Tag: 100-200

Towards Weakly Coordinating Anions with the Extremely Electron Withdrawing Perfluoropyridinoxy Ligand -OC₅F₄N was written by Riddlestone, Ian M.;Keller, Sarah;Kirschenmann, Florian;Schorpp, Marcel;Krossing, Ingo. And the article was included in European Journal of Inorganic Chemistry in 2019.Related Products of 700-16-3 The following contents are mentioned in the article:

The extreme electron withdrawing properties of the perfluoropyridinoxy ligand -OC₅F₄N were used for the preparation of new (weakly) coordinating borate and aluminate anions [E(OC₅F₄N)₄]^– (E = B or Al). These new anions are based on the potent parent Lewis acids E(OC₅F₄N)₃, which possess exceptionally high calculated F^– ion affinities (FIAs) of 500 and 587 kJ mol^-1 for E = B and Al, resp. For Al, this extreme Lewis acidity dominates the chem. and from mixtures of the neutral polymeric Lewis acid [Al(OC₅F₄N)₃]_n, the five- and six-coordinate complexes Al(OC₅F₄N)₃(OEt₂)₂ (1) and [Al(OC₅F₄N)₂(μ-OC₅F₄N)(NCMe)₂]₂ (2) were crystallized upon addition of ether or MeCN. The aluminate salts M[Al(OC₅F₄N)₄] (M = Li or K) were prepared from the reaction between the alc. 4-HO-C₅F₄N and either LiAlH₄ or K[AlEt₄], resp. The aluminate anion [Al(OC₅F₄N)₄]^– remains Lewis acidic coordinating small donor mols. forming [Al(OC₅F₄N)₄(L)]^– (L = THF or NMe₃) and even supports formation and structural characterization of the Al dianion containing salt [Na(OEt₂)₂][Na][Al(OC₅F₄N)₅] (8). The from NaBH₄ and 4-HO-C₅F₄N accessible borate salt Na[B(OC₅F₄N)₄] shows increased kinetic stability in comparison to the Al analog. This study involved multiple reactions and reactants, such as 2,3,4,5,6-Perfluoropyridine (cas: 700-16-3Related Products of 700-16-3).

2,3,4,5,6-Perfluoropyridine (cas: 700-16-3) 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). 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.Related Products of 700-16-3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

To Anion-π or not to Anion-π: The Case of Anion-Binding to Divalent Fluorinated Pyridines in the Gas Phase was written by Goeth, Melanie;Witte, Felix;Quennet, Marcel;Jungk, Phillip;Podolan, Gabriel;Lentz, Dieter;Hoffmann, Waldemar;Pagel, Kevin;Reissig, Hans-Ulrich;Paulus, Beate;Schalley, Christoph A.. And the article was included in Chemistry – A European Journal in 2018.SDS of cas: 700-16-3 The following contents are mentioned in the article:

A series of mono- and divalent fluorinated pyridine derivatives is investigated by electrospray ionization (tandem) mass spectrometry and quantum chem. calculations with respect to their capability to bind anions in the gas phase. The pyridine derivatives differ not only in valency, but also with regard to the degree of fluorination of the pyridine rings, the positions of the fluorine atoms, the rigidity of the spacers connecting the two pyridines in the divalent compounds, and the relative configuration. While the monovalent compounds did not form anion complexes, the divalent analogs exhibit anion binding even to weakly coordinating anions such as tetrafluoroborate. Three different tandem mass spectrometric experiments were applied to rank the gas-phase binding energies: (i) collision-induced dissociation (CID) experiments in a Fourier transform ion-cyclotron-resonance (FTICR) mass spectrometer on two different, simultaneously mass-selected complexes with different receptors, (ii) determination of the collision energy required to fragment 50% of the mass-selected complexes in an ESI-QToF mass spectrometer, and (iii) CID of heterodimers formed from two different, competing pyridine receptors and indigo carmine, a dianion with two identical binding sites. All three experiments result in consistent binding energy ranking. This ranking reveals surprising features, which are not in agreement with binding through anion-π interactions. D. functional theory (DFT) calculations comparing different potential binding modes provide evidence that the ranking can instead nicely be explained, when C-H···anion interactions with the spacers are invoked. These results are supported by gas-phase IR spectroscopy and ion mobility-mass spectrometry (IM-MS) on a selected set of chloride pyridine complexes. This study involved multiple reactions and reactants, such as 2,3,4,5,6-Perfluoropyridine (cas: 700-16-3SDS of cas: 700-16-3).

2,3,4,5,6-Perfluoropyridine (cas: 700-16-3) belongs to pyridine derivatives. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.SDS of cas: 700-16-3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Toward Taming the Chemical Reversibility of Perfluoropyridine through Molecular Design with Applications to Pre- and Postmodifiable Polymer Architectures was written by Houck, Matthew B.;Fuhrer, Timothy J.;Phelps, Cole R.;Brown, Loren C.;Iacono, Scott T.. And the article was included in Macromolecules (Washington, DC, United States) in 2021.Formula: C5F5N The following contents are mentioned in the article:

Polymer functionality greatly determines many of the key properties of these materials, such as glass-transition temperature, elec. and thermal conductivity, thermal stability, mech. strength, and processability. Despite the importance of polymer functionality in determining material properties, the synthesis of functional polymers, with well-defined mol. weights and compositions, can still present a significant challenge, with many of the methods related to pre- or postpolymn. modification lacking synthetic scope, or requiring harsh functionalization conditions or transition-metal coupling reactions to install the desired functionality. Perfluoroarom. systems are promising for the preparation of novel polymer architectures given that they can be readily functionalized using simple nucleophilic chemistries under very mild basic conditions. While promising, these systems have displayed some drawbacks. Previous work has shown that perfluoroaroms., such as perfluoropyridine, can demonstrate a high degree of chem. reversibility with heteroatom nucleophiles. If the synthetic potential of these systems is to be realized, then a strategy for the rational design of stable monomers must be developed. Herein, we report the design, synthesis, and characterization of a series of unexplored heteroatom-based ring-opening metathesis polymerization (ROMP)-active monomers containing a reactive perfluoropyridine pendent group, which can be used to readily prepare a wide variety of aryl ether-functionalized polymers, using both pre- and postpolymn. modification strategies. We also establish a direct connection between the dihedral angle of the monomer and its propensity to undergo reversible addition reactions, establishing functional criteria for the design of pre- and postmodifiable systems. This study involved multiple reactions and reactants, such as 2,3,4,5,6-Perfluoropyridine (cas: 700-16-3Formula: C5F5N).

2,3,4,5,6-Perfluoropyridine (cas: 700-16-3) 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. 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.Formula: C5F5N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Optically active amines. XIV. Circular dichroism of 1-(2-, 3-, and 4-pyridyl)ethylamine and some related compounds was written by Smith, Howard E.;Schaad, L. J.;Banks, R. Bruce;Wiant, Christopher J.;Jordan, Charles F.. And the article was included in Journal of the American Chemical Society in 1973.Reference of 40154-80-1 The following contents are mentioned in the article:

Resolution with tartaric acid gave (S)-(-)-1-(2-, 3-, and 4-pyridyl)ethylamine and (R)-(+)-1-(3-pyridyl)ethylamine (I). The uv (isotropic absorption) and CD spectra of (S)-(+)-N-salicylidene-1-(2-pyridyl)ethylamine and (S)-(+)-N-(5-bromosalicylidene)-1-(4-pyridyl)ethylamine were examined These are similar to those of (S)-(+)-N-salicylidene-α-phenylethylamine, indicating that the CD spectra of such Schiff base derivatives may also be used for the establishment of the absolute configurations of chiral pyridyl-substituted alkylamines. 1-(4-Pyridyl)ethylamine on storage forms N-[1-(4-pyridyl)ethylidene]-1-(4-pyridyl)ethylamine by light-catalyzed oxidative process. For this reason, the racemic and optically active amines were converted to their resp. dihydrochlorides. The uv spectrum of each amine in 0.1M KOHMeOH shows an absorption maximum near 260 nm flanked by shoulders near 255 and 265 nm. These extrema are assigned to the π → π* (1Lb) transition of the pyridyl chromophore. Corresponding to each of these uv extrema, a pos. maximum is found in the CD spectra of (S)-(-)-1-(2-pyridyl)ethylamine (II) and I. For (S)-(-)-1-(3-pyridyl)ethylamine (III), the corresponding CD maximum are neg. No CD maximum was found in the spectrum of (S)-(-)-1-(4-pyridyl)ethylamine (IV) from 240 to 300 nm. In each CD spectrum there is a maximum near 240 nm, neg. for I, II, and IV and pos. for III. No corresponding absorption maximum near 240 nm was detected in any of the uv spectra. A first-order perturbation treatment of the CD spectra indicates that the 2B2 state at 180 nm makes a significant contribution to the rotational strength of the longer wavelength transitions. The CD maximum at 260 nm is due to the 1B2 ← 1A1 (π → π*) transition; the 240 nm maximum to the elec. dipole forbidden 1A2 ← 1A1 (n → π*) transition; and the rotational strength of the allowed 1B1 ← 1A1 (n → π*) transition near 288 nm is too weak to give an observable CD maximum All CD maximum disappear when the pyridine N lone pair is protonated in strong acid. This study involved multiple reactions and reactants, such as (S)-1-(Pyridin-4-yl)ethanamine dihydrochloride (cas: 40154-80-1Reference of 40154-80-1).

(S)-1-(Pyridin-4-yl)ethanamine dihydrochloride (cas: 40154-80-1) 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. Reduced pyridines, namely tetrahydropyridines, dihydropyridines and piperidines, are found in numerous natural and synthetic compounds. The synthesis and reactivity of these compounds have often been driven by the fact many of these compounds have interesting and unique pharmacological properties. Reference of 40154-80-1

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

XAD-2-A useful alternative to Tenax TA for analysis of biogenic volatiles employing thermal desorption coupled with gas chromatography-mass spectrometry was written by Marcillo, Andrea;Jakimovska, Viktorija;Widdig, Anja;Birkemeyer, Claudia. And the article was included in Journal of Chromatography A in 2017.Application In Synthesis of 2,3,4,5,6-Perfluoropyridine The following contents are mentioned in the article:

Volatile organic compounds (VOCs) are commonly collected from gaseous samples by adsorption to materials such as the porous polymer Tenax TA. Adsorbed compounds are subsequently released from these materials by thermal desorption (TD) and separated then by gas chromatog. (GC) with flame ionization (FID) or mass spectrometry (MS) detection. Tenax TA is known to be particularly suitable for nonpolar to semipolar volatiles, however, many volatiles from environmental and biol. samples possess a rather polar character. Therefore, the authors tested if the polymer XAD-2, which so far is widely used to adsorb organic compounds from aqueous and organic solvents, could provide a broader coverage for (semi)polar VOCs during gas-phase sampling. Mixtures of volatile compounds covering a wide range of volatility (b.p. 20-256°) and different chem. classes were introduced by liquid spiking into sorbent tubes with one of the two porous polymers, Tenax TA or XAD-2, and analyzed by TD/GC-MS. At 1st, an internal standard mixture composed of 17 authentic standards was used to optimize desorption temperature with respect to sorbent degradation and loading time for calibration. Secondly, the authors tested the detectability of a complex standard mixture composed of 57 volatiles, most of them common constituents of the body odor of mammals. Also, the performance of XAD-2 compared with Tenax TA was assessed as limit of quantitation and linearity for the internal standard mixture and 33 compounds from the complex standard mixture Volatiles were analyzed in a range between 0.01-∼250 ng/tube depending on the compound and material. Lower limits of quantitation were 0.01-3 ng ± <25% relative standard deviation (R² > 0.9). The authors found different kinetics for compound adsorption with XAD-2, and a partially better sensitivity in comparison with Tenax TA. For these analytes, XAD-2 might be recommended as an alternative of Tenax TA for TD/GC-MS anal. This study involved multiple reactions and reactants, such as 2,3,4,5,6-Perfluoropyridine (cas: 700-16-3Application In Synthesis of 2,3,4,5,6-Perfluoropyridine).

2,3,4,5,6-Perfluoropyridine (cas: 700-16-3) belongs to pyridine derivatives. Pyridines are an important class of heterocycles and occur in polysubstituted forms in many naturally occurring biologically active compounds, drug molecules and chiral ligands. 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.Application In Synthesis of 2,3,4,5,6-Perfluoropyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Ligand versus Complex: C-F and C-H Bond Activation of Polyfluoroaromatics at a Cyclic (Alkyl)(Amino)Carbene was written by Paul, Ursula S. D.;Radius, Udo. And the article was included in Chemistry – A European Journal in 2017.Computed Properties of C5F5N The following contents are mentioned in the article:

C-F and C-H bond activation reactions of polyfluoroaroms. at the cyclic (alkyl)(amino)carbene (cAAC) cAAC^methyl (1) are reported. Studies on the C-F bond activation using the cAAC-stabilized nickel(0) complex [Ni(cAAC^methyl)₂] (2) have shown that 2 does not react with fluorinated arenes. However, these investigations led to the observation of C-F bond cleavage of perfluorinated arenes by the carbene ligand cAAC^methyl (1) itself. The reaction of 1 with C₆F₆, C₆F₅-C₆F₅, C₆F₅-CF₃, and C₅F₅N afforded the insertion products of cAAC into one of the C-F bonds of the substrate, i.e., the C-F bond activation products (cAAC^methyl)F(Ar^f) (Ar^f=C₆F₅ 4 a, C₆F₄-C₆F₅ 4 b, C₆F₄-CF₃ 4 c, C₅F₄N 4 d). These products decompose readily upon heating to 80 °C within a few hours in solution with formation of ionic iminium salts [(cAAC^methyl)(Ar^f)][X] 6 a-d or neutral alkenyl perfluoroaryl imine compounds 7 a-d. The compounds (cAAC^methyl)F(Ar^f) 4 a-d readily transfer fluoride, which has been exemplified by the fluoride transfer of all compounds using BF₃ etherate as fluoride acceptor. Fluoride transfer has also been achieved starting from (cAAC^methyl)F(C₆F₄-CF₃) (4 c) or (cAAC^methyl)F(C₅F₄N) (4 d) to other selected substrates such as trimethylchlorosilane, benzoyl chloride and tosyl chloride. Instead of C-F bond activation, insertion of the cAAC into the C-H bond was observed if 1 was treated with the partially fluorinated arenes C₆F₅H, 1,2,4,5-C₆F₄H₂, 1,3,5-C₆F₃H₃, and 1,3-C₆F₂H₄. The compounds (cAAC^methyl)H(Ar^f) (Ar^f=C₆F₅ 12 e, 2,3,5,6-C₆F₄H 12 f, 2,4,6-C₆F₃H₂ 12 g and 2,6-C₆F₂H₃ 12 h) have been isolated in good yields and have been characterized including X-ray anal. Fluorobenzene C₆FH₅ (pK_a ≈37), the least C-H acidic fluoroarene used in this study, does not react. In order to investigate the scope and limitations of this type of cAAC C-H bond activation reaction, cAAC^methyl (1) was treated with several other reagents of different C-H acidity such as imidazolium salts, imidazoles, esters, and trimethylphosphine. These investigations led to the isolation and characterization of the compounds [(cAAC^methyl)H(R₂Im^Me2)]X (13 a,b), (cAAC^methyl)H(Im^R2) (14 a-c), (cAAC^methyl)H(CH(COOCH₃)₂) (15 b) and (cAAC^methyl)H(CH₂-PMe₂) (16). Deprotonation of [(cAAC^methyl)H(Me₂Im^Me2)][BF₄] (13 a) at the cAAC carbon atom using KHMDS as a base led to isolation and structural characterization of the cAAC^methyl-NHC heterodimer (17). This study involved multiple reactions and reactants, such as 2,3,4,5,6-Perfluoropyridine (cas: 700-16-3Computed Properties of C5F5N).

2,3,4,5,6-Perfluoropyridine (cas: 700-16-3) 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. Reduced pyridines, namely tetrahydropyridines, dihydropyridines and piperidines, are found in numerous natural and synthetic compounds. The synthesis and reactivity of these compounds have often been driven by the fact many of these compounds have interesting and unique pharmacological properties. Computed Properties of C5F5N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

challenges of fast sampling of volatiles for thermal desorption gas chromatog. – mass spectrometry was written by Marcillo, Andrea;Weiss, Brigitte M.;Widdig, Anja;Birkemeyer, Claudia. And the article was included in Journal of Chromatography A in 2020.Electric Literature of C5F5N The following contents are mentioned in the article:

Fast active sampling of volatile organic compounds (VOCs) under field conditions still is a great challenge especially when the exposure time to the source of emissions is a restricting factor. Hence, to identify ideal conditions for such applications, we systematically compared fast active sampling of VOCs collected on two common adsorbents under two regimes: first, very low gas volumes (from 300 mL) sampled at nominal flow rate and, second, sampling at the maximal applicable flow rate (0.5 L/min) before loss of sorbent material was experienced. For XAD-2 and Tenax TA, efficient sorbents for on-site VOC-sampling followed by thermal desorption GC-MS, significant differences in the signal response of volatile compounds were related not only to the varied exptl. factors alone, but also to their interactions and to compound volatility. In the first regime, volatiles (∼0.004-3.13 mM) from Tenax TA gave the highest signal response only above 800 mL sampled gas volume while at low concentrations (∼0.004-0.12 mM), satisfactory recovery from XAD-2 required longer analyte-sorbent interaction. For the second regime, the relative recovery was severely impaired down to 73 ± 23%, n = 56 for Tenax TA and 72 ± 17%, n = 56 for XAD-2 at intermediate concentration, and 79 ± 11%, n = 84 for Tenax TA at high concentration compared to the relative recovery at standard flow rate. Neither Tenax TA nor XAD-2 provided a 100% total recovery (calculated using breakthrough values) for any of the evaluated compounds Finally, two-way and three-way interactions identified in a multi-variable model, explained not only the dependence of the signal response on different exptl. variables, but also their complex interplay affecting the recovery of the VOCs. In conclusion, we show for the first time that XAD-2, a material only recently introduced for the adsorption of volatiles from the gas phase, competes well with the standard material Tenax TA under conditions of fast sampling. Due to the similar absolute recovery with Tenax TA even at low concentration and with regard to the better detection limits, we consider XAD-2 the better choice for fast sampling of VOCs, particularly with low sample volumes at regular flow. For fast sampling with high flow rate, however, both sorbents might be selected only if the corresponding recovery loss can be accepted for the study. This study involved multiple reactions and reactants, such as 2,3,4,5,6-Perfluoropyridine (cas: 700-16-3Electric Literature of C5F5N).

2,3,4,5,6-Perfluoropyridine (cas: 700-16-3) 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. 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.Electric Literature of C5F5N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Matrix effects on hydrogen bonding and proton transfer in fluoropyridine – HCl complexes was written by Soares, Camilla;Ley, Anna R.;Zehner, Brittany C.;Treacy, Patrick W.;Phillips, James A.. And the article was included in Physical Chemistry Chemical Physics in 2022.SDS of cas: 700-16-3 The following contents are mentioned in the article:

We report an extensive computational and spectroscopic study of several fluoropyridine-HCl complexes, and the parent, pyridine-HCl system. Matrix-IR spectra for pentafluoropyridine-HCl, 2,6-difluororpyridine-HCl, and 3,5-difluororpyridine-HCl in solid neon exhibit shifts for the H-Cl stretching band that parallel the effects of fluorination on hydrogen-bond strength. Analogous spectral shifts observed across various host environments (solid neon, argon, and nitrogen) for pentafluoropyridine-HCl and 2,6-difluororpyridine-HCl convey a systematically varying degree of matrix stabilization on the hydrogen bonds in these complexes. An extended quantum-chem. study of pyridine-HCl and eight fluorinated analogs, including 2-, 3-, and 4-fluoropyridine-HCl, 2,6- and 3,5-difluororpyridine-HCl, 2,4,6- and 3,4,5-trifluropyridine-HCl, as well as pentafluoropyridine-HCl, was also performed. Equilibrium structures and binding energies for the gas-phase complexes illustrate two clear trends in how fluorine substitution affects hydrogen bond strength; increasing fluorination weakens these interactions, yet substitution at the 2- and 6-positions has the most pronounced effect. Bonding analyses for a select subset of these systems reveal shifts in electron d. that accompany hydrogen bonding, and most notably, the values of the electron d. at the N-H bond critical points among the stronger systems in this subset significantly exceed those typical for moderately strong hydrogen-bonds. We also explored the effects of dielec. media on the structural and bonding properties of these systems. For pyridine-HCl, 3-fluoropyridine-HCl, and 3,5-difluororpyridine-HCl, a transition to proton transfer-type structures is observed at ε-values of 1.2, 1.5, and 2.0, resp. This is signaled by key structural changes, as well as an increase in the neg. charge on the chorine, and dramatic shifts in topol. properties of the H-Cl and N-H bonds. In the case of pentafluoropyridine-HCl, and 2,6-difluororpyridine-HCl, we do not predict proton transfer in dielec. media up to ε = 20.0. However, there are clear indications that the media enhance hydrogen-bond strength, and moreover, these observations are completely consistent with the exptl. IR spectra. This study involved multiple reactions and reactants, such as 2,3,4,5,6-Perfluoropyridine (cas: 700-16-3SDS of cas: 700-16-3).

2,3,4,5,6-Perfluoropyridine (cas: 700-16-3) 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. 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.SDS of cas: 700-16-3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2019,Talanta included an article by Xu, Shaomei; Che, Songtian; Ma, Pinyi; Zhang, Fangmei; Xu, Longbin; Liu, Xin; Wang, Xinghua; Song, Daqian; Sun, Ying. Application of 1692-25-7. The article was titled 《One-step fabrication of boronic-acid-functionalized carbon dots for the detection of sialic acid》. The information in the text is summarized as follows:

Typically, sialic acids (SA) with a nine-carbon backbone are found at the glycan chain termini on the cell membranes, which play crucial roles in various physiol. and pathol. processes. The expression level of SA in the blood serum has been reported to correlate with various disease states among cancer. A novel approach for preparing fluorescent boronic-acid-modified carbon dots (C-dots) for the detection of SA was developed. The functionalized C-dots were synthesized by a facile, one-step hydrothermal method using 3-pyridineboronic acid as the sole carbon source. The added SA selectively recognized the C-dots, leading to the fluorescence quenching of the C-dots in a linear range of 80-4000 μM with a detection limit of 54 μM. The as-developed boronic-acid nanoprobe was successfully applied for the detection of SA in human serum samples with satisfactory results. In addition, this method afforded results within 4 min. Compared to other methods, this new proposed approach was simpler and exhibited excellent sensitivity and selectivity, demonstrating immense potential as an alternative for SA detection. In the experimental materials used by the author, we found Pyridin-3-ylboronic acid(cas: 1692-25-7Application of 1692-25-7)

Pyridin-3-ylboronic acid(cas: 1692-25-7) 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.Application of 1692-25-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2015,Gupta, G.; Iqbal, P.; Yin, F.; Liu, J.; Palmer, R. E.; Sharma, S.; Leung, K. Cham-Fai; Mendes, P. M. published 《Pt Diffusion Dynamics for the Formation Cr-Pt Core-Shell Nanoparticles》.Langmuir published the findings.HPLC of Formula: 13534-97-9 The information in the text is summarized as follows:

Layered core-shell bimetallic Cr-Pt nanoparticles were prepared by the formation and later reduction of an intermediate Pt-ion-containing supramol. complex onto preformed Cr nanoparticles. The resultant nanoparticles were characterized by x-ray diffraction anal., TEM, XPS, and aberration-corrected scanning TEM. The results are consistent with the presence of Pt diffusion during or after bimetallic nanoparticle formation, which resulted in a Pt/Cr-alloyed core and shell. The authors postulate that such Pt diffusion occurs by an elec.-field-assisted process according to Cabrera-Mott theory and that it originates from the low work function of the preformed oxygen-defective Cr nanoparticles and the rather large electron affinity of Pt. The experimental process involved the reaction of 6-Bromopyridin-3-amine(cas: 13534-97-9HPLC of Formula: 13534-97-9)

6-Bromopyridin-3-amine(cas: 13534-97-9) belongs to anime. The reaction of alkyl halides, R―X, where X is a halogen, or analogous reagents with ammonia (or amines) is useful with certain compounds. Not all alkyl halides are effective reagents; the reaction is sluggish with secondary alkyl groups and fails with tertiary ones. Its usefulness is largely confined to primary alkyl halides (those having two hydrogen atoms on the reacting site).HPLC of Formula: 13534-97-9

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem