An update on the compound challenge: C5H4N2O2

Name: Pyrazine-2-carboxylic acid. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Wang, GY; Sun, XW; Bai, J; Han, LM or concate me.

An article Preparation of Fe-C nanofiber composites by metal organic complex and potential application in supercapacitors WOS:000461168600035 published article about DOPED POROUS CARBON; OXYGEN REDUCTION REACTION; ELECTRODE MATERIAL; ASSISTED SYNTHESIS; PERFORMANCE; GRAPHENE; ANODE; POLYACRYLONITRILE; ELECTROCATALYSTS; NANOPARTICLES in [Wang, Guanyi; Sun, Xingwei; Bai, Jie; Han, Limin] Inner Mongolia Univ Technol, Chem Engn Coll, Hohhot 010051, Peoples R China in 2019, Cited 49. Name: Pyrazine-2-carboxylic acid. The Name is Pyrazine-2-carboxylic acid. Through research, I have a further understanding and discovery of 98-97-5

In this paper, high-capacity supercapacitor material (Fe-Nx/CNFs) synthesized by electrospinning a metal complex in PAN/DMF solution with different temperatures was presented. Moreover, nitrogen doping (N-doping in short) has been used to tailor the properties of carbon nanofibers and rendered its potential use for capacitor as an effective way. The structural and morphological properties of the Fe-Nx/CNFs were fully characterized and the carbonation temperature of the Fe-Nx/CNFs precursor was optimized. Compared with the pure carbon nanofiber, the annealing temperature of optimized Fe-Nx/CNFs composites electrode material was 550 degrees C. Fabricating the binder-free iron-based electrode exhibited a higher capacitance of 629Fg(-1) at the current density of 1Ag(-1) in 4molL(-1) aqueous KOH electrolyte. Meanwhile, a cycling stability of 97% capacitance retention after cycling 2500at 5Ag(-1) was maintained. This outstanding performance was attributed to the formation of the Fe-N bond and N-doped carbon nanofibers that effectively facilitates electronic transport. Therefore, carbon nanofibers, wherein nitrogen-doped metal (iron) center, exhibited high performance as supercapacitors.

Name: Pyrazine-2-carboxylic acid. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Wang, GY; Sun, XW; Bai, J; Han, LM or concate me.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Never Underestimate The Influence Of 98-97-5

Safety of Pyrazine-2-carboxylic acid. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Guro, K; Horikoshi, R; Nakamura, S; Mitomi, M; Oyama, K; Hirose, T; Sunazuka, T; Omura, S or concate me.

Safety of Pyrazine-2-carboxylic acid. In 2019 J PESTIC SCI published article about ACYL-COA; ASPERGILLUS-FUMIGATUS; CHEMICAL-MODIFICATION; STRUCTURE ELUCIDATION; INHIBITORS; POTENT; RESISTANCE; METABOLITE in [Guro, Kimihiko; Horikoshi, Ryo; Nakamura, Satoshi; Mitomi, Masaaki; Oyama, Kazuhiko] Meiji Seika Pharma Co Ltd, Agr & Vet Div, Agr & Vet Res Labs, Kohoku Ku, 760 Morooka Cho, Yokohama, Kanagawa, Japan; [Hirose, Tomoyasu; Sunazuka, Toshiaki; Omura, Satoshi] Kitasato Univ, Kitasato Inst Life Sci, Grad Sch Infect Control Sci, Tokyo, Japan in 2019, Cited 22. The Name is Pyrazine-2-carboxylic acid. Through research, I have a further understanding and discovery of 98-97-5.

Pyripyropene A (PP-A), a secondary metabolite produced by filamentous fungi, shows insecticidal activity against agricultural insect pests. Synthesized PP derivatives also show a narrow insecticidal spectrum but high insecticidal activities against such sucking pests. PP-A has a low eco-toxicological impact and satisfies a prerequisite for next-generation insecticides. We investigated the effects of conversion of the 3-pyridyl and a-pyrone rings to other rings, as well as the effects of esterification, dehydration, and oxidization at the C-13 position in natural PP analogues, on the insecticidal activity and spectrum. The conversions of the 3-pyridyl and alpha-pyrone rings markedly reduced the insecticidal activity with a minimal impact on the spectrum, indicative of an important role for these rings in insecticidal activity. Some derivatives with modified structures at the C-13 position showed a higher inhibitory effect on the motility of canine heartworms and mosquito vectors than did PP-A, suggesting their utility as filaria control drugs.

Safety of Pyrazine-2-carboxylic acid. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Guro, K; Horikoshi, R; Nakamura, S; Mitomi, M; Oyama, K; Hirose, T; Sunazuka, T; Omura, S or concate me.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Properties and Exciting Facts About C5H4N2O2

Recommanded Product: Pyrazine-2-carboxylic acid. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Kashid, BB; Ghanwat, AA; Khedkar, VM; Dongare, BB; Shaikh, MH; Deshpande, PP; Wakchaure, YB or concate me.

Recently I am researching about ONE-POT SYNTHESIS; 2-SUBSTITUTED BENZOTHIAZOLES; OXIDATIVE CYCLIZATION; CATALYST; EFFICIENT; 2-ARYLBENZOXAZOLES; BASES, Saw an article supported by the . Published in WILEY in HOBOKEN ,Authors: Kashid, BB; Ghanwat, AA; Khedkar, VM; Dongare, BB; Shaikh, MH; Deshpande, PP; Wakchaure, YB. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid. Recommanded Product: Pyrazine-2-carboxylic acid

A series of novel 2-substituted benzimidazole and benzoxazole derivatives as a potential antimicrobial and antioxidant agent were synthesized via coupling of N-methyl-o-phenylenediamine or 2-amino-phenol with aromatic aldehyde and acid in the presence of polyphosphoric acid as an efficient catalyst as well as solvent by conventional method in short reaction times with excellent yield. The newly synthesized benzimidazole and benzoxazole derivatives were evaluated for antimicrobial and antioxidant activity and exhibited excellent to good activities compared to the standard drugs. Furthermore, the theoretical predictions based on molecular docking against microbial DNA gyrase could provide an insight into the plausible mechanism of action and establish a link between the observed antimicrobial activity and the binding affinity shedding light on specific thermodynamic (bonded and nonbonded) interactions governing the activity. Furthermore, the synthesized compounds were analyzed for absorption, distribution, metabolism, and excretion properties and exhibited potential properties to build up as good oral drug candidates.

Recommanded Product: Pyrazine-2-carboxylic acid. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Kashid, BB; Ghanwat, AA; Khedkar, VM; Dongare, BB; Shaikh, MH; Deshpande, PP; Wakchaure, YB or concate me.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Chemical Properties and Facts of C5H4N2O2

Quality Control of Pyrazine-2-carboxylic acid. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Pakyapan, B; Kavukcu, SB; Sahin, ZS; Turkmen, H or concate me.

I found the field of Chemistry very interesting. Saw the article Synthesis and catalytic applications of Ru and Ir complexes containing N,O-chelating ligand published in 2020. Quality Control of Pyrazine-2-carboxylic acid, Reprint Addresses Turkmen, H (corresponding author), Univ Ege, Fac Sci, Dept Chem, TR-35100 Izmir, Turkey.. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid

A series of monometallic complexes (Ru1-3, Ir-1(-3)) which have N,O-chelating ligand (pyrazine-2carboxylate (1), pyridine-2-carboxylate (2), quinoline carboxylate(3) and bimetallic complexes (Ru-4,Ru-5, Ir-4(,5)) bridged by pyrazine-2,3- dicarboxylate (4) and imidazole-4,5-dicarboxylate(5) were synthesized and characterized by H-1-, C-13 NMR, FT-IR, and elemental analysis. The crystal structure of Ir-2 was determined by X-ray crystallography. The complexes (Ru1-5, Ir1-5) were applied to investigate the electronic and steric effect of ligand in their catalytic activities in transfer hydrogenation and alpha(alpha)-alkylation reaction of ketones with alcohols. The activities of iridium complexes (Ir1-5) were much more efficient than ruthenium complexes (Ru1-5). The highest activity for both reactions was observed for the complex (Ir2 ) with pyridine-2-carboxylate. The Ir hydride species was monitored for both reactions. (C) 2020 Elsevier B.V. All rights reserved.

Quality Control of Pyrazine-2-carboxylic acid. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Pakyapan, B; Kavukcu, SB; Sahin, ZS; Turkmen, H or concate me.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

When did you first realize you had a special interest and talent inPyrazine-2-carboxylic acid

About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Naef, R or concate me.. Computed Properties of C5H4N2O2

Naef, R in [Naef, Rudolf] Univ Basel, Dept Chem, CH-4003 Basel, Switzerland published Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at and around 298.15 K Based on Their True Molecular Volume in 2019, Cited 287. Computed Properties of C5H4N2O2. The Name is Pyrazine-2-carboxylic acid. Through research, I have a further understanding and discovery of 98-97-5.

A universally applicable method for the prediction of the isobaric heat capacities of the liquid and solid phase of molecules at 298.15 K is presented, derived from their true volume. The molecules’ true volume in A(3) is calculated on the basis of their geometry-optimized structure and the Van-der-Waals radii of their constituting atoms by means of a fast numerical algorithm. Good linear correlations of the true volume of a large number of compounds encompassing all classes and sizes with their experimental liquid and solid heat capacities over a large range have been found, although noticeably distorted by intermolecular hydrogen-bond effects. To account for these effects, the total amount of 1303 compounds with known experimental liquid heat capacities has been subdivided into three subsets consisting of 1102 hydroxy-group-free compounds, 164 monoalcohols/monoacids, and 36 polyalcohols/polyacids. The standard deviations for Cp(liq,298) were 20.7 J/mol/K for the OH-free compunds, 22.91 J/mol/K for the monoalcohols/monoacids and 16.03 J/mol/K for the polyols/polyacids. Analogously, 797 compounds with known solid heat capacities have been separated into a subset of 555 OH-free compounds, 123 monoalcohols/monoacids and 119 polyols/polyacids. The standard deviations for Cp(sol,298) were calculated to 23.14 J/mol/K for the first, 21.62 J/mol/K for the second, and 19.75 J/mol/K for the last subset. A discussion of structural and intermolecular effects influencing the heat capacities as well as of some special classes, in particular hydrocarbons, ionic liquids, siloxanes and metallocenes, has been given. In addition, the present method has successfully been extended to enable the prediction of the temperature dependence of the solid and liquid heat capacities in the range between 250 and 350 K.

About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Naef, R or concate me.. Computed Properties of C5H4N2O2

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Machine Learning in Chemistry about 98-97-5

About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Yao, H; Xie, SW; Ma, XQ; Liu, JK; Wu, HY; Lin, AJ; Yao, HQ; Li, DH; Xu, ST; Yang, DH; Chen, ZS; Xu, JY or concate me.. Recommanded Product: 98-97-5

In 2020 J MED CHEM published article about KAURENE-TYPE ORIDONIN; BIOLOGICAL EVALUATION; NATURAL-PRODUCTS; STRUCTURAL MODIFICATION; DITERPENOID ANALOGS; NITROGEN MUSTARDS; SPIROLACTONE-TYPE; ANTICANCER; DERIVATIVES; APOPTOSIS in [Yao, Hong; Xie, Shaowen; Ma, Xiaoqian; Liu, Junkai; Wu, Hongyu; Lin, Aijun; Yao, Hequan; Xu, Shengtao; Xu, Jinyi] China Pharmaceut Univ, State Key Lab Nat Med, Nanjing 210009, Peoples R China; [Yao, Hong; Xie, Shaowen; Ma, Xiaoqian; Liu, Junkai; Wu, Hongyu; Lin, Aijun; Yao, Hequan; Xu, Shengtao; Xu, Jinyi] China Pharmaceut Univ, Dept Med Chem, Nanjing 210009, Peoples R China; [Li, Dahong] Shenyang Pharmaceut Univ, Sch Tradit Chinese Mat Med, Key Lab Struct Based Drug Design & Discovery, Minist Educ, Shenyang 110016, Peoples R China; [Yang, Dong-Hua; Chen, Zhe-Sheng] St Johns Univ, Coll Pharm & Hlth Sci, Queens, NY 11439 USA in 2020, Cited 46. The Name is Pyrazine-2-carboxylic acid. Through research, I have a further understanding and discovery of 98-97-5. Recommanded Product: 98-97-5

Triple-negative breast cancer (TNBC) is one of the most highly invasive and metastatic breast cancers without safe and effective therapeutic drugs. The natural product oridonin is reported to be a potential anti-TNBC agent. However, its moderate activity and complex structure hampered its clinical application. In this study, the novel oridonin analogues were first identified by removal of multiple hydroxyl groups and structural simplification of oridonin. The representative analogue 20 exhibited potent anticancer effects. Further structural modification on 20 generated the most potent derivative 56, which possessed 120-fold more potent antiproliferative activity than oridonin in the TNBC cell line HCC1806. Importantly, compound 56 exhibited more potent anticancer activity than paclitaxel in TNBC xenograft nude mice. Moreover, 56 could attenuate the expression of MMP-2, MMP-9, p-FAK, and integrin beta 1 to inhibit TNBC cell metastasis. All results suggest that compound 56 may warrant further investigation as a promising candidate agent for the treatment of TNBC.

About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Yao, H; Xie, SW; Ma, XQ; Liu, JK; Wu, HY; Lin, AJ; Yao, HQ; Li, DH; Xu, ST; Yang, DH; Chen, ZS; Xu, JY or concate me.. Recommanded Product: 98-97-5

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Simple exploration of C5H4N2O2

About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Ma, JJ; Chen, SM; Bellotti, P; Guo, RY; Schafer, F; Heusler, A; Zhang, XL; Daniliuc, C; Brown, MK; Houk, KN; Glorius, F or concate me.. Computed Properties of C5H4N2O2

Computed Properties of C5H4N2O2. Authors Ma, JJ; Chen, SM; Bellotti, P; Guo, RY; Schafer, F; Heusler, A; Zhang, XL; Daniliuc, C; Brown, MK; Houk, KN; Glorius, F in AMER ASSOC ADVANCEMENT SCIENCE published article about in [Ma, Jiajia; Bellotti, Peter; Schafer, Felix; Heusler, Arne; Zhang, Xiaolong; Daniliuc, Constantin; Glorius, Frank] Westfalische Wilhelms Univ Munster, Organ Chem Inst, Corrensstr 40, D-48149 Munster, Germany; [Chen, Shuming; Houk, Kendall N.] Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA; [Guo, Renyu; Brown, M. Kevin] Indiana Univ, Dept Chem, Bloomington, IN 47405 USA in 2021, Cited 74. The Name is Pyrazine-2-carboxylic acid. Through research, I have a further understanding and discovery of 98-97-5

Dearomative cycloaddition reactions represent an ideal means of converting flat arenes into three-dimensional architectures of increasing interest in medicinal chemistry. Quinolines, isoquinolines, and quinazolines, despite containing latent diene and alkene subunits, are scarcely applied in cycloaddition reactions because of the inherent low reactivity of aromatic systems and selectivity challenges. Here, we disclose an energy transfer-mediated, highly regio- and diastereoselective intermolecular [4 + 2] dearomative cycloaddition reaction of these bicyclic azaarenes with a plethora of electronically diverse alkenes. This approach bypasses the general reactivity and selectivity issues, thereby providing various bridged polycycles that previously have been inaccessible or required elaborate synthetic efforts. Computational studies with density functional theory elucidate the mechanism and origins of the observed regio- and diastereoselectivities.

About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Ma, JJ; Chen, SM; Bellotti, P; Guo, RY; Schafer, F; Heusler, A; Zhang, XL; Daniliuc, C; Brown, MK; Houk, KN; Glorius, F or concate me.. Computed Properties of C5H4N2O2

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Awesome and Easy Science Experiments about Pyrazine-2-carboxylic acid

Product Details of 98-97-5. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Hu, JY; Ye, XF; Hao, S; Zhao, QR; Zhao, MQ; Wei, YW; Wu, ZY; Wang, N; Ji, XM or concate me.

Product Details of 98-97-5. Recently I am researching about CROSS-COUPLING REACTIONS; CARBOXYLIC-ACIDS; QUINOLINE; SITE; DERIVATIVES; CARBONYLATION; COMPLEXES; RECEPTOR, Saw an article supported by the Education Department of Henan Province [20 A210023]; Henan Agricultural University [30500567, 30500701]; Key Science and the Technology Program of Science and Technology Department of Henan Province [152102210058, 122102210129]. Published in WILEY-V C H VERLAG GMBH in WEINHEIM ,Authors: Hu, JY; Ye, XF; Hao, S; Zhao, QR; Zhao, MQ; Wei, YW; Wu, ZY; Wang, N; Ji, XM. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid

A highly efficient and simple procedure for the synthesis quinoline-3-carboxamides and their analogues via amidation reaction of quinoline-3-carboxylic acids with tetraalkylthiuram disulfides has been developed. The reaction proceeds efficiently under simple reaction conditions and features the generality of broad scope of substrates with good yields. This protocol provides a convenient procedure for the synthesis of various aza-heteroaromatic carboxamides, which is of pharmaceutical interest.

Product Details of 98-97-5. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Hu, JY; Ye, XF; Hao, S; Zhao, QR; Zhao, MQ; Wei, YW; Wu, ZY; Wang, N; Ji, XM or concate me.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

More research is needed about 98-97-5

Quality Control of Pyrazine-2-carboxylic acid. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Rehman, AU; Khan, MT; Liu, H; Wadood, A; Malik, SI; Chen, HF or concate me.

Authors Rehman, AU; Khan, MT; Liu, H; Wadood, A; Malik, SI; Chen, HF in AMER CHEMICAL SOC published article about MOLECULAR-DYNAMICS; SHAPE COMPLEMENTARITY; BINDING; DOCKING; SYSTEM; IDENTIFICATION; TRANSLATION; CONSTRAINTS; MUTATION; INSIGHT in [Rehman, Ashfaq Ur; Liu, Hao; Chen, Hai-Feng] Shanghai Jiao Tong Univ, Sch Life Sci & Biotechnol, Natl Expt Teaching Ctr Life Sci & Biotechnol, State Key Lab Microbial Metab,Dept Bioinformat &, Shanghai 200240, Peoples R China; [Chen, Hai-Feng] Shanghai Ctr Bioinformat Technol, Shanghai 200235, Peoples R China; [Khan, Muhammad Tahir; Malik, Shaukat Iqbal] Capital Univ Sci & Technol, Dept Bioinformat & Biosci, Islamabad 44000, Pakistan; [Rehman, Ashfaq Ur; Wadood, Abdul] Abdul Wali Khan Univ Marden, Dept Biotechnol, Mardan 23200, Pakistan in 2019, Cited 62. Quality Control of Pyrazine-2-carboxylic acid. The Name is Pyrazine-2-carboxylic acid. Through research, I have a further understanding and discovery of 98-97-5

Pyrazinamide (PZA) is an essential first line antitubercular drug, which plays a crucial role in tuberculosis treatment. The PZA, which is considered as a pro-drug needs an enzyme of mycobacterial pyrazinamidase (PZase) for its conversion into an active form pyrazinoic acid. Further, this active form of PZA inhibits the ribosomal proteins Si, which facilitates the transfer-mRNA complex formation throughout the translation. The spontaneous mutations in RpsA have been found to be associated with PZA drug resistance. However, the drug resistance mechanism is still unclear. Furthermore, there is no such information available about the structural dynamics of RpsA protein because of mutations that confer Pyrazinoic acid resistance. Moreover, a total of 18 clinical PZA-resistant isolates were investigated and found to be pncA(WT), which allowed exploration of the resistance mechanism of RpsA in the mutated state. Samples were repeated for the drug susceptibility testing followed by RpsA gene sequencing. A total of 11 clinical isolates harbored a total of 15 mutations. Almost half of the total strains (7/15) were observed to be in the conserved region of RpsA and known as Mycobacterium tuberculosis C-terminal domain. In the current study, (2/7) mutation T370P (mutant 1) and W403G (mutant 2) were explored to ensure the RpsA resistance mechanism through essential dynamics simulation. The essential dynamics study results revealed that the distal loop mutations drastically altered the conformation of RpsA both in the absence () and presence (+) of pyrazinoic acid drug for two reasons: (1) dramatic alteration or reduction in the binding pattern of pyrazinoic acid with active site residues observed and (2) a clear image of the opening and closing switching mechanism was seen upon the distal site mutation on nearby 3(10)-helixes beside the pyrazinoic acid binding site. This switch was found to consistently remain closed only in wild type systems, while it was open in the mutant systems. We called such distance impact an allosteric effect. The overall mechanistic investigations will provide useful information behind drug resistance for better understanding to manage tuberculosis.

Quality Control of Pyrazine-2-carboxylic acid. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Rehman, AU; Khan, MT; Liu, H; Wadood, A; Malik, SI; Chen, HF or concate me.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A new application aboutPyrazine-2-carboxylic acid

About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Lv, LN; Chen, BH; Liu, J; Chen, J; Xu, C; Yang, YQ or concate me.. Category: Pyrazines

Recently I am researching about AQUEOUS-SOLUTION; EQUILIBRIUM-CONSTANTS; CARBOXYLIC-ACIDS; URANIUM(VI); CRYSTAL; ION; CHEMISTRY; LIGAND, Saw an article supported by the National Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [11675156, 91326110, 21790372, 21822606]. Published in ROYAL SOC CHEMISTRY in CAMBRIDGE ,Authors: Lv, LN; Chen, BH; Liu, J; Chen, J; Xu, C; Yang, YQ. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid. Category: Pyrazines

Complexation of U(vi) with pyridazine-3-carboxylate (PDZ) and pyrazine-2-carboxylate (PAZ) was studied by spectrophotometry, potentiometry and microcalorimetry in 1.0 mol dm(-3) NaClO4. Three complexes, [UO2L](+), UO2L2(aq) and [UO2L3](-), were identified and their stability constants (log) and the corresponding formation enthalpies were determined. The thermodynamic parameters indicate that the formation of the three complexes is endothermic and driven exclusively by entropy. H-1 and C-13-NMR data provide insight into the coordination modes of the complexes which corroborate with the thermodynamic data. Ligands chelate to U(vi) via (2)(N,O) coordination mode in complexes [UO2L](+) and UO2L2(aq). The crystal structures of four U(vi) complexes, [(UO2)(PAZ)(2)(H2O)]H2O(i), [(UO2)(PDZ)(2)(H2O)](ii), [(UO2)(PDZ)(3)Na2ClO4]2H(2)O(iii), and [(UO2)(2)(PDZ)(4)(H2O)(2)]2H(2)O(iv), were determined by single-crystal X-ray diffraction and compared with the U(vi) complex with picolinate (PA) (CH6N3)[UO2(PA)(3)] in the literature. The structure data suggest that the carboxylates coordinate with uranium in O?C-O-U mode. The strengths of the U-O-C-C-N chelate cycles in the U(vi)/L complexes decrease with the trend of PA > PDZ > PAZ, which is in great agreement with the trend of thermodynamic parameters in aqueous solutions. It is interesting that in compound II two PDZ molecules coordinate with U(vi) in cis-planar positions via (2)(N,O) mode, but in other metal complexes of the three ligands having the same (2)(N,O) coordination mode the two ligand molecules are all in trans-arrangement. In the dimeric complex IV, one ligand coordinate with U(vi) in (2)(N,O) mode, while the other does it in (2)-L-(2)(O:O) mode respectively.

About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Lv, LN; Chen, BH; Liu, J; Chen, J; Xu, C; Yang, YQ or concate me.. Category: Pyrazines

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem