Lignin‐derived carbon with pyridine N‐B doping and a nanosandwich structure for high and stable lithium storage

Biomass‐derived carbon is a promising electrode material in energy storage devices.However,how to improve its low capacity and stability,and slow diffusion kinetics during lithium storage remains a challenge.In this research,we propose a“self‐assembly‐template”method to prepare B,N codoped porous carbon(BN‐C)with a nanosandwich structure and abundant pyridinic N‐B species.The nanosandwich structure can increase powder density and cycle stability by constructing a stable solid electrolyte interphase film,shortening the Li^(+)diffusion pathway,and accommodating volume expansion during repeated charging/discharging.The abundant pyridinic N‐B species can simultaneously promote the adsorption/desorption of Li^(+)/PF_(6)^(−)and reduce the diffusion barrier.The BN‐C electrode showed a high lithium‐ion storage capacity of above 1140 mAh g^(−1)at 0.05 A g^(−1)and superior stability(96.5%retained after 2000 cycles).Moreover,owing to the synergistic effect of the nanosandwich structure and pyridinic N‐B species,the assembled symmetrical BN‐C//BN‐C full cell shows a high energy density of 234.7Wh kg^(−1),high power density of 39.38 kW kg−1,and excellent cycling stability,superior to most of the other cells reported in the literature.As the density functional theory simulation demonstrated,pyridinic N‐B shows enhanced adsorption activity for Li^(+)and PF_(6)^(−),which promotes an increase in the capacity of the anode and cathode,respectively.Meanwhile,the relatively lower diffusion barrier of pyridinic N‐B promotes Li^(+)migration,resulting in good rate performance.Therefore,this study provides a new approach for the synergistic modulation of a nanostructure and an active site simultaneously to fabricate the carbon electrode material in energy storage devices.

Syntheses,structures,and properties of three coordination polymers based on 5⁃ethylpyridine⁃2,3⁃dicarboxylic acid and N⁃containing ligands

Three coordination polymers[Mn(epda)(2,2'⁃bipy)(H_(2)O)](1),[Mn(epda)(phen)](2),and[Co_(2)(epda)2(bpe)2(H_(2)O)_(4)]·5H_(2)O(3)(H2epda=5⁃ethyl⁃pyridine⁃2,3⁃dicarboxylic acid,2,2'⁃bipy=2,2'⁃bipyridine,phen=phenanthroline,bpe=1,2⁃bis(4⁃pyridyl)ethylene)were synthesized by solvothermal reactions and characterized by single⁃crystal X⁃ray diffraction,thermogravimetric analyses,IR spectroscopy and elemental analysis.1 displays a 1D chain struc⁃ture,and these chains are joined by O-H…O hydrogen bonding andπ⁃πstacking interactions to generate a 2D layer structure.2 displays a 2D layer structure,and adjacent layers are generated 3D architecture throughπ⁃πstacking interactions.3 displays a 1D chain structure,and adjacent chains are generated double layer structure through O-H…O hydrogen bonding.The fluorescent properties of 1 and 3 indicate that they can potentially be used as a luminescent sensor.1 was highly selective and sensitive towards o⁃nitrophenol through different detection mechanisms,however,3 was highly selective and sensitive towards 2,4,6⁃trinitrophenol.In addition,the magnetic behavior of 2 has also been investigated.CCDC:2172533,1,2355773,2,2355774,3.

Theoretical Investigation on the Stability and Reactivity of Imidazo [1,2-a] Pyridine N-Acylhydrazone Derivatives Using Density Functional Theory

The reactivity and stability of seventeen (17) imidazo [1,2-a]pyridine N-acylhydrazone derivatives were investigated using density functional theory at the B3LYP/6-31+ G (d, p) level. Analysis of the molecular electrostatic potential (MEP) and determination of the dual descriptor revealed that in most cases, the nitrogen atoms of the 6-πelectron conjugation, the oxygen, and the sulfur atom are nucleophilic site. Chemical reactivity of the compounds was assessed through analysis of frontier molecular orbitals (HOMO and LUMO), energy gap (Δℰ), chemical hardness (η), and the softness (S). Consequently, the compound 9e exhibited the lowest reactivity, least electron donating, and the highest stability. This comprehensive study offers valuable insights into the chemical behavior of these derivatives, crucial for further exploration and potential applications.

Encapsulation of Ru(II) Polypyridine Complexes for Tumor-Targeted Anticancer Therapy

Ru(II)polypyridine complexes have attracted much attention as anticancer agents because of their unique photophysical,photochemical,and biological properties.Despite their promising therapeutic profile,the vast majority of compounds are associated with poor water solubility and poor cancer selectivity.Among the different strategies employed to overcome these pharmacological limitations,many research efforts have been devoted to the physical or covalent encapsulation of the Ru(II)polypyridine complexes into nanoparticles.This article highlights recent developments in the design,preparation,and physicochemical properties of Ru(II)polypyridine complex-loaded nanoparticles for their potential application in anticancer therapy.

Three-component Reaction of Aromatic Aldehyde,Malononitrile and Aliphatic Amine Leading to Different Pyridine Derivatives

The three-component reaction of aromatic aldehyde,malononitrile and aliphatic amine in a mixed solvent of methanol and water exhibited very interesting molecular diversity and gave the derivatives of polysubstituted N-methyldihydropyridines,2-dialkylaminopyridines and 2-methoxypyridines as main products according to the structure of aliphatic amines used.

The Reactivity of 2,4,6-Tirphenylpyridinium Ylids

Triphenylpyridinium ylid 2, generated by the decarboxylation of betaine 1, were noted to react with acetyl chloride, chloroform or acetone to form addition-elimination product and proton extraction - carbanion addition products, respectively. The reaction with chloroform was determined as pseudo first order from kinetic experiments. The values of kobsd and t1/2 for decarboxylation at 20, 40 and 50C were calculated to be 4.6 x 10-4, 8.8 x 10-3, 2.8 x 10-2 min-1 and 1.5 x 103, 78, 24 minutes, respectively.

Rapid Microwave-accelerated Multi-step Synthesis of 2,6-di（naphthalene Thioureido Carbamino）Pyridine

A rapid and simple procedure for synthesis of 2,6-di（naphthalene thioureido carbamino）pyridine fluorescine anion acceptor by the reaction between pyridine-2,6-dicarbohydrazide obtained from 2,6-dimethylpyridine after three-step reaction and 1-napbthyl isothiocyanate is described, and all reactions could be carried out under microwave heating condition.

以NBS/Pyridine氧化体系合成芳基芳酰基偶氮化合物

以芳基芳酰肼类化合物为原料,NBS/Pyridine为氧化体系,在室温下将芳基芳酰肼类化合物氧化脱氢得芳基芳酰基偶氮化合物,收率80%～92%。产品的结构经元素分析、IR、1HNMR确证。

Synthesis of a new pyridine-containing diamine and related polyimide

A new kind of aromatic diamine monomer containing pyridine unit,2,6-bis[4-(4-aminophenoxy)phenoxy]pyridine(BAPP),was synthesized in three steps,using hydroquinone as starting material.A novel pyridine-containing polyimide was prepared from the resulting diamine BAPP with 4,4 -oxydiphthalic anhydride(ODPA) via a conventional two-step thermal imidization method.The resulting polyimide exhibits excellent solubility,film-forming capability and high thermal resistance.

The Synthesis of Pyridine 2,6-dicarboxylic Acid Using Microwave Irradiation

This research took 2,6-dimethylpyridine as raw materials under microwave irradiation to syntheses pyridine 2,6-dicarboxylic acid by adding oxidation potassium permanganate. However, there are lots of factors affecting the yield including the amount of potassium permanganate and sulfuric acid, reaction time, power, 2,6-dimethylpyridine dosage. We made the further research, using orthogonal experiment to find the optimal process conditions. Thus our research changed the synthesis process from a traditional method to a new type of microwave technology.

Effects of 2-[p-(Dimethylamino)Styrl] PyridineMethiodide on Slow Response Action Potentialand Slow lnward Current of Guinea PigPapillary Muscles

The effects of 2-[p-(Dimethylamino)styryl] pyridine methiodide(DSPM)on slow response action potential(SRAP)and slow inward current(Isi) of guinea pig papillary muscles were studied by intracellular microelectrodes and voltage clamp techniques.The APA and V_(max) of SRAP induced by high K￣+were decreased after 50 min of perfusion with DSPM solu- tion. Isi was suppressed from a peak value of8.8± 1.6μA to 5.7± 1.8μA, The results indicated that DSPM has a selective blocking effect on calcium channel.

Luminescence Properties of Europium and Terbium Complexes with Pyridine or Bipyridine Linked Oligothiophene Ligand

With an aim to develop novel luminescence materials, europium and terbium complexes of 2, 5-(2-thiophene)-pyridine (TPY), 5, 5′-bis(5-(2, 2′-bithiophene))-2, 5-pyridine (B2TPY) and 5, 5′-bis(5-(2, 2′-bithiophene))-2, 2′-bipyridine (B2TBPY) were synthesized, and their luminescence properties were studied. The complexes exhibited ligand-sensitized emission, which was typical of Eu(Ⅲ) and Tb(Ⅲ) ions. The excitation spectra of Eu(Ⅲ) and Tb(Ⅲ) complexes with TPY (or B2TPY or B2TBPY) show similar bands as these with the ligands. It suggests that, the excitation energy is absorbed by TPY or B2TPY or B2TBPY, the energy transfers from its excited single state to its triplet state, and finally transfers from the ligands to Eu(Ⅲ) and Tb(Ⅲ) ions. The luminescence of Eu(Ⅲ) and Tb(Ⅲ) ions in the TPY or B2TPY or B2TBPY complexes indicates that the metal ions are efficiently excited by the absorbed energy from excitation of the ligands.

Synthesis of 2,4-Diarylcyclooctenopyridines with One-pot Four-component Reactions

An efficient one-pot four-component reaction has been developed for the synthesis of 2,4-diarylcyclooctenopyridines, in moderate yields. This route is an effective modified two-step synthesis of Krohnke pyridine and involves a four-component tandem reaction of pyridinium bromide with aromatic aldehydes and cyclooctanone in a system of NHaOAc/HOAc under microwave irradiation.

New Method for Reducing 2，6－Pyridinedicarboxylic Acid Diethyl Ester to 2，6－Di（hydroxymethyl）pyridine

Reducing 2, 6-pyridinedicaboxylic acid diethyl ester to 2,6-di(hydroxymethyl)pyridine was carried out by using NaBH4/CaCl2 as reducing agent. It is an improved and efficient method. The yield is up to 91%.

Design, Synthesis and Cancer Cell Line Activities of Pyrazolo[3,4-<i>b</i>]pyridine Derivatives

Starting from 4,6-dimethyl-2-oxo-(1H)-3-pyridinecarbonitrile 1 and 3-aminopyrazolopyridine 4, a series of cyanopyri- dine derivatives 3a-i, Schiff bases 5a-f, urea and thiourea derivatives 6a-b, amide derivatives 7a-h, pyridopyra- zolopy-rimidine 8a-b and pyridopyrazolotriazine 10a-b were synthesized. Activities of eleven representative compounds were evaluated against A-549 (lung), HEPG2 (liver) and HCT-116 (colon) cancer cell lines. The findings revealed that some of the synthesized compounds showed remarkable anticancer activities, especially 8b which displayed the highest activity among the tested compounds with IC50 equal to 2.9, 2.6 and 2.3 μmol. In addition to synthesis and biological activities, we present discussion about the rationale of the design and activity of the potent compound 8b using struc- ture-based modeling tools.

Synthesis, Characterization and Crystal Structure of Cobalt(II) Complex of a Schiff Base Derived from Isoniazid and Pyridine-4-Carboxaldehyde

A new hydrogen bonded Cobalt(II) Schiff base complex,?N’-(pyridine-4-carboxaldehyde) isonicotinoylhydrazone Cobalt(II), has been synthesized from isoniazid and pyridine-4-carboxaldehyde and characterized by IR spectroscopy, 1H-NMR, elemental analysis, TGA and single crystal X-ray structure determination. X-ray crystal structure analysis shows an octahedral complex with a metal centre coordinated to two ligand molecules through the pyridine nitrogen atoms and four water molecules and containing two nitrate groups as counter ions. The complex crystallizes in the monoclinic crystal system and P2(1)/n space group. The unit cell dimensions are: a = 7.2108(4) &Aring;, b = 16.6020(9) &Aring;, c = 13.0389(6) &Aring;,α = 90°, β = 103.972(4)°, γ = 90°. The molecule is symmetrical about the cobalt centre as observed from the 1H-NMR and 13C-NMR and confirmed by the single crystal X-ray structure of the complex. Thermogravimetric analysis shows two steps decomposition of the complex to leave a metal oxide residue. The title compound is expected to be biologically active as one of the precursors (isoniazid) is a therapeutic agent with well-established clinical applications.

Synthesis, Reactions and Characterization of 1,1’-(1,4-Phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(ethan-1-one)

Reaction of 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile) (1) with methyl iodide afforded the 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-(methylthio)nicotinonitrile) (2). The reaction of 2 with hydrazine hydrate followed by diazotization reaction af-forded the 1,1’-(1,4-phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(e-than-1-one) (3) and 1,1’-(1,4-phenylenebis(3-(chlorodiazenyl)-6-methyl-1H-pyrazolo[3,4-b]-pyridine-4,5-diyl))bis(ethan-1-one) (4) respectively. On the other hand, reaction of 4 with malononitrile, 2-cyanoethanethioamide, ethyl acetoacetate, acetyl acetone, ethyl benzoylacetate, diethylmalonate, ethyl cyanoacetate and phenacylbromide aiming to build up pyrazolotriazine or pyrazole ring on the ring system of 4. Structures of all newly synthesized heterocyclic compounds in the present study were confirmed by considering the data of IR, 1H NMR, mass spectra as well as that of elemental analyses.

一个新的三维超分子配位聚合物[Ni(pyridine-2-carboxylate)2]n·2nH2O的水热合成及晶体结构

采用水热法合成了一个新的金属-有机配位聚合物[Ni(pyridine-2-carboxylate)2]n.2nH2O,对其进行元素分析、红外光谱和X射线单晶衍射测定.结构分析表明:该晶体属于三斜晶系,P-1空间群,晶胞参数a=5.1284(6)nm,b=7.6346(9)nm,c=9.2295(11)nm,α=74.902(2)°,β=84.347(2)°,γ=71.442(2)°,V=330.70(7)nm3,化学式为C12H12NiN2O6,Mr=338.95,Dc=1.702g/cm3,μ(Mo,Kα)=1.497mm-1,F(000)=174,Z=1,R=0.0333,wR=0.0384((I>2σ(I)).并且该配合物通过O—H…O和C—H…O氢键形成了三维超分子网状结构.

Synthesis,Crystal Structure and Antifungal Activity of 4-(5-((2,4-Dichlorobenzyl)thio)-4-phenyl-4H-1,2,4-triazol-3-yl)pyridine

The title compound 4-（5-（（2,4-dichlorobenzyl）thio）-4-phenyl-4H-1,2,4-triazol-3- yl）pyridine （C20HI4CI2N4S） was synthesized, and its structure was confirmed by 1H NMR, MS, elemental analyses and X-ray diffraction. It crystallizes in the monoclinic system, space group P21/c with a = 14.885（5）, b = 8.597（2）, c = 16.144（5）A,β= 114.505（4）°, V= 1879.8（10） A3, Z= 8 and R = 0.0320 for 3108 observed reflections with I 〉 2σ（I）. The preliminary biological test shows that the title compound has activities against Stemphylium lyeopersici （Enjoji） Yamamoto, Fusarium oxysporum, sp. cueumebrium, and Botrytis cinerea with inhibitory to be 53.57%, 66.67% and 24.44%, respectively.

Synthesis of 2, 6-(substituded)pyridine Derivatives Using Amide and Imine Groups

A new wo-armed?acyclic diamide Ia 2, 6-bis(1-ethanecarbozamido-2-amino)pyridine, and a new series of aromatic aldehyde schiff bases containing pyridine ring and amide bridge, IIa-f, were prepared. The compounds were characterized by elemental analysis, IR, 1HNMR and MS. The bioactivity half inhibitory concentration C1/2 is given.