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Keto-form directed hierarchical chiral self-assembly of schiff base derivatives with amplified circularly polarized luminescence

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Chinese Chemical Letters 2024年第1期35卷 366-370页

作者： Yimeng Sun Yuqian Jiang Jian Jiang Tiesheng Li Minghua Liu Green Catalysis Center and College of ChemistryZhengzhou UniversityZhengzhou 450001China Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China National Laboratory for Molecular Science(BNLMS) CAS Laboratory of ColloidInterface and Chemical ThermodynamicsInstitute of ChemistryChinese Academy of ScienceBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China

While enol-keto tautomerism has attracted great interest in schiff bases and related compounds in solution and crystal states,the self-assembly of energy-unfavored keto form were scarcely investigated.Here,we report a keto-form directed self-assembly of a naphthalene-attached enantiomeric N-salicylideneanil analog L/DGG-Nap accompanied with a significantly amplified circularly polarized luminescence(CPL).It was found that LGG-Nap exists as a mixture of enol and keto form in monomer at a diluted toluene solution.The increment of the concentrations leads to the formation of predominated keto form,which subsequently triggers the self-assembly.Cryo-transmission electron microscopy(Cryo-TEM)revealed that a hierarchical assembly process happened upon increasing the concentration of LGG-Nap in toluene.Individual nanofibers formed at 1×10-4 mol/L and transferred into helical nanofiber bundles in 5×10-3 mol/L.Interestingly,while these is nearly no circular dichroism(CD)or CPL in the monomeric solution,the assembly showed strong CD and CPL.Remarkably,the dissymmetry factor(glum)was significantly amplified from zero in solution through the 0.005 in individual nanofiber to 0.1 in nanofiber bundles.This work demonstrates that the enol-keto tautomerism can be broken and trigger the self-assembly upon increasing the concentration,which can subsequently direct the chiral self-assembly and significantly amplify the dissymmetry factor of assembled CPL materials.

关键词： Enol-keto tautomerism Chiral self-assembly schiff base Circularly polarized luminescence Nanofiber bundle

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Synthesis and Characterization of Novel schiff base for Enhanced Dye-Sensitized Solar Cell Photo-Response Mechanism

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Crystal Structure Theory and Applications 2024年第2期12卷 11-20页

作者： Raphael Shadai Oguike Hanatu Akanagn Omolara Oni Corrosion Protection and Materials Science Laboratory Chemistry Department Abubakar Tafawa Balewa University Bauchi Nigeria

The efficient photo-response mechanism is one of the key factors in the commercialization of dye-sensitized solar cells in a bid to satisfy renewable energy demands. Progress in green technology has put solar energy on the front burner as a provider of clean and affordable energy for a sustainable society. We report the synthesis of a novel schiff base with optical transparency in the visible and near IR region of the solar spectrum that can find application in the DSSCs photo-response mechanism. The synthesized crystal exhibited features that could handle some of the shortcomings of dye-sensitized solar cells which include wide band solar spectrum absorption and capability for swift charge transfer within the photoelectrodes. The synthesized schiff base was characterized using x-ray diffractometer, UV/Visible spectrometer, Frontier transmission infrared spectrometer and conductometer. XRD data revealed the grown crystal to have an average crystallite size of 2.08 nm with average microstrain value of about 269.43. The FT-IR recorded transmission wave ѵ (CO) at 1207.7 cm−1 while dominant wave occurred at ѵ1654.9 and ѵ1592.3 cm−1 relating to ѵ (CN) stretching and ѵ (NH) bending respectively were observed. The IR spectrum revealed the bonding species and a probable molecular structure of 2,6-bis(benzyloxy)pyridine. The UV/Visible spectra convoluted to maximum peak within the near IR region suggesting that 2,6-bis(benzyloxy)pyridine can absorb both the visible and near IR region while its electrical conductivity was determined to be 4.58 µS/cm. The obtained result of the present study revealed promising characteristics of a photosensitizer that can find application in the photo-response mechanism of DSSCs.

关键词： Dye-Sensitized Solar Cell schiff base Photosensitizer Optical Transparency Benzil Pyridine

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Syntheses,Crystal Structures and Property of Pyridine Zinc(Ⅱ)Complexes based on Halogenated Salicylaldehyde schiff base

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Chinese Journal of Structural Chemistry 2022年第3期41卷 12-18,I0007页

作者：蒋伍玖倪鹏辉毛芳芳谭宇星 Key Laboratory of Functional Metal-organic Compounds of Hunan Province Key Laboratory of Organometallic New MaterialsCollege of Hunan ProvinceHunan Provincial Engineering Research Center for Monitoring and Treatment of Heavy Metals Pollution in the Upper Reaches of Xiangjiang RiverCollege of Chemistry and Materials ScienceHengyang Normal UniversityHengyangHunan 421008China

schiff base pyridine zinc(II)complexes 1~4 were synthesized by the reaction of the 2-((2-hydroxybenzylidene)amino)phenol schiff base with appended donor functionality,zinc acetate,and pyridine.The results of the structural characterization of the complex show that they have the same coordination mode and similar steric structure.Complexes 1 and 3 form a one-dimensional chain structure and two-dimensional grid struc-ture by lots of hydrogen bonds,respectively.Thermogravimetric analysis shows complexes 1~4 can exist stably be-low 150℃.The results of the fluorescence quenching experiments between the complexes and DNA-EB show that the interaction between them is intercalation,and the effect of complex 1 is the most obvious.It is speculated that the steric hindrance of complex 1 is relatively small,and the aromatic ring on the ligand is more likely to inserted into the base pair of DNA.

关键词： zinc complex schiff base synthesis crystal structure property

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schiff-base-rich g-C_(x)N_(4) supported PdAg nanowires as an efficient Mott-Schottky catalyst boosting photocatalytic dehydrogenation of formic acid

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Rare Metals 2021年第4期40卷 808-816页

作者： Hu Liu Xue-Xiang Li Xin-Yang Liu Zhen-Hui Ma Zhou-Yang Yin Wei-Wei Yang Yong-Sheng Yu School of Chemistry and Chemical Engineering Xi’an University of Architecture and TechnologyXi'an 710055China School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi'an 710072China MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China Department of Chemistry Brown UniversityRI 02912USA

Developing an efficient photocatalyst,catalyzing formic acid(FA) dehydrogenation,can satisfy the demand of the H_(2) energy.Herein,a graphitic carbon nitride(gC_(x)N_(4))-based nanosheet(x=3.2,3.6 or 3.8) with melem rings conjugated by schiff-base bond(N=C-C=N) was synthesized,tuning the bandgaps(Eg) of graphitic carbon nitride(g-C_(3) N_(4)) in the range of 1.8 400 nm) without any additive at 25℃,which is the best value among ever-reported ones.This work provides a new strategy to boost dehydrogenation photocatalysis of FA,which will be promising for practical application of H2 in future energy field.

关键词： Dehydrogenation of formic acid Graphitic carbon nitride schiff base PdAg nanowires Mott-Schottky heterojunction

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Synthesis, Thermal, Electrical and Catalytic Studies of Some Transition Metal Polychelates of Bis-bidentate schiff base

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Chinese Journal of Chemistry 2007年第2期25卷 154-158页

作者： BANSOD, Ashish ASWAR, Anand Department of Chemistry S.G.B. Amravati University Amravati -444602 (MS.) India

Polychelates of Mn（Ⅱ）, Fe（Ⅱ）, Co（Ⅱ）, Ni（Ⅱ）, Cu（Ⅱ）, Zn（Ⅱ） and Cd（Ⅱ） with the bis salen-type ligand derived from 4,4＇-bis[（salicylaldehyde-5）azo]biphenyl and 1,4-diaminobutane have been synthesized. All the polychelalls have been characllrized by elemental analysis, magnetic susceptibility measurements, IR, electronic spectra and thennogravirncuic studies. All the complexes isolated in solid stall are dark coloured and insoluble in water and common organic solvents. The ligand behaves as a bis-bidentall molecule coordinating through the phenolic oxygen and azomethine nitrogen atoms. The thermal decomposition of these metal complexes was investigated by thermogravimetric analysis and data have been analyzed for kinetic parameters using Broido equation. The solid-state electrical conductivity of the ligand and its polychelalls in the form of compressed pellet was studied in the temperaturc range from 313 to 413 K All the polychelalls were found to show semiconducting nature. The Mn（Ⅱ）, Fe（Ⅱ）, Co（Ⅱ） and Ni（Ⅱ） polychelalls have been assessed for the catalytic epoxidation of styrene.

关键词： schiff base polychelate TGA solid-state conductivity catalytic activity

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Syntheses,Crystal Structures and Kinetic Mechanisms of Thermal Decomposition of Rare Earth Complexes with schiff base Derived from o-Vanillin and p-Toluidine

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Journal of Rare Earths 2006年第3期24卷 268-275页

作者：赵国良冯云龙温一航 College of Chemistry and Life Science Zhejiang Normal University Jinhua 321004 ChinaZhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces Jinhua 321004 China

Three complexes, [Pr（NO3）3（HL）2] （1）, [Nd（NO3）3（HL）2] （2） and [Er（NO3）3（HL）2] ·0.5H2O （3）, were synthesized from the reaction of a schiff base ligand 2-[ （4-methylphenylimino）methyl ]-6-methoxyphenol （C15 H15 NO2, HL） with Ln（NO3）3·6H2O （Ln = Pr, Nd, Er）. Characterization by single-crystal X-ray diffraction technique, elemental analysis, molar conductance, FT-IR, UV-Vis, ^1H NMR and thermal analysis shows the title complexes are neutral molecules where the central Ln（ Ⅲ） ion is ten-coordinated in biapical anti-hexahedron prism geometry, with four oxygen atoms of the phenolic hydroxy and methoxy groups in the two bidentate schiff base ligands and six oxygen atoms provided by the three bidentate NO3 - anions. Additionally, the kinetic mechanism of thermal decomposition of complex 3 was determined with a TG-DTG curves by both integral and differential methods. The functions of thermal decomposition reaction mechanism and the equation of kinetic compensation effect were obtained.

关键词： o-vanillin p-toluidine schiff base crystal structure kinetic mechanism of thermal decomposition rare earths

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Synthesis and Pyrolysis of Soluble Cyclic Hf-schiff base Polymers

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Chinese Journal of Polymer Science 2021年第6期39卷 659-664,I0005页

作者： Yu-Huan Wu Li Ye Ya-Nan Sun Wei-Jian Han Tong Zhao Key Laboratory of Science and Technology on High-tech Polymer Materials Institute of ChemistryChinese Academy of SciencesBeijing 100190China University ofChinese Academy of Sciences Beijing 100049China

Soluble Hf-containing polymers are significant processable precursors for the fabrication of ultra-high temperature ceramics.In this work,cyclic Hf-schiff base polymers were synthesized via direct polymerization of hafnium alkoxide and bis-salen monomers.The defined structure and molecular weight of the polymers were characterized by NMR spectroscopy,gel permeation chromatography and MALDI-TOF mass spectroscopy.The feed ratio of monomers regulated the molecular weight and solubility of the polymers.This synthetic strategy features simple operation under ambient conditions,efficient reaction with high yield and cyclic polymers as the main products.The Hf-schiff base polymers were converted to HfC/C materials after pyrolysis under argon at 1600°C,which was identified by XRD measurements,elemental analyses and Raman spectroscopy.This work will inspire more precise and efficient synthesis and applications of metallopolymers.

关键词： Hf-containing polymer schiff base Cyclic polymer Preceramic polymer Hafnium carbide

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Synthesis,Crystal Structure and Quantum Chemical Investigation of Bis-schiff base Compounds Derived from2-phenyl-1,2,3-triazole-4-carboxaldehyde with Diamine

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Chinese Journal of Structural Chemistry 2008年第5期27卷 616-621页

作者： XIE Ling LIU Gang WANG Yan WANG Ji-De CHEN Jun-Feng Department of Chemistry Key Laboratory of Oil ＆ Gas Fine Chemicals Ministry of Education Xinjiartg University Urumqi 830046 China

Two new schiff base N,N＇-bis（（2-phenyl-2H-1,2,3-triazol-4-yl）methylene）-1,3-propanediamine （1） and N,N＇-bis（（2-phenyl-2H-1,2,3-triazol-4-yl）methylene） -1,4-butanediamine （2） were synthesized by condensation of 2-phenyl-1,2,3-triazole-4-carboxaldehyde with diamine, and characterized by elemental analysis, IR, IH NMR and MS spectra. Their crystal structures were determined by X-ray single crystal diffraction. Both crystals belong to the monoclinic system, space group P21/c. For compound 1（C21H20N8, Mr=384.45）： a = 16.314（3）, b =5.7168（11）, c = 21.316（4） A, β = 105.3（2）°, Z = 4, V = 1917.6（7） A^3, De =1.332 g/cm^3, F（000） = 808,μ = 0.086 mm 1, R = 0.0533 and wR = 0.1460; for compound 2 （C22H22N8, Mr=398.48）： a = 8.6156（17）, b = 5.2964（11）, c = 22.665（5）A, β = 100.54（3）°, Z = 2, V = 1016.8（4） A^3, De= 1.302 g/cm^3, F （000） = 420, μ = 0.083 mm^-1, R = 0.0373 and wR = 0.1155. based on the crystal data, quantum chemistry calculation was performed on the two title compounds by means of Gaussian 98 program. The molecular orbital energies and atomic net charges population were obtained. Furthermore, we antilyzed their active atoms. The investigation can serve as a theoretical guide to study the synthesis and activity of the title compounds.

关键词： schiff base crystal structure quantum chemical calculation

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Heterogeneous Green Catalyst for Oxidation of Cyclohexene and Cyclooctene with Hydrogen Peroxide in the Presence of Host （Nanocavity of Y-zeolite）/Guest （N4-Cu（II） schiff base Complex） Nanocomposite Material

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Chinese Journal of Chemistry 2011年第11期29卷 2439-2444页

作者： Lashanizadegan, Maryam Rayati, Saeed Dejparvar Derakhshan, Zeinab Department of Chemistry Faculty of Science Alzahra University Vanak Tehran P. O *** Iran Department of Chemistry K. N. Toosi University of Technology Tehran P. O. Box 16315-1618 Iran

Copper（If） complex of a schiff base ligand derived from pyrrolcarbaldehyde and o-phenylenediamine （H2L） has been synthesized and encapsulated in Y-zeolite matrix. The hybrid material has been characterized by elemental analysis, IR and UV-Vis spectroscopic studies as well as X-ray diffraction （XRD） pattern. The encapsulated cop- per（II） catalyst is an active catalyst for the oxidation of cyclooctene and cyclohexene using H202 as oxidant. Under the optimized reaction conditions 81% conversion of cyclohexene with 65% selectivity for 2-cyclohexenone formation and 87% conversion of cyclooctene with 46% selectivity for epoxide formation were obtained.

关键词： schiff base copper zeolite hydrogen peroxide catalyst

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A New Method of Synthesis of Azo schiff base Ligands with Azo and Azomethine Donors： Synthesis of N-4-Methoxybenzylidene-2-（3-hydroxyphenylazo）-5-hydroxyaniline and Its Nickel（Ⅱ） Complex

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Chinese Journal of Chemistry 2007年第6期25卷 869-871页

作者： OFORKA, N. C. MKPENIE, V. N. Department of Pure and Industrial Chemistry University of Port Harcourt P. M. B. 5323 Port Harcourt Nigeria

A new method for the synthesis of azo schiff an base ligand in which the azo and azomethine groups are coordination sites was developed through a schiff base precursor. The precursor, N-4-methoxybenzylidene-3-hydroxyphenylamine （SB） derived from 3-aminophenol was regioselectively coupled with a diazonium ion para to the hydroxyl group of the amine component of the schiff base. The para selectivity was controlled by the directing effect of the hydroxyl group. The ligand and its nickel（Ⅱ） complex were characterized by elemental analyses, IR and UV-Vis spectroscopy. The analytical and spectral data supported the mononuclear formulation of the complex with metal to ligand ratio （M ： L = 1 ： 2） and suggested a square planar geometry for the complex.

关键词： synthesis azo compound schiff base ligand azo and azomethine donor

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