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.

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.

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.

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。

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.

2D氢键网络镉配合物Cd(pyridine-2-sulfonato)_2(H_2O)_2和锌配合物Zn(pyridine-2-sulfonato)_2(H_2O)_2的合成和晶体结构

合成了镉的吡啶-2-磺酸配合物Cd(C5H4NSO3)2(H2O)2 1和锌的吡啶-2-磺酸配合物Zn(C5H4NSO3)2(H2O)2 2。 研究表明, 2个化合物属异质同晶, 均属单斜晶系, 空间群为C2/c. 化合物1晶胞参数为:a = 13.7671(5), b = 7.2778(3), c = 16.1559(9) ? b = 106.656(3)? V = 1550.8(1) 3, Z = 4, Dc = 1.990 g/cm3, m =1.719 mm-1, F(000) = 920, R = 0.0225, wR = 0.0584, 共收集到1759个独立衍射点, 其中I≥2(I)的可观测点为1681个;化合物2晶胞参数为:a = 13.711(1), b = 7.1451(9), c = 15.972(1) , b =107.079(5)? V = 1495.7(3) 3, Z = 4, Dc = 1.855 g/cm3, m = 1.964 mm-1, F(000) = 848, R = 0.0310, wR = 0.0831, 共收集到1707个独立衍射点, 其中I≥2(I)的可观测点为1592个。在2个标题配合物中, Cd2+离子(或Zn2+离子)由2个吡啶-2-磺酸中的2个氮和2个氧以及2个水分子中的2个氧配位形成畸变的N2O4八面体配位构型。每个配合物分子具有晶体学2次旋转轴对称性。配合物分子之间通过许多OH(配位水分子)LO(未配位磺酸根)氢键联结成二维结构网络。

离子化合物[2,6-bis(Benzimidazol-2-yl)pyridineH_2]^(2+)·[SbCl_5]^(2-)的合成、晶体结构及荧光性质

利用邻苯二胺、2,6-吡啶二甲酸与三氯化锑在盐酸溶液中经水热反应,合成了一种新的离子型化合物[2,6-bis(Benzimidazol-2-yl)pyridineH2]2+.[SbCl5]2-。通过化学分析、元素分析、热重分析、红外光谱及荧光光谱对结构和性质进行了表征,用X-射线单晶衍射测定了该化合物的晶体结构。化合物的晶体属三斜晶系,P1空间群。Sb3+与其周围5个氯离子配位,构成一个畸变四方锥构型[SbCl5]2-配位结构,2个配阴离子[SbCl5]2-之间通过Sb(1)…Cl(1)ii次级键形成四元环状结构,并与2,6-二(苯并咪唑-2′)吡啶两价阳离子,通过离子键及氢键形成三维网状离子化合物晶体。该化合物具有很好的荧光特性。

CuI-pyridine-β-CD包合物的合成、表征及应用

为了改善CuI-pyridine配合物的物理性质,采用溶液搅拌法合成了CuI-pyridine配合物与β-CD的包合物,用IR、1HNMR、荧光光谱等分析方法对其进行了表征,并用电分析方法初步研究了各种气体对包合物修饰膜电极的响应。结果表明,CuI-pyridine-β-CD包合物为水溶性的荧光化合物(固体状态时EMmax=563 nm),荧光发射稳定;随着甲烷气体不断通入,包合物荧光强度逐渐降低,且甲烷气体对CuI-pyridine-β-CD包合物膜有显著的响应。

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.

掺Pyridine-1有机改性硅凝胶制备及其性质

用正硅酸乙酯（ＴＥＯＳ）和甲基三甲氧基硅烷（ＭＴＭＳ）为共先驱体，采用溶胶－凝胶工艺制备了掺Ｐｙｒｉｄｉｎｅ－１的有机改性硅凝胶。用差热分析（ＤＴＡ）和ＦＴＩＲ研究了凝胶的热稳定性和结构。测定了凝胶的吸收光谱和荧光光谱。

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.

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.

Synthesis and characterization of novel star-shaped pyridine cored compounds with alternating carbazole and triphenylamine moieties

Amorphous 2,4,6-trissubstituted pyridines containing three peripheral carbazole or two triphenylamine and one carbazole moieties, respectively, have been synthesized and characterized. The properties of the compounds are investigated by UV-vis absorption, photoluminescence spectroscopy, thermal analysis as well as cyclic voltammetry. The results show that the compounds have high thermal stability, emit blue light. Also, the compounds possess the HOMO and LUMO energy levels comparable to those of NPB. The effects of different substituents on the electronic properties of the materials have been discussed.

Kinetic hydrate inhibitor performance of new copolymer poly(N-vinyl-2-pyrrolidone-co-2-vinyl pyridine)s with TBAB

In oil and gas field, the application of kinetic hydrate inhibitors （KHIs） independently has remained problematic in high subcooling and high water-cut situation. One feasible method to resolve this problem is the combined use of KHIs and some synergists, which would enhance KHIs’ inhibitory effect on both hydrate nucleation and hydrate crystal growth. In this study, a novel kind of KHI copolymer poly（N-vinyl-2-pyrrolidone-co-2-vinyl pyridine）s （HGs） is used in conjunction with TBAB to show its high performance on hydrate inhibition. The performance of HGs with different monomer ratios in structure II tetrahydrofuran （THF） hydrate is investigated using kinetic hydrate inhibitor evaluation apparatus by step-cooling method and isothermal cooling method. With the combined gas hydrate inhibitor at the concentration of 1.0 wt%, the induction time of 19 wt% THF solution could be prolonged to 8.5 h at a high subcooling of 6℃. Finally, the mechanism of HGs inhibiting the formation of gas hydrate is proposed.

Studies on the Synthesis of Pyridine Analogs of the Natural Product3,5,4'-Trimethoxystilbene

Five pyridine analogs of the natural product, 3, 5, 4'-trimethoxystilbene, were synthesized. The final compounds were characterized by 1H-NMR.

Synthesis,Crystal Structure,DFT Studies and Biological Activity of a Novel Schiff Base Containing Triazolo[4,3-a]pyridine Moiety

The novel Schiff base（E）-8-chloro-NA-（4-（dimethylamino）benzylidene）-[1,2,4]triazolo[4,3-a]pyridine-3-carbohydrazide was synthesized and characterized by ^1H NMR,MS,elemental analysis and X-ray diffraction.The compound crystallizes in the monoclinic space group P2_1/c with a = 7.091（2）,b = 10.750（3）,c = 21.380（6） A,β = 96.299（6）°,V = 1619.7（8） A^3,Z = 4 and R = 0.0351.Theoretical calculation of the title compound was carried out with the B3LYP/6-31 G basis set.The frontier orbital energy and atomic net charges were discussed.It is found that the experimental data show good agreement with the calculated values.And the compound exhibits good antifungal activity against Stemphylium lycopersici（Enjoji） Yamamoto.

A novel synthesis of pyrazolo[3,4-b]pyridine derivatives through multi-component reaction in ionic liquid

An efficient and novel procedure for the preparation of pyrazolo[3,4-b]pyridine derivatives through multi-component reaction of aldehyde, 5-amino-3-methyl-1-phenylpyrazole and malononitrile or cyanoacetate in [bmim][BF4] is described in this paper. Advantages of the method presented here include mild conditions, high yields together with a green nature and ease of recovery and reuse of the reaction medium.

Highly selective methanol-to-olefin reaction on pyridine modified H-mordenite

The effects of the acid site in main channels of MOR zeolites on their product selectivity and deactivation in the MTO（methanol to olefin） reactions were investigated. The catalytic analysis demonstrates that the pyridine modified MOR zeolite yielded high selectivity（> 65.3%） of C;-C;, although the conversion dropped from 100% to 54%. Furthermore, both the catalytic lifetime of MOR and the stability of yielding the lower olefins were increased from less than 30 min to more than 120 min after the modification with pyridine.1H MAS NMR on MOR and modified MOR shows that the acid sites in main channel do not benefit the productivity of lower olefins and catalysts’ lifetime. It can be concluded from ex-situ;C CP MAS NMR that the deposit species during the MTO reaction depend on the pore sizes, and the formation of large alkyl aromatic species more likely occurs in the 12-ring main channels rather than the 8-ring side pocket.

Synthesis of derivatives of imidazo[4,5-b]pyridine:Novel sulfur contained side chains for macrolide antibiotics

Two series of novel derivatives of imidazo[4,5-b]pyridine were synthesized. These compounds could be used as side chains of semisynthesised ketolide antibiotics. The side chains have free amine group which can attached to ketolide core. Macrolides with this kind of side chains will show obvious activities against erythromycin-resistant strains. The structure of the side chains was confirmed by ^1H, ^13C NMR, MS, HMBC spectra. 2007 Ping Sheng Lei. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.