Month: October 2022

《Chromogenic hydrazide Schiff base reagent: Spectrophotometric determination of CN- ion》 was published in Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy in 2020. These research results belong to Dey, Sunanda; Sen, Chandana; Sinha, Chittaranjan. Name: Picolinic acid The article mentions the following:

A Schiff base reagent, Picolinohydrazide-naphthol (HL), was used for trace level detection of toxic CN- selectively in presence of eighteen other anions (SCN-, OCN-, S2O2-3, HPO2-4, H2PO-4, I-, ClO-4, HSO-4, SO2-4, AsO3-4, NO-2, AsO-2, Cl-, F-, HF-2, NO-3, Br-, N-3) by visual color change, colorless to yellow, in DMSO/H2O (9:1, volume/volume) at pH, 7.2 (HEPES buffer) medium. The sensitivity of the probe shows that the limit of detection (LOD) is 7.08μM. The probable mechanism for the sensing behavior involves the deprotonation of naphthol-OH by CN- that was authenticated by 1H NMR titration and Mass spectra. The composition (1:1 mol ratio) is supported by Job’s plot and binding constant (Ka, 1.5 × 104 M-1) is reported by Benesi-Hildebrand plot. Also, a simple paper strip device is fabricated for the determination of CN- ion in water. DFT computation is carried out to explain the electronic spectral feature of the sensor.Picolinic acid(cas: 98-98-6Name: Picolinic acid) was used in this study.

Picolinic acid(cas: 98-98-6) is used in the preparation of 2-Aminodihydro[1,3]thiazines as BACE 2 inhibitors and their preparation and use in the treatment of diabetes.Name: Picolinic acid

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2022,Fischer, Kim; Krahmer, Jan; Tuczek, Felix published an article in Zeitschrift fuer Naturforschung, B: A Journal of Chemical Sciences. The title of the article was 《Chemically and Light-Driven Coordination-Induced Spin State Switching (CISSS) of a nonheme-iron complex》.Synthetic Route of C12H13N3 The author mentioned the following in the article:

The new Fe(II) complex [Fe(trident)(bmik)](ClO4)2 (1) (trident = bis(2-pyridylmethyl)benzylamine and bmik = bis(1-methylimidazole)ketone) exhibits a change of magnetic moment in dichloromethane (DCM) solution upon addition of pyridine which is attributed to the Coordination-Induced Spin State Switching effect (CISSS). By attaching a photoisomerizable azopyridine sidegroup to the tridentate ligand the complex [Fe(azpy-trident)(bmik)](ClO4)2 (2; azpy-trident = [N,N-bis(2-pyridylmethyl)]-3-(3-pyridylazo)benzylamine) is obtained. As detected by Evans NMR spectroscopy, 2 reversibly changes its magnetic moment in homogeneous solution upon photoirradiation which is attributed to intermol. Light-Driven Coordination-Induced Spin State Switching (LD-CISSS). Further support for this interpretation is inferred from concentration-dependent Evans NMR measurements. In the experimental materials used by the author, we found Bis(pyridin-2-ylmethyl)amine(cas: 1539-42-0Synthetic Route of C12H13N3)

Bis(pyridin-2-ylmethyl)amine(cas: 1539-42-0) is a secondary amine with two picolyl substituents. As a tridentate ligand this compound provides three nitrogen donors that affords good selectivity for Zn2+ over biologically relevant metals such as Na+, K+, Mg2+ and Ca2+, and leaves coordination sites free for anion binding. Synthetic Route of C12H13N3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Simultaneous determination of phenazopyridine HCl and trimethoprim in presence of phenazopyridine HCl impurity by univariate and multivariate spectrophotometric methods – Quantification of phenazopyridine HCl impurity by univariate methods》 was written by Soudi, Aya T.; Hussein, Ola G.; Elzanfaly, Eman S.; Zaazaa, Hala E.; Abdelkawy, Mohamed. Synthetic Route of C5H7N3 And the article was included in Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy in 2020. The article conveys some information:

Three univariate and two multivariate spectrophotometric methods were developed and subsequently validated to determine phenazopyridine HCl (PHZ) and trimethoprim (TMP) in the presence of 2,6-Diaminopyridine (2,6-DAP). The first univariate method depends on direct determination of phenazopyridine by measuring its absorbance at 412 nm and performed in concentration range of 1.00-10.00μg/mL. Then the contribution of phenazopyridine is removed by dividing the mixture spectrum with PHZ divisor (5μg/mL) after that the constant is math. subtracted and finally the generated spectrum is multiplied with the PHZ divisor. These steps eliminate PHZ contribution and the recovered spectrum is that of TMP and 2,6-DAP only where different methods can be applied to determine TMP and 2,6-DAP through this binary mixture spectrum. The first method to determine both components depends on measuring both TMP and 2,6-DAP through their first derivative (1DD) spectra at 244.70 and 259.60 nm for TMP and 2,6-DAP, resp. with concentration ranges of 4.00-24.00μg/mL TMP and 4.00-26.00μg/mL 2,6-DAP. The second method depends on application of the isoabsorptive method which was used for TMP determination at its isoabsorptive point with 2,6-DAP at 242.64 nm with concentration range 1.00-20.00μg/mL for TMP. The developed univariate methods were successfully applied to determine PHZ, TMP and PHZ impurity (2,6-DAP). Two multivariate methods were applied for determination of PHZ and TMP in presence of 2,6-DAP namely, Principle Component Regression (PCR) and Partial Least Squares (PLS). The results of the two models show that simultaneous determination of PHZ and TMP in presence of PHZ impurity can be performed in the concentration ranges of 6.00-14.00μg/mL PHZ and 24.00-56.00μg/mL TMP. All the proposed methods were successfully applied to analyze PHZ and TMP in pharmaceutical formulations without interference from the dosage form additives and the results were statistically compared with the reported method.,. In the experimental materials used by the author, we found 2,6-Diaminopyridine(cas: 141-86-6Synthetic Route of C5H7N3)

2,6-Diaminopyridine(cas: 141-86-6) belongs to pyridine. Pyridine and its simple derivatives are stable and relatively unreactive liquids, with strong penetrating odours that are unpleasant.Synthetic Route of C5H7N3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2022,Bhalla, Parul; Tomer, Nisha; Bhagat, Pooja; Malhotra, Rajesh published an article in Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy. The title of the article was 《Chromone functionalized pyridine chemosensor for cupric ions detection》.Product Details of 141-86-6 The author mentioned the following in the article:

A new Schiff base 2-ethoxy-3-{[(6-{[(2-ethoxy-4-hydroxy-2H-chromen-3-yl)methylidene]amino}pyridine-2-yl)imino]methyl}-2H-chromen-4-ol (CD) was synthesized as a result of the condensation of 2,6-diaminopyridine and 3-formyl chromone in 1:2 M ratio and used for cupric ions detection and characterized through FTIR, HRMS and 1H NMR spectral techniques. The sensing capability of Schiff base for cupric ions as compared to other transition metal ions was examined by absorbance and emission studies. A considerable decrease in emission intensity appeared in Schiff base in the case of cupric ions while irrelevant changes were examined for the rest of the ions. The binding stoichiometry was obtained as 1:2 for CD: Cu2+ complex intended from the job′s plot which was confirmed through HRMS spectral technique. DFT calculations were carried for the confirmation of structural relationships and absorption-emission data. The Regression coefficient, Limit of detection, and Association constant were obtained as 98.7%, 1.2 x 10-6 M, and 3.26 x 104 M-1 resp. using Benesi-Hildebrand (B-H) equation. The sensing power of Schiff base CD to recognize cupric ions was unaltered by the addition of the rest of metal ions, which was authenticated through interference studies. Schiff base CD and its complex with cupric ions were found stable over an extensive time period as revealed by time-reliant studies. The data collected by pH studies revealed that the preferred pH range for detecting cupric ions by Schiff base CD was 6 to 11. The Schiff base was finally utilized for sensing cupric ions in a variety of spiked samples of water like canal water, tap water, groundwater, distilled water. In the experiment, the researchers used many compounds, for example, 2,6-Diaminopyridine(cas: 141-86-6Product Details of 141-86-6)

2,6-Diaminopyridine(cas: 141-86-6) belongs to pyridine. Pyridine and its simple derivatives are stable and relatively unreactive liquids, with strong penetrating odours that are unpleasant.Product Details of 141-86-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Crystal structures of a series of bis(acetylacetonato)oxovanadium(IV) complexes containing N-donor pyridyl ligands》 was written by Rood, Jeffrey A.; Reehl, Steven R.; Jacoby, Kaitlyn A.; Oliver, Allen. Safety of 4-CyanopyridineThis research focused onvanadium complex crystal structure crystallization; bidentate ligands; cis/trans isomers; coordination compound; crystal structure; vanadium(IV). The article conveys some information:

Crystal structures for a series of bis(acetylacetonato)oxovanadium(IV) complexes containing N-donor pyridyl ligands are reported, namely, bis(acetylacetonato-κ2O,O′)oxido(pyridine-κN)vanadium(IV), [V(C5H7O2)2O(C5H5N)], 1, bis(acetylacetonato-κ2O,O′)oxido(pyridine-4-carbonitrile-κN)vanadium(IV), [V(C5H7O2)2O(C6H4N2)], 2, and bis(acetylacetonato-κ2O,O′)(4-methoxypyridine-κN)oxidovanadium(IV), [V(C5H7O2)2O(C6H7NO)], 3, Compounds 1-3 have the formulas VO(C5H7O2)2L, where L = pyridine (1), 4-cyano-pyridine (2), and 4-methoxypyridine (3). Compound 1 was previously reported [Meicheng et al. (1984). Kexue Tongbao, 29, 759-764 and DaSilva, Spiazzi, Bortolotto & Burrow (2007). Acta Crystallogr., E63, m2422] and redetermined here at cryogenic temperatures Compounds 1 and 2 as pyridine and 4-cyanopyridine adducts, resp., crystallize as distorted octahedral structures with the oxo and pyridyl ligands trans to one another. A crystallog. twofold axis runs through the O-V-N bonds. Compound 3 containing a 4-methoxypyridine ligand crystallizes as a distorted octahedral structure with the oxo and pyridyl ligands cis to one other, removing the twofold symmetry seen in the other complexes. After reading the article, we found that the author used 4-Cyanopyridine(cas: 100-48-1Safety of 4-Cyanopyridine)

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.Safety of 4-Cyanopyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2018,Zeghouan, Ouahida; Dems, Mohamed AbdEsselem; Sellami, Seifeddine; Merazig, Hocine; Daran, Jean Claude published 《A strongly fluorescent NiII complex with 2-(2-hydroxyethyl)pyridine ligands: synthesis, characterization and theoretical analysis and comparison with a related polymeric Cu complex》.Acta Crystallographica, Section E: Crystallographic Communications published the findings.Category: pyridine-derivatives The information in the text is summarized as follows:

The synthesis and characterization of diaquabis 2-(2-hydroxyethyl)pyridine-κ2N,O nickel dinitrate, Ni C7H9NO2H2O2NO32, under ambient conditions is reported and compared with catena-poly bis 2-2-hydroxyethylpyridine-κ2N,O copper-μ-sulfato-κ2O:O’, CuC7H9NO2SO4n Zeghouan et al. 2016. Private communication refcode 1481676. CCDC, Cambridge, England. In the two complexes, the 2-(2-hydroxyethyl)pyridine ligands coordinate the metal ions through the N atom of the pyridine ring and the O atom of the hydroxy group, creating a chelate ring. The NiII or CuII ion lies on an inversion center and exhibits a slightly distorted MO4N2 octahedral coordination geometry, build up by O and N atoms from two 2-(2-hydroxyethyl)pyridine ligands and two water mols. or two O atoms belonging to sulfate anions. The sulfate anion bridges the CuII ions, forming a polymeric chain. The photoluminescence properties of these complexes have been studied on as-synthesized samples and reveal that both compounds display a strong blue-light emission with maxima around 497 nm. From DFT/TDDFT studies, the blue emission appears to be derived from the ligand-to-metal charge-transfer (LMCT) excited state. In addition, the IR spectroscopic properties and thermogravimetric behaviors of both complexes have been investigated. 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

《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