Five novel ternary complexes of the rare earth ions with o-phenanthroline（Phen） and Schiff base salicylaldehyde L-phenyla- lanine（KHL） were synthesized in ethanol. Their compositions were characterized by elementa...Five novel ternary complexes of the rare earth ions with o-phenanthroline（Phen） and Schiff base salicylaldehyde L-phenyla- lanine（KHL） were synthesized in ethanol. Their compositions were characterized by elemental analysis, molar conductance, ^1H NMR, FT-IR, and Raman spectra. The formulas of the complexes were verified to be RE（L）（Phen）Cl（H2O） （RE=La^3＋, Ce^3＋, Nd^3＋, Er^3＋, and Gd^3＋; L=Schiff base salicylaldehyde L-phenylalanine; phen=o-phenanthroline）. Methyl thiazolyl tetrazolium （MTT） colorimetry and flow cytometry were used to test the anticancer effect of the complexes with K562 tumor cell. The research showed that the complexes could inhibit K562 tumor cell＇s growth, generation, and induce apoptosis. The inhibition ratio was accelerated by increasing the dosage, and it had significant positive correlation with the medication dosage.展开更多
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...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.展开更多
To further explore an efficient modified route for the shift from an antibacterial fluoroquinolone to an antitumor one,mono-Schiff bases 6a-6h related to ciprofloxacin C3 carbonylhydrazone and bis-Schiff bases 4a-4h c...To further explore an efficient modified route for the shift from an antibacterial fluoroquinolone to an antitumor one,mono-Schiff bases 6a-6h related to ciprofloxacin C3 carbonylhydrazone and bis-Schiff bases 4a-4h corresponding to C3/C7 carbonylhydrazone/hydrazone attached on a skeleton of ciprofloquinolone were designed and synthesized,and their in vitro antitumor activity against CHO,HL60,L1210 cells and antibacterial activity against Staphylococcus aureus and Escherichia coli were also reported.展开更多
Owing to its two unsymmetrical-NH2 groups sited on different terminals, 2, 6-diaminocaproic acid (lysine) was used as a reactant for synthesizing a novel unsymmetrical Schiff base with salicylaldehyde on one side and ...Owing to its two unsymmetrical-NH2 groups sited on different terminals, 2, 6-diaminocaproic acid (lysine) was used as a reactant for synthesizing a novel unsymmetrical Schiff base with salicylaldehyde on one side and ovanillin on the other for the first time. It is a new way to synthesize such a special unsymmetrical Schiff base. It is named “hetero bis-Schiff base” for distinguishing it from others. The synthesis method, formation mechanism as well as twelve new lanthaniHe complexes with the above ligand are reported and discussed herein. They were characterized by elementary analysis, molar conductivity, IR-spectra and especially by1H and13C NMR spectra. The results obtained may provide a new promising method for synthesizing similar unsymmetrical Schiff bases and their complexes.展开更多
A pyridine-contained Schiff base ligand L（L =（pyridine-2-vinyl）hydrazine） has been synthesized and fully characterized. By self-assembly of the ligand with HgI2, a binuclear complex Hg2I4L（C） was obtained. The s...A pyridine-contained Schiff base ligand L（L =（pyridine-2-vinyl）hydrazine） has been synthesized and fully characterized. By self-assembly of the ligand with HgI2, a binuclear complex Hg2I4L（C） was obtained. The structures of L and C were analyzed through single-crystal X-ray diffraction. L crystallizes in monoclinic, space group P21/n with a=11.286（5）, b=3.981（5）, c=23.865（5） , β=100.043（5）°, V=1056（1） 3, Z=4, Dc=1.323 g/m3, F（000）=440, Μr=210.24, μ=0.084 mm（-1）, the final R=0.0928 and w R=0.2867 for 6955 observed reflections with I ＆gt; 2（I）. The complex is of monoclinic system, space group P21/n with a=8.706（5）, b=17.468（5）, c=14.675（5） , β=93.922（5）°, V=2227（2） 3, Z=4, Dc=3.338 g/m3, F（000）=1928, Μr=1119.02, μ=19.321 mm（-1）, the final R=0.0366 and w R=0.1276 for 3920 observed reflections with I ＆gt; 2（I）. The structural analysis revealed that the molecule of L possesses a well planar structure. However, in the complex, the coordinated ligand distorts greatly. The absorption spectra of L and the complex in ethanol were experimentally and theoretically studied. The result indicates that the complex exhibits different absorption spectrum compared with the free ligand.展开更多
A novel coumarin Schiff base fluorescent probe ethyl 7-hydroxycoumarin-3-carboxylate-8-formaldehyde benzoyl hydrazone （EBH） has been designed and synthesized which shows solvent dependent dual sensing, viz., recogni...A novel coumarin Schiff base fluorescent probe ethyl 7-hydroxycoumarin-3-carboxylate-8-formaldehyde benzoyl hydrazone （EBH） has been designed and synthesized which shows solvent dependent dual sensing, viz., recognition of Ca^2＋ in DMF-H20 （9 ： 1, V/V） solution based on C=N isomerization, photoinduced electron transfer （PET） inhibition and chelation-enhanced fluorescence （CHEF） mechanism as well as detection of Zn^2＋ in HzO-CH3OH （9 ： 1, V/V） solution by excited-state intramolecular proton transfer （ESIPT） and CHEF processes. The structure of the probe EBH has been confirmed by single-crystal X-ray diffraction analysis. Meanwhile, the probe was also used to image intracellular Zn^2＋ ions in MCF-7 cells with a good performance.展开更多
Stable integration of hydrogel implants with host tissues is of critical importance to cartilage tissue engineering.Designing and fabricating hydrogels with high adhesive strength,stability and regeneration potential ...Stable integration of hydrogel implants with host tissues is of critical importance to cartilage tissue engineering.Designing and fabricating hydrogels with high adhesive strength,stability and regeneration potential are major challenges to be overcome.This study fabricated injectable adhesive hyaluronic acid(HA)hydrogel modified by aldehyde groups and methacrylate(AHAMA)on the polysaccharide backbone with multiple anchoring mechanisms(amide bond through the dynamic Schiff base reaction,hydrogen bond and physical interpenetration).AHAMA hydrogel exhibited significantly improved durability and stability within a humid environment(at least 7 days),together with higher adhesive strength(43 KPa to skin and 52 KPa to glass),as compared to commercial fibrin glue(nearly 10 KPa)and HAMA hydrogel(nearly 20 KPa).The results showed that AHAMA hydrogel was biocompatible and could be easily and rapidly prepared in situ.In vitro cell culture experiments showed that AHAMA hydrogel could enhance proliferation(1.2-folds after 3 days)and migration(1.5-folds after 12 h)of bone marrow stem cells(BMSCs),as compared to cells cultured in a culture dish.Furthermore,in a rat osteochondral defect model,implanted AHAMA hydrogel significantly promoted integration between neo-cartilage and host tissues,and significantly improved cartilage regeneration(modified O’Driscoll histological scores of 16.0±4.1 and 18.3±4.6 after 4 and 12-weeks of post-implantation in AHAMA groups respectively,12.0±2.7 and 12.2±2.8 respectively in HAMA groups,9.8±2.4 and 11.5±2.1 respectively in untreated groups).Hence,AHAMA hydrogel is a promising adhesive biomaterial for clinical cartilage regeneration and other biomedical applications.展开更多
Hydrophobic Val derivative Schiff base copper(II) complexes and dipeptide (AlaAla, GlyGly) derivative Schiff base copper(II) complexes were introduced into egg white lysozyme. X-ray crystal structure analysis revealed...Hydrophobic Val derivative Schiff base copper(II) complexes and dipeptide (AlaAla, GlyGly) derivative Schiff base copper(II) complexes were introduced into egg white lysozyme. X-ray crystal structure analysis revealed amino acid derivative Schiff base copper(II) complexes were obtained. Herein we discuss primarily on the binding mode of copper(II) of the complexes obtained with egg white lysozyme. The electron density of copper(II) ions was confirmed by X-ray crystal structure analysis. The Val derivative Schiff base copper(II) complex was weakly bound at Arg114 of egg white lysozyme. In other copper(II) complexes, binding of copper(II) ions with dissociated ligands to various residues was observed. The binding sites of copper(II) ions were compared with computational scientific predictions.展开更多
A new Ni（Ⅱ） cubane-like complex, namely, [Ni（L）（CH3OH）]4·（CH3OH）2, has been obtained via self-assembly of nickel（Ⅱ） and Schiff base, where the ligand L is a raceme of（R）-2-[（2-hydroxy-1-phenyl-ethy...A new Ni（Ⅱ） cubane-like complex, namely, [Ni（L）（CH3OH）]4·（CH3OH）2, has been obtained via self-assembly of nickel（Ⅱ） and Schiff base, where the ligand L is a raceme of（R）-2-[（2-hydroxy-1-phenyl-ethylimino）-methyl]-6-methoxy-phenol. X-ray diffraction analysis reveals that the complex shows a cubane-like [Ni4O4] cluster and similar coordination environment around the metallic centers. Magnetic measurements indicate there is ferromagnetic interaction within the Ni4 cluster.展开更多
Based on the existing reports on the bioactive isatin derivatives, a number of Schiff bases were synthesized by reacting 5-substituted isatins with bioactive amines/hydrazides and their structures were confirmed using...Based on the existing reports on the bioactive isatin derivatives, a number of Schiff bases were synthesized by reacting 5-substituted isatins with bioactive amines/hydrazides and their structures were confirmed using spectroscopic methods such as NMR, IR and mass spectrometry. Furthermore, Nbenzylation of isatin followed by the Schiff base formation furnished a new series of compounds（11a-13c） which allowed the analysis of the effect of isatin N-substitution on the bioactivity of the resulting compounds. The antibacterial activity of the synthesized derivatives was evaluated using a microtiter plate method on a series of gram positive and gram negative bacterial strains. Compounds 2d, 3b, 5c and 6a were among the most potent derivatives against Pseudomonas aeruginosa（MIC = 6.25 μg/m L）.Analysis of the structure-activity relationship showed that the incorporation of（thio）urea-based Schiff bases lead to more potent derivatives with a broader spectrum of antibacterial activity. In addition,highly lipophilic compounds such as 11a-12c did not show any measurable antibacterial activity, which implies that an optimal lipophilicity might be an important requirement for the antibacterial activity of the studied isatins. Finally, the finding that hydantoin derivatives of N-benzylisatins（13a-13c） still exhibit some antibacterial activity prompted us to consider exploring the bioactivity of more diverse derivatives of isatin-aminohydantoin Schiff bases（compounds 1a-1d） in our future studies.展开更多
p-Menthane type monoterpene derivatives were identified as bio-based compounds with high herbicidal activities. In order to search novel p-menthane type monoterpene derivatives in good performance, a series of novel c...p-Menthane type monoterpene derivatives were identified as bio-based compounds with high herbicidal activities. In order to search novel p-menthane type monoterpene derivatives in good performance, a series of novel cis-p-menthane type Schiff base derivatives were designed and synthesized. All target products were easily available novel compounds and characterized by FT-IR,^1H NMR,^13 C NMR and ESI＋-MS. Their pre-emergence herbicidal activities against annual ryegrass were evaluated. The bioassays indicated that most of the target compounds displayed excellent herbicidal activities in pre-emergence treatment.展开更多
A series of novel heteronuclear Ln( Ⅲ)-Cu( Ⅱ) complexes with noncyclic polyether-amino acid Schiff base were synthesized. The general formula is [LnCu2H2TALY)(NO3)5](NO3)2·nH2O (Ln= La, Nd, Sm, Gd, n = 4;Ln= Yb...A series of novel heteronuclear Ln( Ⅲ)-Cu( Ⅱ) complexes with noncyclic polyether-amino acid Schiff base were synthesized. The general formula is [LnCu2H2TALY)(NO3)5](NO3)2·nH2O (Ln= La, Nd, Sm, Gd, n = 4;Ln= Yb, Y, n = 3), where H2TALY = tetraglycol aldehyde bis-lysine Schiff base. It is the first time to report the synthetic method for this new Cu(Ⅱ) complexes and Ln( Ⅲ)-Cu( Ⅱ) heteronuclear complexes. The complexes were characterized by elemental analysis, IR spectra, TG-DTA, magnetic susceptibility, and especially by a 500 MHz NMR spectrometer for 2D-COSY NMR. Coordination mechanism and structures of complexes have been suggested as well. Of particular interest is the potential that the novel complexes obtained may be used as a catalyst, which prompted us to investigate them. It shows 100% conversion with the viscosity-average molecular weight 120 000 for the polymerization of methyl methacrylate (MMA) without addition of any cocatalyst. Furthermore, the complexes with such aliphatic Schiff bases can be used as a good catalyst, which has been confirmed and discussed here. They may be a new kind of catalyst system with the above speciality.展开更多
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 o...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<sup>−1</sup> while dominant wave occurred at ѵ1654.9 and ѵ1592.3 cm<sup>−1</sup> 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.展开更多
Fully conjugated Schiff base macrocycle has been prepared through a simple and mild condition,a one-pot cyclization procedure of four-component without using a template.The condensation reaction of related bis（hydrox...Fully conjugated Schiff base macrocycle has been prepared through a simple and mild condition,a one-pot cyclization procedure of four-component without using a template.The condensation reaction of related bis（hydroxybenzaldehyde） with phenylenediamines to prepare a conjugated[2 ＋ 2]Schiff base macrocycle has been investigated and fluorescent[2 ＋ 2]Schiff base macrocycles with N_2O_2 binding pockets has been prepared and characterized by elemental analysis,^1H NMR,IR,fluorescent,UV-visible and MALDI mass spectroscopies.展开更多
The title complex [Ni(TSSB)(phen)H2O]?C2H5OH?0.5H2O (C23H26N3NiO6.5S, TSSB = taurine salicylaldehyde Schiff base, phen = 1,10-phenanthroline) has been synthesized by the reaction of taurine salicylaldehyde Schiff base...The title complex [Ni(TSSB)(phen)H2O]?C2H5OH?0.5H2O (C23H26N3NiO6.5S, TSSB = taurine salicylaldehyde Schiff base, phen = 1,10-phenanthroline) has been synthesized by the reaction of taurine salicylaldehyde Schiff base (TSSB), 1,10-phenanthroline and nickel acetate in water-ethanol. Its single-crystal structure was determined by X-ray diffraction method. The crystal belongs to triclinic, space group P1 with a = 1.0562(2), b = 1.1604(2), c = 2.1170(3) nm, α = 103.257(3), β = 96.958(4), γ = 105.179(3)°, Mr = 539.24, V = 2.3917(6) nm3, Z = 4, Dc = 1.498 g/cm3, μ = 0.945 mm-1 and F(000) = 1124. The compound is a one-dimensional network, infinitely extending with hydrogen bonds. The Ni(Ⅱ) is 6-coordinated by one nitrogen and two oxygen atoms from taurine salicylaldehyde Schiff base, two nitrogen from 1,10-phenanthroline and one oxygen from water to form a distorted octahedronal coordination geometry.展开更多
Neodymium-based heterocyclic Schiff base complex was prepared and applied for the coordination polymerization of isoprene. This complex polymerized isoprene to afford products featuring high cis-1,4 stereospecificity ...Neodymium-based heterocyclic Schiff base complex was prepared and applied for the coordination polymerization of isoprene. This complex polymerized isoprene to afford products featuring high cis-1,4 stereospecificity （ca. 95%） and high molecular weight （ca, 10^5） in the presence of the triisobutyl aluminium （AliBu3） as cocatalyst, The microstructure of obtained polyisoprene was investigated by FTIR, 1^H NMR. Two different kinds of active centers in the catalyst system were examined by GPC method.展开更多
Seven new Schiff bases, which are 4,4,4-trifluo-ro-1-(2-thienyl)-1-butanone-3-Z, Z =-thioseraicarbazone (a); -thiocarbohydrazone (b),-benzoic hydrazone (c), -( o-hydroxyphenyl) imine (d) ,-nicotinic hydrazone (e),-sal...Seven new Schiff bases, which are 4,4,4-trifluo-ro-1-(2-thienyl)-1-butanone-3-Z, Z =-thioseraicarbazone (a); -thiocarbohydrazone (b),-benzoic hydrazone (c), -( o-hydroxyphenyl) imine (d) ,-nicotinic hydrazone (e),-salicylic hydrazone (f), and -(p-fluoro-m-chlorophenyl) imine (g), have been synthesized by reaction of 4, 4, 4-trifluoro-1-(2-thienyl)-1,3-butanedione (TFTBD) with corresponding hy-drazides or anilines, acetic acid or p-toluence sulfonic acid as catalyst, and characterized by Elemental analysis, IR, UV-Vis,1H NMR and MS. The MS spectra confirmed that the -C3=O condensed with primary amino group. Tauto-merism of the compounds is discussed.展开更多
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-methox...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.展开更多
A novel binuclear Cu（Ⅱ） complex [Cu（paba）Cl] （pabaH = 2-（2-pyridylmethylimine）benzenesulfonic acid） has been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. The c...A novel binuclear Cu（Ⅱ） complex [Cu（paba）Cl] （pabaH = 2-（2-pyridylmethylimine）benzenesulfonic acid） has been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. The crystal of the title complex crystallizes in a monoclinic system, space group P21/n, with a = 6.8165（7）, b = 15.3073（16）, c = 12.3795（13） A^°, β= 95.0160（10）°, V= 1286.8（2） A^°^3, Mr = 360.26, Dc= 1.860 g/cm^3,μ = 2.074 mm^-1, F（000） = 724, Z = 4, the final R = 0.0252 and wR = 0.0675 for 2395 observed reflections with I 〉 20（I）. The title complex is centrosymmetric and a pair of chlorides act as μ2-bridges to link two Cu（Ⅱ） ions forming a binuclear complex. Every Cu（Ⅱ） ion is five-coordinated by pyridyl N, imine N and sulfonate O atoms of the tridentate paba ligand as well as two bridging Cl^-, constructing the distorted square-pyramidal geometry. In the structure extensive hydrogen bonds and weak π-π stacking stabilize the solid structures, through which the complex builds its 3-dimensional supramolecular structure.展开更多
基金the National Natural Science Foundation of China (20671063)Shanghai Leading Academic Discipline Project (T0402)
文摘Five novel ternary complexes of the rare earth ions with o-phenanthroline（Phen） and Schiff base salicylaldehyde L-phenyla- lanine（KHL） were synthesized in ethanol. Their compositions were characterized by elemental analysis, molar conductance, ^1H NMR, FT-IR, and Raman spectra. The formulas of the complexes were verified to be RE（L）（Phen）Cl（H2O） （RE=La^3＋, Ce^3＋, Nd^3＋, Er^3＋, and Gd^3＋; L=Schiff base salicylaldehyde L-phenylalanine; phen=o-phenanthroline）. Methyl thiazolyl tetrazolium （MTT） colorimetry and flow cytometry were used to test the anticancer effect of the complexes with K562 tumor cell. The research showed that the complexes could inhibit K562 tumor cell＇s growth, generation, and induce apoptosis. The inhibition ratio was accelerated by increasing the dosage, and it had significant positive correlation with the medication dosage.
文摘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.
基金supported by the National Natural Science Foundation of China(Nos20872028 and 21072045)
文摘To further explore an efficient modified route for the shift from an antibacterial fluoroquinolone to an antitumor one,mono-Schiff bases 6a-6h related to ciprofloxacin C3 carbonylhydrazone and bis-Schiff bases 4a-4h corresponding to C3/C7 carbonylhydrazone/hydrazone attached on a skeleton of ciprofloquinolone were designed and synthesized,and their in vitro antitumor activity against CHO,HL60,L1210 cells and antibacterial activity against Staphylococcus aureus and Escherichia coli were also reported.
基金Project supported by the National Natural Science Foundation of China (Grant No. 29671026)the Natural Science Foundation of Zhejiang Province (Grant No. 296062)the Laboratory of MRAMP (Grant No. 971502)
文摘Owing to its two unsymmetrical-NH2 groups sited on different terminals, 2, 6-diaminocaproic acid (lysine) was used as a reactant for synthesizing a novel unsymmetrical Schiff base with salicylaldehyde on one side and ovanillin on the other for the first time. It is a new way to synthesize such a special unsymmetrical Schiff base. It is named “hetero bis-Schiff base” for distinguishing it from others. The synthesis method, formation mechanism as well as twelve new lanthaniHe complexes with the above ligand are reported and discussed herein. They were characterized by elementary analysis, molar conductivity, IR-spectra and especially by1H and13C NMR spectra. The results obtained may provide a new promising method for synthesizing similar unsymmetrical Schiff bases and their complexes.
基金Supported by the National Natural Science Foundation of China(21401024)Natural Science Foundation of Anhui Province(1508085MB21)+3 种基金Key Project of Natural Science Research in Universities of Anhui Province(KJ2016A550)Major Scientific and Technological Achievements Incubation Fund Project of Fuyang Normal College(kjfh201606)National Students Research Training Program(201510371013,201610371015)Doctoral Startup Foundation of Fuyang Normal College(FSB201501010)
文摘A pyridine-contained Schiff base ligand L（L =（pyridine-2-vinyl）hydrazine） has been synthesized and fully characterized. By self-assembly of the ligand with HgI2, a binuclear complex Hg2I4L（C） was obtained. The structures of L and C were analyzed through single-crystal X-ray diffraction. L crystallizes in monoclinic, space group P21/n with a=11.286（5）, b=3.981（5）, c=23.865（5） , β=100.043（5）°, V=1056（1） 3, Z=4, Dc=1.323 g/m3, F（000）=440, Μr=210.24, μ=0.084 mm（-1）, the final R=0.0928 and w R=0.2867 for 6955 observed reflections with I ＆gt; 2（I）. The complex is of monoclinic system, space group P21/n with a=8.706（5）, b=17.468（5）, c=14.675（5） , β=93.922（5）°, V=2227（2） 3, Z=4, Dc=3.338 g/m3, F（000）=1928, Μr=1119.02, μ=19.321 mm（-1）, the final R=0.0366 and w R=0.1276 for 3920 observed reflections with I ＆gt; 2（I）. The structural analysis revealed that the molecule of L possesses a well planar structure. However, in the complex, the coordinated ligand distorts greatly. The absorption spectra of L and the complex in ethanol were experimentally and theoretically studied. The result indicates that the complex exhibits different absorption spectrum compared with the free ligand.
基金Acknowledgement This work was supported by the National Natural Science Foundation of China （Nos. 21472148 and 21072158）, Overseas Students Science and Technology Activities Project Merit Funding of Shaanxi Province （No. 20151190） and Academic Backbone of Northwest University Outstanding Youth Support Program.
文摘A novel coumarin Schiff base fluorescent probe ethyl 7-hydroxycoumarin-3-carboxylate-8-formaldehyde benzoyl hydrazone （EBH） has been designed and synthesized which shows solvent dependent dual sensing, viz., recognition of Ca^2＋ in DMF-H20 （9 ： 1, V/V） solution based on C=N isomerization, photoinduced electron transfer （PET） inhibition and chelation-enhanced fluorescence （CHEF） mechanism as well as detection of Zn^2＋ in HzO-CH3OH （9 ： 1, V/V） solution by excited-state intramolecular proton transfer （ESIPT） and CHEF processes. The structure of the probe EBH has been confirmed by single-crystal X-ray diffraction analysis. Meanwhile, the probe was also used to image intracellular Zn^2＋ ions in MCF-7 cells with a good performance.
基金This work was supported by the National Natural Science Foundation of China grant(81772334)Peking University Medicine Seed Fund for Interdisciplinary Research(BMU2018ME001).
文摘Stable integration of hydrogel implants with host tissues is of critical importance to cartilage tissue engineering.Designing and fabricating hydrogels with high adhesive strength,stability and regeneration potential are major challenges to be overcome.This study fabricated injectable adhesive hyaluronic acid(HA)hydrogel modified by aldehyde groups and methacrylate(AHAMA)on the polysaccharide backbone with multiple anchoring mechanisms(amide bond through the dynamic Schiff base reaction,hydrogen bond and physical interpenetration).AHAMA hydrogel exhibited significantly improved durability and stability within a humid environment(at least 7 days),together with higher adhesive strength(43 KPa to skin and 52 KPa to glass),as compared to commercial fibrin glue(nearly 10 KPa)and HAMA hydrogel(nearly 20 KPa).The results showed that AHAMA hydrogel was biocompatible and could be easily and rapidly prepared in situ.In vitro cell culture experiments showed that AHAMA hydrogel could enhance proliferation(1.2-folds after 3 days)and migration(1.5-folds after 12 h)of bone marrow stem cells(BMSCs),as compared to cells cultured in a culture dish.Furthermore,in a rat osteochondral defect model,implanted AHAMA hydrogel significantly promoted integration between neo-cartilage and host tissues,and significantly improved cartilage regeneration(modified O’Driscoll histological scores of 16.0±4.1 and 18.3±4.6 after 4 and 12-weeks of post-implantation in AHAMA groups respectively,12.0±2.7 and 12.2±2.8 respectively in HAMA groups,9.8±2.4 and 11.5±2.1 respectively in untreated groups).Hence,AHAMA hydrogel is a promising adhesive biomaterial for clinical cartilage regeneration and other biomedical applications.
文摘Hydrophobic Val derivative Schiff base copper(II) complexes and dipeptide (AlaAla, GlyGly) derivative Schiff base copper(II) complexes were introduced into egg white lysozyme. X-ray crystal structure analysis revealed amino acid derivative Schiff base copper(II) complexes were obtained. Herein we discuss primarily on the binding mode of copper(II) of the complexes obtained with egg white lysozyme. The electron density of copper(II) ions was confirmed by X-ray crystal structure analysis. The Val derivative Schiff base copper(II) complex was weakly bound at Arg114 of egg white lysozyme. In other copper(II) complexes, binding of copper(II) ions with dissociated ligands to various residues was observed. The binding sites of copper(II) ions were compared with computational scientific predictions.
基金Supported by the National Natural Science Foundation of China(21101090 and 21561021)the Natural Science Foundation of Jiangxi Province(20114BAB213001)the Education Department of Jiangxi Province(GJJ12041)
文摘A new Ni（Ⅱ） cubane-like complex, namely, [Ni（L）（CH3OH）]4·（CH3OH）2, has been obtained via self-assembly of nickel（Ⅱ） and Schiff base, where the ligand L is a raceme of（R）-2-[（2-hydroxy-1-phenyl-ethylimino）-methyl]-6-methoxy-phenol. X-ray diffraction analysis reveals that the complex shows a cubane-like [Ni4O4] cluster and similar coordination environment around the metallic centers. Magnetic measurements indicate there is ferromagnetic interaction within the Ni4 cluster.
文摘Based on the existing reports on the bioactive isatin derivatives, a number of Schiff bases were synthesized by reacting 5-substituted isatins with bioactive amines/hydrazides and their structures were confirmed using spectroscopic methods such as NMR, IR and mass spectrometry. Furthermore, Nbenzylation of isatin followed by the Schiff base formation furnished a new series of compounds（11a-13c） which allowed the analysis of the effect of isatin N-substitution on the bioactivity of the resulting compounds. The antibacterial activity of the synthesized derivatives was evaluated using a microtiter plate method on a series of gram positive and gram negative bacterial strains. Compounds 2d, 3b, 5c and 6a were among the most potent derivatives against Pseudomonas aeruginosa（MIC = 6.25 μg/m L）.Analysis of the structure-activity relationship showed that the incorporation of（thio）urea-based Schiff bases lead to more potent derivatives with a broader spectrum of antibacterial activity. In addition,highly lipophilic compounds such as 11a-12c did not show any measurable antibacterial activity, which implies that an optimal lipophilicity might be an important requirement for the antibacterial activity of the studied isatins. Finally, the finding that hydantoin derivatives of N-benzylisatins（13a-13c） still exhibit some antibacterial activity prompted us to consider exploring the bioactivity of more diverse derivatives of isatin-aminohydantoin Schiff bases（compounds 1a-1d） in our future studies.
基金funded by the Key Projects in the National Science&Technology Pillar Program during the Twelfth Five-year Plan Period(No.2015BAD15B04)the National Natural Science Foundation of China(No.31600466)the Fundamental Research Funds for Jiangsu Key Laboratory of Biomass Energy and Material(No.JSBEM-S-201605)
文摘p-Menthane type monoterpene derivatives were identified as bio-based compounds with high herbicidal activities. In order to search novel p-menthane type monoterpene derivatives in good performance, a series of novel cis-p-menthane type Schiff base derivatives were designed and synthesized. All target products were easily available novel compounds and characterized by FT-IR,^1H NMR,^13 C NMR and ESI＋-MS. Their pre-emergence herbicidal activities against annual ryegrass were evaluated. The bioassays indicated that most of the target compounds displayed excellent herbicidal activities in pre-emergence treatment.
基金Project supported by the National Natural Science Foundation of China (Grant No. 29671026)Natural Science Foundation of Zhejiang Province (Grant No. 296062)the Laboratory of MRAMP (Grant No. 971502)
文摘A series of novel heteronuclear Ln( Ⅲ)-Cu( Ⅱ) complexes with noncyclic polyether-amino acid Schiff base were synthesized. The general formula is [LnCu2H2TALY)(NO3)5](NO3)2·nH2O (Ln= La, Nd, Sm, Gd, n = 4;Ln= Yb, Y, n = 3), where H2TALY = tetraglycol aldehyde bis-lysine Schiff base. It is the first time to report the synthetic method for this new Cu(Ⅱ) complexes and Ln( Ⅲ)-Cu( Ⅱ) heteronuclear complexes. The complexes were characterized by elemental analysis, IR spectra, TG-DTA, magnetic susceptibility, and especially by a 500 MHz NMR spectrometer for 2D-COSY NMR. Coordination mechanism and structures of complexes have been suggested as well. Of particular interest is the potential that the novel complexes obtained may be used as a catalyst, which prompted us to investigate them. It shows 100% conversion with the viscosity-average molecular weight 120 000 for the polymerization of methyl methacrylate (MMA) without addition of any cocatalyst. Furthermore, the complexes with such aliphatic Schiff bases can be used as a good catalyst, which has been confirmed and discussed here. They may be a new kind of catalyst system with the above speciality.
文摘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<sup>−1</sup> while dominant wave occurred at ѵ1654.9 and ѵ1592.3 cm<sup>−1</sup> 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.
基金sponsored by Isfahan University of technology(IUT)
文摘Fully conjugated Schiff base macrocycle has been prepared through a simple and mild condition,a one-pot cyclization procedure of four-component without using a template.The condensation reaction of related bis（hydroxybenzaldehyde） with phenylenediamines to prepare a conjugated[2 ＋ 2]Schiff base macrocycle has been investigated and fluorescent[2 ＋ 2]Schiff base macrocycles with N_2O_2 binding pockets has been prepared and characterized by elemental analysis,^1H NMR,IR,fluorescent,UV-visible and MALDI mass spectroscopies.
基金Supported by the NSF of Guangxi Province (No. 0339034), the Science Research Foundation of Guangxi Universities and Minister of Education Foundation of Guangxi (No. [2004]20)
文摘The title complex [Ni(TSSB)(phen)H2O]?C2H5OH?0.5H2O (C23H26N3NiO6.5S, TSSB = taurine salicylaldehyde Schiff base, phen = 1,10-phenanthroline) has been synthesized by the reaction of taurine salicylaldehyde Schiff base (TSSB), 1,10-phenanthroline and nickel acetate in water-ethanol. Its single-crystal structure was determined by X-ray diffraction method. The crystal belongs to triclinic, space group P1 with a = 1.0562(2), b = 1.1604(2), c = 2.1170(3) nm, α = 103.257(3), β = 96.958(4), γ = 105.179(3)°, Mr = 539.24, V = 2.3917(6) nm3, Z = 4, Dc = 1.498 g/cm3, μ = 0.945 mm-1 and F(000) = 1124. The compound is a one-dimensional network, infinitely extending with hydrogen bonds. The Ni(Ⅱ) is 6-coordinated by one nitrogen and two oxygen atoms from taurine salicylaldehyde Schiff base, two nitrogen from 1,10-phenanthroline and one oxygen from water to form a distorted octahedronal coordination geometry.
基金The authors are indebted to the financial supports of the National Natural Science Foundation of China （No.20774078 and the Key Program No.20434020）；the Special Funds for Major Basic Research Projects （G2005CB623802）.
文摘Neodymium-based heterocyclic Schiff base complex was prepared and applied for the coordination polymerization of isoprene. This complex polymerized isoprene to afford products featuring high cis-1,4 stereospecificity （ca. 95%） and high molecular weight （ca, 10^5） in the presence of the triisobutyl aluminium （AliBu3） as cocatalyst, The microstructure of obtained polyisoprene was investigated by FTIR, 1^H NMR. Two different kinds of active centers in the catalyst system were examined by GPC method.
文摘Seven new Schiff bases, which are 4,4,4-trifluo-ro-1-(2-thienyl)-1-butanone-3-Z, Z =-thioseraicarbazone (a); -thiocarbohydrazone (b),-benzoic hydrazone (c), -( o-hydroxyphenyl) imine (d) ,-nicotinic hydrazone (e),-salicylic hydrazone (f), and -(p-fluoro-m-chlorophenyl) imine (g), have been synthesized by reaction of 4, 4, 4-trifluoro-1-(2-thienyl)-1,3-butanedione (TFTBD) with corresponding hy-drazides or anilines, acetic acid or p-toluence sulfonic acid as catalyst, and characterized by Elemental analysis, IR, UV-Vis,1H NMR and MS. The MS spectra confirmed that the -C3=O condensed with primary amino group. Tauto-merism of the compounds is discussed.
文摘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.
基金funded by the Natural Science Foundation of Guangxi Province (No. 0731053)
文摘A novel binuclear Cu（Ⅱ） complex [Cu（paba）Cl] （pabaH = 2-（2-pyridylmethylimine）benzenesulfonic acid） has been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. The crystal of the title complex crystallizes in a monoclinic system, space group P21/n, with a = 6.8165（7）, b = 15.3073（16）, c = 12.3795（13） A^°, β= 95.0160（10）°, V= 1286.8（2） A^°^3, Mr = 360.26, Dc= 1.860 g/cm^3,μ = 2.074 mm^-1, F（000） = 724, Z = 4, the final R = 0.0252 and wR = 0.0675 for 2395 observed reflections with I 〉 20（I）. The title complex is centrosymmetric and a pair of chlorides act as μ2-bridges to link two Cu（Ⅱ） ions forming a binuclear complex. Every Cu（Ⅱ） ion is five-coordinated by pyridyl N, imine N and sulfonate O atoms of the tridentate paba ligand as well as two bridging Cl^-, constructing the distorted square-pyramidal geometry. In the structure extensive hydrogen bonds and weak π-π stacking stabilize the solid structures, through which the complex builds its 3-dimensional supramolecular structure.
