in the acylation of a hindered alc. 1-Methyl-7-(2-methyl- and -phenyl-1-naphthyl)-2-pyrrolino[3,2-c]pyridine, which are configurationally stable at ambient temperature, also were prepared via modification of configurationally labile derivatives These compounds in optically pure form should provide a useful starting point for studies on catalytic asym. acyl transfer using atropisomeric analogs of DMAP. In the experiment, the researchers used many compounds, for example, tert-Butyl (3-bromopyridin-4-yl)carbamate (cas: 257937-08-9Synthetic Route of C10H13BrN2O2).

tert-Butyl (3-bromopyridin-4-yl)carbamate (cas: 257937-08-9) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Synthetic Route of C10H13BrN2O2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Full-color-tunable phosphorescence of antimony-doped lead halide single crystal was written by Liao, Jin-Feng;Zhang, Zhipeng;Wang, Bingzhe;Tang, Zikang;Xing, Guichuan. And the article was included in npj Flexible Electronics in 2022.COA of Formula: C10H16BrN This article mentions the following:

Although multiple emissive phosphors are of great fundamental interest and practical importance, it is still challenging to achieve full-color tunable luminescence in a single-component material. Herein, we present an antimony-doped lead halide single crystal (C₁₀NH₂₂)₂PbBr₄: Sb³⁺ with widely tunable red/green/blue/white luminescence. Extrinsic Sb³⁺ dopants provide host another active sites to capture photo-generated excitons, thus triggering blue/red dual emission. Moreover, a reversible thermal-induced phase transition transforms blue/red emission into green/red dual emission. Both two phases exhibit intriguing excitation-wavelength dependent emission, affording a whole color gamut covering the red-green-blue (RGB) color triangle on the CIE 1931 diagram. Exptl. and theor. calculation studies reveal two emitters work independently, which paves the way for the multimode optical control and promotes the development of multifunctional luminescent materials. In the experiment, the researchers used many compounds, for example, 1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6COA of Formula: C10H16BrN).

1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.COA of Formula: C10H16BrN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Oxidation of styrylpyridinium dyes by permanganate ion was written by Dash, Sukalyan;Mishra, Bijay K.. And the article was included in Bulletin of the Chemical Society of Japan in 1994.Synthetic Route of C10H16BrN This article mentions the following:

The oxidation of N-alkyl substituted styrylpyridinium bromides in both KMnO₄ and cetyltrimethylammonium permanganate (CTAP) results in the formation of both of the corresponding substituted benzaldehydes. The oxidation in aqueous medium is catalyzed by acid whereas in CHCl₃ the reaction proceeds under neutral conditions. However, the reaction proceeds through the same mechanism in both the media. The faster rate of oxidation in aqueous medium by KMnO₄ than that in CHCl₃ medium by CTAP is rationalized through a hydrophobic effect. The overall rate equation can be represented as rate = k[Substrate]^1.5[Oxidant]^-0.75 in aqueous medium and rate = k[Substrate]^0.5[Oxidant]^-1 in CHCl₃. From the substituent effect a transition state with low electron d. at the olefinic carbon is proposed. In the experiment, the researchers used many compounds, for example, 1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6Synthetic Route of C10H16BrN).

1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6) 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. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Pyridine groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Synthetic Route of C10H16BrN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthesis, Cycloaddition, and Cycloreversion Reactions of Mononuclear Titanocene-oxo Complexes was written by Nguyen, Trang T.;Kortman, Gregory D.;Hull, Kami L.. And the article was included in Organometallics in 2016.SDS of cas: 3718-65-8 This article mentions the following:

Titanocene-oxo complexes of the type Cp^x₂Ti=O(L) (Cp^x = pentamethylcyclopentadienyl; tetramethylcyclopentadienyl; L = pyridine or derivatives) are synthesized from the corresponding titanocene-ethylene complexes via oxidation with pyridine N-oxides or styrene oxide. These oxo complexes react with alkynes, nitriles, and α,β-unsaturated carbonyls to form titanacycles, which undergo exchange reactions with organic substrates or react with 4-dimethylaminopyridine to regenerate the titanocene-oxo. Mechanistic experiments support a dissociative mechanism in which the first step is rate-determining retrocycloaddn. followed by trapping of the reactive [Cp^x₂Ti=O] species. In the case of the retro-[4+2]-cycloaddition from dioxatitanacyclohexene complexes, a Hammett study gives ρ values of -1.18 and -1.04 for substituents on two different Ph rings on the metallacycles, suggesting pos. charge buildup and a slightly asynchronous cycloreversion in the rate-determining step. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8SDS of cas: 3718-65-8).

3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) belongs to pyridine derivatives. In contrast to benzene, Pyridine’s electron density is not evenly distributed over the ring, reflecting the negative inductive effect of the nitrogen atom. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. SDS of cas: 3718-65-8

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

High-Precision Automated Workflow for Urinary Untargeted Metabolomic Epidemiology was written by Meister, Isabel;Zhang, Pei;Sinha, Anirban;Skold, C. Magnus;Wheelock, Asa M.;Izumi, Takashi;Chaleckis, Romanas;Wheelock, Craig E.. And the article was included in Analytical Chemistry (Washington, DC, United States) in 2021.Electric Literature of C5H5NO This article mentions the following:

Urine is a noninvasive biofluid that is rich in polar metabolites and well suited for metabolomic epidemiol. However, because of individual variability in health and hydration status, the physiol. concentration of urine can differ >15-fold, which can pose major challenges in untargeted liquid chromatog.-mass spectrometry (LC-MS) metabolomics. Although numerous urine normalization methods have been implemented (e.g., creatinine, sp. gr.-SG), most are manual and, therefore, not practical for population-based studies. To address this issue, we developed a method to measure SG in 96-well-plates using a refractive index detector (RID), which exhibited accuracy within 85-115% and <3.4% precision. Bland-Altman statistics showed a mean deviation of -0.0001 SG units (limits of agreement: -0.0014 to 0.0011) relative to a hand-held refractometer. Using this RID-based SG normalization, we developed an automated LC-MS workflow for untargeted urinary metabolomics in a 96-well-plate format. The workflow uses pos. and neg. ionization HILIC chromatog. and acquires mass spectra in data-independent acquisition (DIA) mode at three collision energies. Five tech. internal standards (tISs) were used to monitor data quality in each method, all of which demonstrated raw coefficients of variation (CVs) < 10% in the quality controls (QCs) and < 20% in the samples for a small cohort (n = 87 urine samples, n = 22 QCs). Application in a large cohort (n = 842 urine samples, n = 248 QCs) demonstrated CV_QC < 5% and CV_samples < 16% for 4/5 tISs after signal drift correction by cubic spline regression. The workflow identified >540 urinary metabolites including endogenous and exogenous compounds This platform is suitable for performing urinary untargeted metabolomic epidemiol. and will be useful for applications in population-based mol. phenotyping. In the experiment, the researchers used many compounds, for example, Pyridin-4-ol (cas: 626-64-2Electric Literature of C5H5NO).

Pyridin-4-ol (cas: 626-64-2) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C–H in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.Electric Literature of C5H5NO

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthesis of 2-aminochromene derivatives from 1-(2-imino-2H-chromen-3-yl)pyridin-1-ium perchlorates and nitromethane in basic medium was written by Storozhenko, Olga A.;Yue, Xiaoyi;Festa, Alexey A.;Varlamov, Alexey A.;Voskressensky, Leonid G.. And the article was included in Chemistry of Heterocyclic Compounds (New York, NY, United States) in 2020.COA of Formula: C7H7ClN2 This article mentions the following:

Novel 2-amino-4-(nitromethylidene)chromenes were obtained as a result of the reaction of 1-(2-imino-2H-chromen-3-yl)pyridinium perchlorates and nitromethane by the action of DBU at reflux in trifluoroethanol. The starting 2-iminochromenes are readily accessible from the corresponding salicylic aldehydes and quaternary cyanomethyl pyridinium salts. The reaction is tolerant to substituents of different nature (alkyl, alkoxy, halogen); a limitation is the presence of strong electron-withdrawing substituents in the benzene ring of chromene. During the reaction, the products precipitate and can be isolated by filtration. In the experiment, the researchers used many compounds, for example, 1-(Cyanomethyl)pyridin-1-ium chloride (cas: 17281-59-3COA of Formula: C7H7ClN2).

1-(Cyanomethyl)pyridin-1-ium chloride (cas: 17281-59-3) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.COA of Formula: C7H7ClN2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Derivatives of pyridine and quinoline. LXXXVIII. Reactions of bromo derivatives of 2- and 3-ethoxypyridines when heated with hydrochloric acid was written by den Hertog, H. J.;de Bruyn, J.. And the article was included in Recueil des Travaux Chimiques des Pays-Bas et de la Belgique in 1951.Application of 13472-81-6 This article mentions the following:

Following abstract When a bromoethoxypyridine (0.01 mole in 30-40 ml. 25% aqueous HCl) in a sealed tube is heated 4 hrs. at 160° in a shaking furnace, the Br is replaced by Cl when the former is in the 2- or 6-position, and the EtO group is replaced by the OH group. Thus 6-bromo-2-ethoxypyridine (I) gives 6-chloro-2-hydroxypyridine (II), m. 128.5-9°, and 2-bromo-3-ethoxypyridine (III) gives 2-chloro-3-hydroxypyridine, m. 169-70°, plus the corresponding dihydroxypyridines. The 3,5-di-Cl derivative of I yields 3,5,6-trichloro-2-hydroxypyridine, m. 174-5°. When the Br is in the 3- or 5-position it is not substituted by the procedure given. Thus 5-bromo-3-ethoxypyridine yields 5-bromo-3-hydroxypyridine. But either 3- or 5-bromo-2-ethoxypyridine yields mixtures of 3,5-dibromo-2-hydroxypyridine and 2-hydroxypyridine. As a further example of the positional reactivity of the Br, 2,5,6-tri-bromo-3-ethoxypyridine, m. 86-7°, prepared by heating 3-bromo-5-ethoxypyridine with Br in a sealed tube at 100°, gave 5-bromo-2,6-dichloro-3-ethoxypyridine, m. 77-8° with aqueous HCl. The EtO group in this case remained intact. In the experiment, the researchers used many compounds, for example, 3,5-Dibromo-2-hydroxypyridine (cas: 13472-81-6Application of 13472-81-6).

3,5-Dibromo-2-hydroxypyridine (cas: 13472-81-6) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of −48.7 × 10−6 cm3·mol−1.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ·mol−1 in the liquid phase and 140.4 kJ·mol−1 in the gas phase. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Application of 13472-81-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem