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.

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.

Boosting Fischer-Tropsch Synthesis via Tuning of N Dopants in TiO_(2)@CN-Supported Ru Catalysts

Nitrogen(N)-doped carbon materials as metal catalyst supports have attracted signifi cant attention,but the eff ect of N dopants on catalytic performance remains unclear,especially for complex reaction processes such as Fischer-Tropsch synthesis(FTS).Herein,we engineered ruthenium(Ru)FTS catalysts supported on N-doped carbon overlayers on TiO_(2)nanoparticles.By regulating the carbonization temperatures,we successfully controlled the types and contents of N dopants to identify their impacts on metal-support interactions(MSI).Our fi ndings revealed that N dopants establish a favorable surface environment for electron transfer from the support to the Ru species.Moreover,pyridinic N demonstrates the highest electron-donating ability,followed by pyrrolic N and graphitic N.In addition to realizing excellent catalytic stability,strengthening the interaction between Ru sites and N dopants increases the Ru^(0)/Ru^(δ+)ratios to enlarge the active site numbers and surface electron density of Ru species to enhance the strength of adsorbed CO.Consequently,it improves the catalyst’s overall performance,encompassing intrinsic and apparent activities,as well as its ability for carbon chain growth.Accordingly,the as-synthesized Ru/TiO_(2)@CN-700 catalyst with abundant pyridine N dopants exhibits a superhigh C_(5+)time yield of 219.4 mol CO/(mol Ru·h)and C_(5+)selectivity of 85.5%.

A New Diiminopyridyl Cobalt Complex [CoCl_2L](L=2,6-Bis(N,N'-bis(2,6-diisopropyl-4-(2,3-dimethyoxylbenzoylamide)phenylimino))pyridine)

The reaction of CoCl2·6H2O with 2,6-bis（N,N＇-bis（2,6-diisopropyl-4-（2,3-dimethy-oxyl-benzoylamide）phenylimino））pyridine（L） afforded the complex [CoCl2L],which was fully characterized by elemental analysis,UV-vis,IR spectroscopy,fluorescence,and X-ray diffraction analysis.The compound is of triclinic system,space group P1 with a = 13.058（3）,b = 13.798（3）,c = 16.695（3） ,α = 98.191（3）,β = 102.792（3）,γ = 101.820（3）°,V = 2815.0（9） 3,Z = 2,F（000） = 1122,μ = 0.45 mm-1,R = 0.061 and wR = 0.1349 for 9842 observed reflections（Ⅰ 〉 2σ（Ⅰ））.The Co（Ⅱ） center adopts a distorted square-pyramidal coordination geometry.The extended structure shows a one-dimensional zigzag double chain linked by hydrogen bonds and π-π stacking interactions.

Synthesis and Crystal Structure of Fe(aapo)_2Cl_3(aapo=2-Acetylamino Pyridine N-Oxide)

The complex Fe(aapo)2Cl3 with chemical formula C14H16Cl3FeN4O4 was obtained by the reaction of FeCl36H2O with apoHCl (apo = 2璦mino pyridine N璷xide) in acetonitrile. The result shows that CH3CN has been hydrolysised with the water from FeCl36H2O dissolving, and then the hydrolysised product condenses with apo to give aapo. A single-crystal X璻ay study of Fe(aapo)2Cl3 shows it belongs to the monoclinic system, space group C2/c with a = 15.873(3), b = 10.322(2), c = 11.987(2) ? b = 106.35(1), V = 1884.5(6) 3, Z = 4, Mr = 466.51, Dc = 1.644 g/cm3, m(MoKa) = 1.253 mm-1, F(000) = 948, R = 0.0377 and wR = 0.0749 for 1262 observed reflections with I > 2(I). Fe (Ⅲ) is coordinated by a trigonal bipyramidal geometry with three chlorine atoms lying on the equatorial plane and two oxygen atoms connected with the nitrogen atoms of pyridine rings occupying the axial positions, while the iron and Cl(1) atoms lie on the crystallographic 2-fold axis. The dihedral angle of two pyridine rings is 71.74(9). There exist N(2)H(2)…O(1)?hydrogen bonds in the crystal structure.

Catalyst Free Synthesis of Pyridine-2,6-bis(2-bromo-propane-1,3-dione) and Pyrdine-2,6-bis(<i>N</i>-arylthiazoline-2-thiones)

We have described herein a catalyst-free preparation method of pyridine-2,6-bis(N-alkylthiazoline-2-thiones) (4a-i) by the reaction of primary amines, CS2, and pyridine-2,6-bis(2-bromo-1,3- dicarbonyl) derivatives (2a-c) in water. Also, we have described a catalyst free, green chemistry protocols to monobromination of pyridine-2,6-bis(2-bromo-1,3-dicarbonyl) derivatives with high yield, using NBS as a brominating agent, that led to eco-friendly isolation and purification proce-dures. Furthermore, we have studied the reactivity of pyridine-2,6-bis(2-bromo-1-methyl-pro- pane-1,3-dione) (2a) towards thiourea to afford 2,6-bis(5-benzoyl-2-aminothiazol-4-yl)pyridine (9).

Spectral Properties and Solubilization Location of 2′-Ethylhexyl 4-（N,N-Dimethylamino）benzoate in Micelles

Dual fluorescence and UV absorption of 2′-ethylhexyl 4-（N,N-dimethylamino）benzoate （EHDMAB） were investigated in cationic, non-ionic and anionic micelles. When EHDMAB was solubilized in different micelles, the UV absorption of EHDMAB was enhanced. Twisted intramolecular charge transfer （TICT） emission with longer wavelength was observed in ionic micelles, whereas TICT emission with shorter wavelength was obtained in non-ionic micelles. In particular, dual fluorescence of EHDMAB was significantly quenched by the positively charged pyridinium ions arranged in the Stern layer of cationic micelles. UV radiation absorbed mainly decays via TICT emission and radiationless deactivation. The dimethylamino group of EHDMAB experiences different polar environments in ionic and non-ionic micelles according to the polarity dependence of TICT emission of EHDMAB in organic solvents. In terms of the molecular structures and sizes of EHDMAB and surfactants, each individual EHDMAB molecule should be buried in micelles with its dimethylamino group toward the polar head groups of different micelles and with its 2′-ethylhexyl chain toward the hydrophobic micellar core. Dynamic fluorescence quenching measurements of EHDMAB provide further support for the location of EHDMAB in different micelles.

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.

Heterosynthesis Using Nitriles: Novel Pyrrolo[2,3-<i>b</i>]pyridines

2-Amino-4-benzoyl-1-arylpyrrole-3-carbonitriles react with arylidene malonodinitriles, β-ketoesters and β- diketones to afford pyrrolo[2,3-b]pyridine derivatives.

Kinetic Study of Atom Transfer Radical Polymerization of 2-(N,N-Dimethylamino)ethyl Methacrylate

A kinetic model was developed to describe the atom transfer radical polymerization (ATRP) of 2(N,N-dimethylarnino) ethyl methacrylate (DMAEMA). The model was based on a polymerization mechanism, which included the atom transfer equilibrium for primary radical, the propagation of growing polymer radical, and the atom transfer equilibrium for the growing polymer radical. An experiment was carried out to measure the conversion of monomer, the number-average molecular weight of polymer and molecular weight distribution for the ATRP process of DMAEMA. The experimental data were used to correlate the kinetic model and rate constants were obtained. The rate constants of activation and deactivation in the atom transfer equilibrium for primary radical are 1.0 x 10(4) L(.)mol(-1.)s(-1) and 0.04 L(.)mol(-1.)s(-1), respectively. The rate constant of the propagation of growing polymer radical is 8.50 L(.)mol(-1.)s(-1), and the rate constants of activation and deactivation in the atom transfer equilibrium for growing polymer radical are 0.045 L(.)mol(-1.)s(-1) and 1.2 x 10(5) L(.)mol(-1.)s(-1), respectively. The values of the rate constants represent the features of the ATRP process. The kinetic model was used to calculate the ATRP process of DMAEMA. The results show that the calculations agree well with the measurements.

两种咔唑基-吡啶-N-氧化物内盐荧光极性探针研究

合成了4-(9H-咔唑-9-基)吡啶1-氧化物(CPNO)和4-(4-(9H-咔唑-9-基)苯基)吡啶1-氧化物(CPPNO)两种咔唑基-吡啶-N-氧化物内盐,测定了它们在不同溶剂中的紫外-可见吸收和荧光光谱,均表现出对溶剂极性较好的敏感性。计算表明,两个化合物都具有较大的激发态偶极矩,是化合物溶剂极性敏感性的原因。研究为开发新型的荧光极性探针提供了一种新思路。

Synthesis of Poly[(3-octanoylpyrrole-2,5-diyl)-p-(N,N-dimethylamino)benzylidene] and Its Properties by Nitrogen Ion Implantation

A novel soluble π-conjugated polymer, poly[(3-octanoylpyrrole-2,5-diyl)-p-(N,N-dimethylamino)benzylidene](POPDMABE), was synthesized firstly by the condensation of 3-octanoylpyrrole with para-dimethylaminobenzaldehyde. The chemical structure of the polymer was characterized by FTIR and 1H NMR spectrometries. The polymer is a potential nonlinear optical(NLO) material. According to the function of optical forbidden band gap(E_g) and photon energy(hν), the optical forbidden band gaps of the polymer before and after ion implantation were calculated. The resonant third-order nonlinear optical properties of POPDMABE before and after ion implantation were also studied by using the degenerate four-wave mixing(DFWM) technique at 532 nm. When the energy is 25 keV and the dose is 2.2×10 17 ions/cm 2, the {polymer′s} optical forbidden band gap is about 1.63 eV which is smaller than that of the non-implanted sample(1.98 eV) and the resonant third-order NLO susceptibility of POPDMABE is about 4.3×10 -7 esu, 1 order of magnitude higher than that of the non-implanted sample(4.1×10 -8 esu). The results show that nitrogen ion implantation is an effective method to improve the resonant third-order NLO property of the polymer.

6-(N,N-Dimethylamino)-2-naphthoylacryl Acid:a Highly Selective and Sensitive Fluorescent Sensor of Copper(Ⅱ)

A novel fluorescent probe,6-（N,N-dimethylamino）-2-naphthoylacryl acid（ACADAN） was designed and synthesized as a fluorescent sensor for Cu^2＋ in aqueous media.Significant amplification of fluorescence signals without causing any discernible change of maximum fluorescence emission wavelength（λ max） was observed upon the addition of Cu^2＋.Importantly,ACADAN is capable of recognizing Cu^2＋ selectively in aqueous media in the presence of various biologically relevant metal ions and the prevalent toxic metal ions in the environment with high sensitivity（detection limit was 0.1 μmol/L）.

Synthesis and Crystal Structure of Diethyl-2,6-dimethyl-3,5-diyl-(1-(2-chlorobenzoyl)-1H- pyrazole-3-diethyl-carboxylate)-pyridine

The reaction of hydrazine hydrate with a new α,γ-diketone ester 3, derived from the reaction of 2,6-dimethyl-3,5-diacetyl-pyridine 2 with diethyl oxalate in the presence of sodium ethoxide, afforded the pyrazole derivative 4. Treatment of 4 with 2-chlorobenzoyl chloride gave diethyl 2,6-dimethyl-3,5-diyl-（1-2（chlorobenzoyl）-1H-pyrazole-3-diethyl-carboxylate） pyridine 5. Fine crystal of 5 suitable for XRD analysis was obtained form recrystalization in ethyl acetate. The crystal belongs to the triclinic system, space group P1^-, with a = 1.0342（11）, b = 1.2211（12）, c = 1.5013（15） nm, α = 82.5190（10）,β = 85.7960（10）,γ = 85.3150（10）°, V= 1.8697（3） nm^3, Dc= 1.173 g/cm^3, μ = 0.219 mm^-1, F（000） = 684, Z = 2, the final R = 0.0720 and wR = 0.2211.

Synthesis and Magnetic Properties of Copper (Ⅱ) Complexes with Pyridine N-Oxide-2-ylmethy-lidenedithiocarbazate as Ligands

A series of copper (Ⅱ) complexes with pyridine N- oxide- 2- ylmethylidened-ithiocarbazates as ligands were synthesized and characterized by IR spectra, electronic spectra and magnetic moments measurement at room temperature. Variable temperature magnetic susceptibilites (3-300K) of four complexs were measured and fitted with the Bleaney-Bowers dimer equation by considering the magnetic interaction between molecules. The fitting results show the existence of intramolecular ferromagnetic interactions and intermolecu-lar anti-ferromagnetic interactions in these copper( Ⅱ) complexes.

ZnⅡ NiⅡ, and MnⅡ Complexes Supported by N-Hydroxy-pyridine-2-carboxamidine： Syntheses, Structures, and Luminescent and Magnetic Properties

The employment of N-hydroxy-pyridine-2-carboxamidine in the coordination chemistry of zinc（II）, nickel（II） and manganese（II） under solvothermal conditions is reported. Four complexes of compositions, [Zn2（O2CMe）3{（py）C（NH2）NOH}4]（OH） （1）, [Zn4（OH）2{（py）C（NH2）- NO}4CI2]＇3MeCN （2）, [Ni（SO4）（H20）{（py）C（NH2）NOH}2]＇H2O （3） and [Mn（SO4）{（py）C（NH2）- NOH}2]n （4）, have been synthesized by rationally choosing different metal salts and dexterously employing acetate and sulfate ions as the bridging groups. Luminescent properties for 2 suggested strong emission in the solid state at room temperature. Variable temperature （2.0-300 K） magnetic studies for the linear chain complex 4 indicate weak antiferromagnetic Mn（Ⅱ）...Mn（Ⅱ） exchange interactions.

Crystal and Molecular Structure of Copper (Ⅱ) Dimeric Complex of S-Methyl-β-N-(Pyridine N-Oxide-2-ylmethylidene) Dithiocarbazate with Acetonitrile

The crystal and molecular structure of copper(Ⅱ) dimeric complex of S-methyl-B-N-(pyridine N-oxide-2-ylmethylidene) dithiocarbazate with acetonitrile, [CuL (CH3CN)]2 (ClO4)2, was determined by X-ray diffraction. The complex crystalizes in monoclinic system with space group P21/n, a= 7. 685(2), 6=20.160(6), c= 10. 847(5) A ,B = 107.89(3), Z=2,Dc=1.788 g/cm3, F(000) = 835. 8, u= 18. 17 cm-1(Moka,R= 0. 057.Each Cu(Ⅱ) ion in the complex is surrounded by a distorted square pyramidal. The basal plane is comprised of S, N and O atoms of one ligand together with a N atom of the solvent--acetonitrile, while the axial position is occupied by the S atom of the other ligand. The bond length of Cu-S(bridging) is 3. 038A . and Cu-Cu distance is 3. 700A.

Synthesis,Crystal Structure and Photoluminescence Property of Ag(I)with N,N-dimethyl-4-(pyridine-4-yldiazenyl)aniline

A 2D plane coordination compound [Ag_2（Dpya）_2.（NO_3）_2]n was synthesized and characterized by FT-IR,elemental analysis and TG analysis.The red crystal was obtained via solvent diffusion method at room temperature and is slightly soluble in organic solvents.Its structure was determined by single-crystal X-ray diffraction analysis.It crystallizes in monoclinic,space group P1 with a = 10.7995（13）,b = 7.4748（8）,c = 18.364（2） A,β = 98.916（4）o,V = 1464.5（3） A^3,Z = 2,C_（26）H_（28）Ag_2N_（10）O_6,M_r = 792.32,Dc = 1.302 Mg/m^3,F（000） = 792,μ（Mo Ka） = 1.356 mm^-1,R = 0.0575 and w R = 0.0826.The compound [Ag_2（Dpya）_2.（NO_3）_2]_n is a two-dimensional structure and there are two kinds of coordination configurations about the Ag atoms in the compound.The Ag（1） center is tetrahedrally coordinated with two O atoms of NO_3^-and two N atoms from the ligand Dpya.Meanwhile,the Ag（2） is five-coordinated by five O atoms from three NO_3^-anions.The Ag centers（Ag（1） and Ag（2）） connect to themselves as well as with each other by the bridging NO_3^-anions.And the coordination compound shows photoluminescence with an emission peak at 530 nm（λex = 450 nm） as the ligand Dpya.

The Amperometric Glucose Enzyme Electrode by Immobilized Glucose Oxidase in Glucose Oxidase/N-ethyl-Poly (4-vinyl)pyridine Multilayer

Multilayers of glucose oxidase(GOD)/N-ethyl-poly (4-vinyl) pyridine (EPVP) have been assembled on thiol self-assembled monolayers on gold electrode.This electrode can be used as an amperometric enzyme elcctrode for glucose. Fe (CN)63-/4- incorporated in EPVP layer acts as the electron mediator, the linear range was 0.1 to 6 mmol/L when the number of GOD layers was 5.

Synthesis,Structural Characterization and Catalytic Activity of Copper(Ⅰ)Complexes with Triphenylphosphine and Pyridine Derivatives

Two new Cu（Ⅰ） complexes [CuCl（3-PyOH）（PPh_3）_2]（1） and [Cu_2（μ-Cl）_2（4-Stpy）（Ph_3P）_3]（2）（PyOH = hydroxypyridine; stpy = styrylpyridine） with triphenylphosphine and pyridine derivatives have been synthesized and characterized by elemental analysis and X-ray single-crystal diffraction. Compound 1 crystallizes in monoclinic, space group P2_1/c with a = 9.8945（7）, b = 37.266（2）, c = 10.9461（7） A, β = 116.0750（10）°, V = 3625.3（4） A^3, Z = 4, D_c = 1.350 Mg/cm^（-3）, μ = 0.801 mm^（-1）, F（000） = 1528, the final R = 0.0320 and w R = 0.0729 for 18568 observed reflections（I 〉 2σ（I））, R（all data） = 0.0413, wR（all data） = 0.0769, completeness to theta of 25.01 is 99.9% and GOF = 1.037. Compound 2 crystallizes in monoclinic, space group P2_1/c with a = 11.290（3）, b = 20.388（5）, c = 24.092（6） A, β = 102.028（4）°, V = 5424（2） A^3, Z = 4, D_c = 1.428 Mg/cm^（-3）, μ = 1.016 mm^（-1）, F（000） = 2408, the final R = 0.0568 and w R = 0.1486 for 27644 observed reflections（I 〉 2σ（I））, R（all data） = 0.0716, wR（all data） = 0.1592, completeness to theta of 25.01 is 99.9% and GOF = 1.056. Two new Cu（I） complexes have been utilized as catalysts for N-arylation of imidazole and both showed good catalytic activity.