Tag: 200-300

Quinoxaline-based poly(phenylenevinylene)s copolymers: structure and optical properties was written by Zhang, Li;Zhang, Qiu-yu;Zhang, He-peng;Guo, Fei-ge;Sun, Jiu-li. And the article was included in Gaofenzi Cailiao Kexue Yu Gongcheng in 2010.Category: pyrazines This article mentions the following:

Low band gap polymers are expected to improve the efficiency of polymer solar cells. Polymers with donor-acceptor repeating units can lead to a reduction of band gap. Two novel poly(phenylenevinylene)s (PPV) copolymers PPV-QL and PPV-BPh containing alternating Ph rings and quinoxaline units were synthesized and characterized by NMR, FT-IR. The UV-vis absorption spectra in solution/films were characterized. The geometries of the oligomers were optimized using semi-empirical AMI. Although an alternate donor-acceptor repeating units has been imparted, PPV-QL and PPV-BPh still reveal a similar optical band gap value compared to homopolymer PPV. And the absorption maximum of PPV-QL and PPV-BPh was evidently blue-shifted comparison with that of PPV. The similar optical band gap and evident blue shift compared to PPV are mainly due to the large steric hindrance induced by the quinoxaline units which lead to destroyed chain coplanar. In the experiment, the researchers used many compounds, for example, 5,8-Dibromoquinoxaline (cas: 148231-12-3Category: pyrazines).

5,8-Dibromoquinoxaline (cas: 148231-12-3) belongs to pyrazine derivatives. Pyrazine is a symmetrical molecule with point group D2h. Pyrazine is less basic than pyridine, pyridazine and pyrimidine. Pyrazines are chemical compounds (technically called “methoxypyrazines”) found in grape skin and stems that are responsible for many “green” flavors in wine. Levels of pyrazines are dependent on viticultural practices, climate, and grape variety.Category: pyrazines

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Degradation of Pharmaceuticals through Sequential Photon Absorption and Photoionization in Amiloride Derivatives was written by Jorner, Kjell;Rabten, Wangchuk;Slanina, Tomas;Proos Vedin, Nathalie;Sillen, Sara;Wu Ludvigsson, Jufang;Ottosson, Henrik;Norrby, Per-Ola. And the article was included in Cell Reports Physical Science in 2020.Related Products of 1458-01-1 This article mentions the following:

Herein, the photodegradation of analogs of amiloride, which are known to undergo photosubstitution in water was reported. Model compounds built on the same scaffold undergo clean photosubstitution also in alc. solvent, where a certain amount of photodehalogenation was normally expected. Available evidence points to a mechanism starting with photoexcitation followed by photoionization to give a radical cation intermediate. Subsequent substitution reaction with the protic solvent was assisted by a general base, possibly strengthened by the proximal solvated electron. Recombination with the solvated electron generates the observed product. Quantum chem. computations revealed that excited state antiaromaticity is relieved when an electron is ejected from the photoexcited mol. by the second photon. The mechanism indicated here could have wide applicability to photoinduced degradation of similar heteroaromatic compounds in the environment, as well as to a class of increasingly popular synthetic photoredox methods. In the experiment, the researchers used many compounds, for example, Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate (cas: 1458-01-1Related Products of 1458-01-1).

Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate (cas: 1458-01-1) belongs to pyrazine derivatives. Pyrazines are volatile compounds that are used in the cosmetic, food, flavor, and fragrance industries. Pyrazines undergo nearly all of the same reactions as pyrimidines, from nucleophilic substitution (SNAr) to palladium-catalyzed cross coupling reactions.Related Products of 1458-01-1

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Structurally diverse covalent triazine-based framework materials for photocatalytic hydrogen evolution from water was written by Meier, Christian B.;Clowes, Rob;Berardo, Enrico;Jelfs, Kim E.;Zwijnenburg, Martijn A.;Sprick, Reiner Sebastian;Cooper, Andrew I.. And the article was included in Chemistry of Materials in 2019.Electric Literature of C8H4Br2N2 This article mentions the following:

A structurally diverse family of 39 covalent triazine-based framework materials (CTFs) are synthesized by Suzuki-Miyaura polycondensation and tested as hydrogen evolution photocatalysts using a high-throughput workflow. The two best-performing CTFs are based on benzonitrile and dibenzo[b,d]thiophene sulfone linkers, resp., with catalytic activities that are among the highest for this material class. The activities of the different CTFs are rationalized in terms of four variables: the predicted electron affinity, the predicted ionization potential, the optical gap, and the dispersibility of the CTFs particles in solution, as measured by optical transmittance. The electron affinity and dispersibility in solution are found to be the best predictors of photocatalytic hydrogen evolution activity. In the experiment, the researchers used many compounds, for example, 5,8-Dibromoquinoxaline (cas: 148231-12-3Electric Literature of C8H4Br2N2).

5,8-Dibromoquinoxaline (cas: 148231-12-3) belongs to pyrazine derivatives. Pyrazine heterocycles and their benzo derivatives possess many interesting properties, including chemical reactivity profiles, and have diverse applications in total synthesis, medicine, chemical biology, materials, dyes, and imaging. Pyrazine heterocycles and their benzo derivatives possess many interesting properties, including chemical reactivity profiles, and have diverse applications in total synthesis, medicine, chemical biology, materials, dyes, and imaging.Electric Literature of C8H4Br2N2

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

The effect of acceptor structure on emission color tuning in organic semiconductors with D-π-A-π-D structures was written by Ledwon, Przemyslaw;Wiosna-Salyga, Gabriela;Chapran, Marian;Motyka, Radoslaw. And the article was included in Nanomaterials in 2019.Application of 148231-12-3 This article mentions the following:

A series of novel donor-acceptor D-π-A-π-D compounds were synthesized and characterized in order to determine the influence of different acceptor units on their properties. The introduction of acceptor moieties had a direct impact on the HOMO and LUMO energy levels. Fluorescence spectra of compounds can be changed by the choice of an appropriate acceptor and were shifted from the green to the near-IR part of spectra. Due to observed concentration induced emission quenching, the green exciplex type host was used to evaluate the potential of synthesized mols. as emitters in organic light emitting diodes (OLEDs). In the experiment, the researchers used many compounds, for example, 5,8-Dibromoquinoxaline (cas: 148231-12-3Application of 148231-12-3).

5,8-Dibromoquinoxaline (cas: 148231-12-3) belongs to pyrazine derivatives. Pyrazine heterocycles and their benzo derivatives possess many interesting properties, including chemical reactivity profiles, and have diverse applications in total synthesis, medicine, chemical biology, materials, dyes, and imaging. Substituted pyrazines have been found as subunits of multiple synthetically constructed therapeutic agents, as well as several natural products.Application of 148231-12-3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthesis, Properties, and Reactivity of Bis-BN Phenanthrenes: Stepwise Bromination of the Main Scaffold was written by Zi, Lingjian;Zhang, Jinyun;Li, Chenglong;Qu, Yi;Zhen, Bin;Liu, Xuguang;Zhang, Lei. And the article was included in Organic Letters in 2020.Electric Literature of C8H4Br2N2 This article mentions the following:

Two bis-BN phenanthrenes I (7, R² = H; 8, R²-R² = CH₂CH₂) have been synthesized. Their photophys. properties are different from those of the reported mono-BN phenanthrenes. Moreover, the stepwise bromination of bis-BN phenanthrene 8 gave a series of brominated bis-BN phenanthrenes, with all of the mono-, di-, tri-, and tetrabrominated bis-BN phenanthrenes being successfully isolated and characterized. In addition, preliminary results showed that mono- and dibrominated species can be further functionalized by cross-coupling reactions. In the experiment, the researchers used many compounds, for example, 5,8-Dibromoquinoxaline (cas: 148231-12-3Electric Literature of C8H4Br2N2).

5,8-Dibromoquinoxaline (cas: 148231-12-3) belongs to pyrazine derivatives. Pyrazinesare six-membered aromatic heterocyclic organic compounds with two nitrogen atoms at 1,4-positions. Pyrazine is a weaker base (pKb = 13.4) than pyridine (pKb = 8.8), pyrimidine (pKb = 12.7). Pyrazines are chemical compounds (technically called “methoxypyrazines”) found in grape skin and stems that are responsible for many “green” flavors in wine. Levels of pyrazines are dependent on viticultural practices, climate, and grape variety.Electric Literature of C8H4Br2N2

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Red-Light-Emitting System Based on Aggregation of Donor-Acceptor Derivatives in Polar Aqueous Media was written by Ishi-i, Tsutomu;Ikeda, Kei;Kichise, Yuki;Ogawa, Michiaki. And the article was included in Chemistry – An Asian Journal in 2012.Reference of 148231-12-3 This article mentions the following:

The authors have demonstrated that an efficient red-light-emitting system can be created in polar water media based on the aggregation of donor-acceptor dyes triphenylamine benzothiadiazole, triphenylamine benzoselenodiazole, and triphenylamine quinoxaline aggregates. The UV/Vis absorption and fluorescence spectra of the dyes were measured in a THF/water mixture, in which the concentration was kept at 1 × 10^-5 M and only the water fraction (volume%) was changed from 0% to 90%. The aggregation leads to the restriction of the solvation-induced nonradiative deactivation to recover and enhance the emission. In the experiment, the researchers used many compounds, for example, 5,8-Dibromoquinoxaline (cas: 148231-12-3Reference of 148231-12-3).

5,8-Dibromoquinoxaline (cas: 148231-12-3) belongs to pyrazine derivatives. Pyrazine is an N-heterocyclic moiety, and it can be easily prepared from ethylenediamine and 1,2-diketone, α-hydroxyketone, α-methyl ketone. A number of pyrazine-based derivatives were used as dyes or fluorescent probes.Reference of 148231-12-3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Proton, carbon-13, and nitrogen-15 nuclear magnetic resonance and CNDO/2 studies on the tautomerism and conformation of amiloride, a novel acylguanidine was written by Smith, Robert L.;Cochran, David W.;Gund, Peter;Cragoe, Edward J. Jr.. And the article was included in Journal of the American Chemical Society in 1979.COA of Formula: C6H7ClN4O2 This article mentions the following:

The favored ground-state structures were determined for the novel acylguanidine diuretic, amiloride (I), and its free base using natural-abundance ¹H, ¹³C, and ¹⁵N NMR techniques and CNDO/2 theor. calculations I existed primarily in the acylamino tautomer form as planar conformer F1, whereas the free base preferred the acylimino tautomer form as planar conformer A1 (and/or A4). The dynamic mechanism(s) for the exptl. observed rapid equilibrium of the terminal amino groups in I and the free base and, when N-substituted, their substituents were explored by the CNDO/2 method. Of the six possible pathways considered for effecting N-10-N-11 interconversion in the free base a novel mechanism involving a synchronous rotation around ϕ₂ and ϕ₃ was calculated to have the lowest barrier to interconversion. Exptl. verification of this novel mechanism was attempted, but not found, by preparation of an appropriate model, II and subsequent determination of the ΔG^ values (14.7-14.8 kcal/mol) for II and pyrazine analogs using the dynamic ¹³C NMR technique in Me₂SO-d₆-CD₃OI). The free base is likely to undergo N-10-N-11 interconversion via simple ϕ₃ rotation and/or ϕ₂ rotation plus inversion. Accordingly, I must equilibrate by a ϕ₃ rotation mechanism. In the experiment, the researchers used many compounds, for example, Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate (cas: 1458-01-1COA of Formula: C6H7ClN4O2).

Methyl 3,5-diamino-6-chloropyrazine-2-carboxylate (cas: 1458-01-1) belongs to pyrazine derivatives. Pyrazine derivatives have antitumor, antibiotic, anticonvulsant, antituberculous and diuretic effects as well as kinase, enzymatic and potent tubulin and FtsZ polymerization inhibitory activities. Pyrazine and a variety of alkylpyrazines are flavor and aroma compounds found in baked and roasted goods. Tetramethylpyrazine (also known as ligustrazine) is reported to scavenge superoxide anion and decrease nitric oxide production in human Granulocytes.COA of Formula: C6H7ClN4O2

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem