The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are a...The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are accelerated after it has been treated with nano-anatase TiO_2; the UV-Vis absorption spectrum of PSⅡ particles is increased; the red shift of fluorescence emission peak of PSⅡ is 2 nm; the peak intensity is decreased; the PSⅡ signal Ⅱs of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PSⅡ circular dichroism(CD) spectrum is similar to that of control. It is suggested that nano-anatase TiO_2 might bind to the PSⅡ reaction center complex and intensify the function of the PSⅡ electron donor, however, nano-anatase TiO_2 treatment does not change the configuration of the PSⅡ reaction center complex.展开更多
Benzyl 4 amino 5 mercapto 1,2,4 triazole reacted with aromatic acids in the presence of phosphorus oxychloride, yielding a series of new compounds, i.e. , 3 benzyl 6 aryl 1,2,4 triazolothiadiazoles, each of which has ...Benzyl 4 amino 5 mercapto 1,2,4 triazole reacted with aromatic acids in the presence of phosphorus oxychloride, yielding a series of new compounds, i.e. , 3 benzyl 6 aryl 1,2,4 triazolothiadiazoles, each of which has an active methylene at 3 position. The structures of all the title compounds were confirmed by elementary analysis, IR, 1H NMR and 13 C NMR spectra.展开更多
The electronic structure of semiconductor materials governs the law of electron motion,which profoundly affects the properties such as conductivity and photoelectric conversion.Photo-responsive single-molecule junctio...The electronic structure of semiconductor materials governs the law of electron motion,which profoundly affects the properties such as conductivity and photoelectric conversion.Photo-responsive single-molecule junction technology provides insights into the electronic structure of photogenerated substances at the molecular scale,enabling the characterization of dynamic processes such as charge separation and energy transfer.These processes involve the unique quantum state known as the "exciton".The electrical characterization technique based on single molecule break junction facilities direct measurement of the photoelectric response of molecules at nanometer and subnanometer scale.This study reviews recent research progress of exciton effects and the characterization of optoelectronic phenomena.The mechanisms of exciton effects in three key optoelectronic phenomena—photoconductivity,photovoltaic s,and photoluminescence—are discussed.Furthermore,advanced spectral characterization techniques applied to the in-situ monitoring of single-molecule optoelectronic devices are highlighted.These include Raman spectroscopy with various enhancements,inelastic electron tunneling spectroscopy,and ultrafast spectroscopy with high resolution.展开更多
Starting with y-butyrolactone, 4-amino-3-（3-hydroxypropyl）-1H-1,2,4-triazole-5-（4H） thione 1 was prepared, and cyclization of it with 4-phenylbromoacetophenone gave 6-（4-biphenylyl）- 3-（3-hydroxypropyl）-7H-1,2...Starting with y-butyrolactone, 4-amino-3-（3-hydroxypropyl）-1H-1,2,4-triazole-5-（4H） thione 1 was prepared, and cyclization of it with 4-phenylbromoacetophenone gave 6-（4-biphenylyl）- 3-（3-hydroxypropyl）-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine Ⅱ. The structures of Ⅰ and Ⅱ were determined by elemental analyses, IR, ^1H NMR, ^13C NMR, and X-ray diffraction. Crystal data for 1： C5H10N4OS, Mr = 174.23, monoclinic system, space group P21/c, a =8.4568（6）, b = 22.8905（16）, c = 9.2625（6） A, β= 114.172（1）°, V= 1635.82（19） A^3, F（000） = 736, Z= 8, Dc = 1.415 g/cm^3, 2 λ=0.71073 A,μ = 0.346 mm^-1 and the final R = 0.0603 for 2870 unique reflections with 1993 observed ones （I 〉 2σ（I）. Crystal data for Ⅱ： C19H18N4OS, Mr = 350.43, monoclinic system, space group P21/c, a = 6.7481（7）, b = 8.2647（8）, c = 30.075（3） A, β= 94.445（2）°, V= 1672.3（3） A3, F（000） = 736, Z = 4, Dc = 1.392 g/cm^3, λ=0.71073 A,μ= 0.209 mm^-1 and the final R = 0.0667 for 3000 unique reflections with 2534 observed ones （I 〉 2σ（I））. In the crystal of compound Ⅱ, the five-membered triazole ring and two benzene rings are coplanar, while the six-membered thiadiazine ring is slightly distorted, with an r.m.s deviation of 0.227（1） A. Some hydrogen bonding interactions are observed and π-π stacking interactions between adjacent molecules are found in the packing diagrams of the two compounds.展开更多
The title compound 3-phenyl-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was synthesized from acetophenone,triazole,phenylthioisocyanate and 1,2-dibromo-ethane by several step reactions. Its structure was...The title compound 3-phenyl-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was synthesized from acetophenone,triazole,phenylthioisocyanate and 1,2-dibromo-ethane by several step reactions. Its structure was identified by means of 1H NMR,MS and IR spectrometries. The single crystal structure of \{3-phenyl\}-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was determined by X-ray diffraction. The preliminary bioassays have shown that the title compound exhibits the weak activities of fungicide and plant growth regulator.展开更多
3-(2-Hydroxyphenyl)-6-(4-nitrophenyl)-7H-1,2,4-triazolo[3,4-b][1,3,4] thiadiazine, C 16H 11N 5O 3S, was prepared by the cyclization of 3-(2-hydroxyphenyl)-4-amino-5-mercapto-1,2,4-triazole with 2-bromo-4-nitro...3-(2-Hydroxyphenyl)-6-(4-nitrophenyl)-7H-1,2,4-triazolo[3,4-b][1,3,4] thiadiazine, C 16H 11N 5O 3S, was prepared by the cyclization of 3-(2-hydroxyphenyl)-4-amino-5-mercapto-1,2,4-triazole with 2-bromo-4-nitroacetophenone. The compound was characterized by means of elemental analysis, IR, 1H NMR, 13C NMR, mass spectrometry, and X-ray diffraction. The compound crystallizes in a monoclinic system with space group C c, a=2.1853(4) nm, b=2.1192(5) nm, c=1.3526(3) nm, β=95.21(2)°, V=6.238(2) nm3 , D calcd.=1.505 Mg/m3, Z=16, F(000)=2916, R 1=0.0501, wR 2=0.0427. A comparison between the crystal structures of 1,2,4-triazolo[3,4-b] [1,3,4] thiadiazine and 1,2,4-triazolo[3,4-b][1,3,4] thiadiazole was made in the structural view. A two-dimensional network is formed by hydrogen bonds and π-π stacking interactions.展开更多
The aim of this study was to investigate the effects of rare earth elements （REEs） in preventing Hg^2＋ pollution, using fish intestinal DNA in vitro and study the mechanism of the interactions between Hg^2＋ , La^3...The aim of this study was to investigate the effects of rare earth elements （REEs） in preventing Hg^2＋ pollution, using fish intestinal DNA in vitro and study the mechanism of the interactions between Hg^2＋ , La^3＋ , the mixture of La^3＋ and Hg^2＋ and DNA by spectroscopy. The interactions between Hg^2＋ , La^3＋ , the mixture of La^3＋ and Hg^2＋ and DNA from fish intestine in vitro was investigate by using absorption spectrum and fluorescence emission spectrum. Ultraviolet absorption spectra indicated that the addition of Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ to DNA generated obvious hypochromic effect. Meanwhile, the 205.2 nm peak of DNA blue and the 258.2 nm peak of DNA red shifted. The hypochromic effect and peak shift was caused by these ions in an order of Hg^2＋ 〉 Hg^2＋ ＋ La^3＋ 〉 La^3＋ . The fluorescence emission spectra showed that as the addition of Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ , the emission peak at about 416.2 nm of DNA did not obviously change, but the fluorescence intensity reduced gradually with the order in treatment was Hg^2＋ 〉 Hg^2＋ 〉 La^3＋ 〉 La^3＋ . Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ had 1.12, 0.58, and 0.81 binding sites to DNA, the fluorescence quenching of DNA caused by them all attributed to static quenching. The binding constants KA of binding sites were 3.82×10^4 and 4.22×10^2 L·mol^-1 ; 2.50×10^4 and 2.95×10^3 L·mol^-1 ; 3.05×10^4 and 1.00×10^3 L·mol^-1. The results showed that La^3＋ could relieve destruction caused by Hg^2＋ on the DNA structure.展开更多
The title compound C18H16N4O2S has been synthesized by the reaction of 4-amino-3-（4-ethoxyphenyl）-5-mercapto-1,2,4-triazole with phenoxyacetic acid in phospho- rus oxychloride, and characterized by IR, NMR spectra a...The title compound C18H16N4O2S has been synthesized by the reaction of 4-amino-3-（4-ethoxyphenyl）-5-mercapto-1,2,4-triazole with phenoxyacetic acid in phospho- rus oxychloride, and characterized by IR, NMR spectra and elemental analysis. Its structure was determined by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a = 1.4903（3）, b = 1.5230（2）, c = 0.9615（16） nm, Z = 4, V = 1.7769（5） nm^3, Dc = 1.317 g/cm^3, μ = 0.201 mm^-1, F（000） = 736, R = 0.0795 and wR = 0.2233. In the title compound, all rings are essentially planar.展开更多
The title compound 3-benzyl-6-trichloromethyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole I （C11HTC13N4S, Mr = 333.62） has been synthesized, and its structure was determined by elemental analyses, IR, ^1H NMR, ^13C NMR...The title compound 3-benzyl-6-trichloromethyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole I （C11HTC13N4S, Mr = 333.62） has been synthesized, and its structure was determined by elemental analyses, IR, ^1H NMR, ^13C NMR, and X-ray diffractions. The crystal is of triclinic, space group P1^-, with a = 5.898（3）, b = 10.510（4）, c = 11.580（5） A, α = 74.936（7）, β= 75.476（7）, γ = 79.647（7）°, V= 665.9（5）/A^3, F（000） = 336, Z= 2, Dc = 1.664 g/cm^3, 2 = 0.71073A, p = 0.834 mm^-1, the final R = 0.0605 and wR = 0.0900. The secondary bonding interactions （SBIs） S…N and π-π stacking interactions are found in the crystal structure and they link the molecules into a three-dimensional network.展开更多
Six first row transition metal complexes with 1,6-bis（2′-pyridyl）-2,5-dithiahexane（Py;S;）, namely, MnPy;S;Cl;（1）, FePy;S;Cl;（2）, Co Py;S;Cl（3）, CoPy;S;（SCN）;（4）, NiPy;S;（SCN）;（5） and NiPy;S;（N;）;...Six first row transition metal complexes with 1,6-bis（2′-pyridyl）-2,5-dithiahexane（Py;S;）, namely, MnPy;S;Cl;（1）, FePy;S;Cl;（2）, Co Py;S;Cl（3）, CoPy;S;（SCN）;（4）, NiPy;S;（SCN）;（5） and NiPy;S;（N;）;（6）, have been synthesized. A mixture of MCl;·x H;O（M = Mn, Co） in MeOH（FeCl;·4H;O in MeCN） and the stoichiometric amount of Py;S;was stirred for 4 h at room temperature, then these aiming products 1, 2 and 3 could be obtained by purification. A mixture of MPy;S;Cl;（M = Co, Ni） in MeOH and two equivalents of KSCN or NaN;was stirred for 4 h at room temperature. After that, complexes 4, 5 and 6 could be got by purifying. For 1, 2, 3, 4 and 5, the metal centers are hexa-coordinated in a similar distorted octahedral geometry and the crystal structures have the same space group Pbcn. The crystal structure of compound 6 belongs to monoclinic with space group P21/c. The coordinated atoms around M（Ⅱ） are two pyridyl N atoms(N（1） and N（2）), two thioether S atoms(S（1） and S（2）) and two chloride ions(Cl（1） and Cl（2）) in compounds 1, 2, and 3, but in 4, 5, and 6, two chloride ions(Cl（1） and Cl（2）) are replaced by another two N atoms from N;or NCS;.展开更多
The title compound, 1,4-dimethyl-2,5-di { [2′-（3-pyridylmethylaminoformyl）phenoxyl]- methyl}benzene perchlorate （C36H36Cl2N4O12, Mr = 787.59）, has been synthesized and structurally determined by single-crystal X-...The title compound, 1,4-dimethyl-2,5-di { [2′-（3-pyridylmethylaminoformyl）phenoxyl]- methyl}benzene perchlorate （C36H36Cl2N4O12, Mr = 787.59）, has been synthesized and structurally determined by single-crystal X-ray diffraction. The crystal crystallizes in the orthorhombic system, space group Pbca with a = 14.366（4）, b = 15.159（4）, c = 16.443（5）A, V = 3580.9（17）/A3 Z = 4, De = 1.461 g/cm^3, /t = 0.253 mm^-1, F（000） = 1640, R = 0.0618 and wR = 0.1525 for 1615 observed reflections （I 〉 2σ（I））. In the structure of the title compound, a two-dimensional supramolecular layer is formed via intermolecular hydrogen bonding interactions.展开更多
The production of metal nanoparticles(NPs)has risen in importance in recent decades.The green synthesis of silver NPs(AgNPs)occupies a prime position in this development,and AgNPs have been widely used in various biom...The production of metal nanoparticles(NPs)has risen in importance in recent decades.The green synthesis of silver NPs(AgNPs)occupies a prime position in this development,and AgNPs have been widely used in various biomedical,industrial,and therapeutic applications.In this study,research was performed using corn silk(CS)for the synthesis of AgNPs.The green-synthesized CS-AgNPs were analyzed using various spectroscopy methods.The metal NPs exhibited intense surface plasmon resonance peaks at different wavelengths with a specific peak at 461 nm,which confirmed the synthesis of AgNPs.Fourier-transform infrared spectroscopy was performed to confirm the participation of phytoactive biocomponents of CS extract in the reduction and stabilization of CSAgNPs.Scanning electron microscopy of CS-AgNPs revealed that the NPs had an irregular,roughly spherical shape.The size of CS-AgNPs was evaluated via dynamic light scattering,which showed that the CS-AgNPs were polydisperse in nature with an average size of 3.6–58.6 nm and an average mean size of 53 nm.The zeta potential of CS-AgNPs was–27.5 mV,indicating that CS-AgNPs are highly stable in colloidal form with a high negative potential.CS-AgNPs exhibited excellent and moderate antimicrobial activity against Gram-positive and Gram-negative bacteria.CS-AgNPs had excellent antioxidant activity using the DPPH method compared with the nitric oxide assay and also could perform photocatalytic degradation of cotton blue dye.Furthermore,CS-AgNPs protected plasmid DNA at 95℃from heat-based denaturation.Thus,green-synthesized CS-AgNPs had potential for prolific biomedical,industrial,and molecular biology applications of economic importance.展开更多
The use of nanoparticles in treating dreadful diseases like cancer is the emerging field of research in cancer therapy.In the present investigation,the green biosynthesis of silver nanoparticles(AgNPs)with aqueous fru...The use of nanoparticles in treating dreadful diseases like cancer is the emerging field of research in cancer therapy.In the present investigation,the green biosynthesis of silver nanoparticles(AgNPs)with aqueous fruit extract of Terminalia belarica has been carried out,and ultraviolet-visible spectroscopy(UV-Vis)analysis was done which revealed an intense surface plasmon resonance(SPR)band at 430 nm,thus confirming the formation of Tb-AgNPs.The AgNPs were further characterized by Fourier transform-infrared spectroscopy(FTIR),showing the reduction of silver nitrate into Tb-AgNPs by the reduction of different functional groups such as hydroxyl,phenols,stretch of aldehydes,alkenes and aromatics.Transmission electron microscopy(TEM)and diffraction light scattering(DLS)study showed that the nanoparticles were round in shape with an average size of 46.5 nm.The atomic force microscopy(AFM)analysis also revealed similar results to facilitate that the AgNPs were round in shape,and the size was calculated by Z-coloration method.Furthermore,the X-ray diffraction(XRD)data confirmed that Tb-AgNPs were crystalline with face centered cubic(fcc)structure and were very stable with-29.1 mV Zeta potential.Tb-AgNPs showed efficient free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl,hydrogen peroxide and nitric oxide.The 2,2-diphenyl-1-picrylhydrazyl(DPPH)method was the best among the three antioxidant methods with the half maximal inhibitory concentration(IC50)value of 47.25±0.17.Tb-AgNPs also showed superior and efficient antibacterial activity greater than the control antibiotic,and showed effective anti-proliferative and cytotoxic effect on human breast cancer cells with IC50 value of 73.18µg/mL.The biosynthesized Tb-AgNPs with multifunctional properties could be employed as a source for the exploration of novel therapeutic antioxidant,antibacterial and anticancer agent.展开更多
Green synthesis of silver nanoparticles(Ag NPs)by both ripe and unripe fruit extract was carried out by an important medicinal plant Tinospora cordifolia.The ripe and unripe fruit extract mediated bio-inspired Ag NPs ...Green synthesis of silver nanoparticles(Ag NPs)by both ripe and unripe fruit extract was carried out by an important medicinal plant Tinospora cordifolia.The ripe and unripe fruit extract mediated bio-inspired Ag NPs showed surface plasmon resonance(SPR)band at 431 and 421 nm respectively and confirmed the formation of Tc-Ag NPs.The functional groups of bioactive components of ripe and unripe fruits were identified which reduced silver nitrate to silver ions by Fourier-transform infrared spectroscopy(FTIR).The size distribution of biosynthesized Tc-Ag NPs of ripe and unripe was determined by particle size analyzer which revealed that the Z average of Tc-Ag NPs was around 30-35 nm±1 nm and 30-35.8 nm±1 nm with an Z average of 25.9 and 28.5 nm respectively.Tc-Ag NPs exhibited stability due to its high negative zeta potential for both ripe and unripe fruit extract mediated Tc-Ag NPs as of-27.2 and-24.6 mV.Tc-Ag NPs were used to evaluate the antibacterial,antioxidant and catalytic activities.The Tc-Ag NPs revealed good antimicrobial activity.Antibiotic erythromycin was used as a standard in the present study.The Tc-Ag NPs of both ripe and unrippen fruits disclosed greater free radical scavenging efficacy which proved to be potent antioxidant agents and also exhibited potential catalytic activity by converting 4 nitro-phenol to 4 amino phenols at rapid pace.It was concluded that the Tc-Ag NPs synthesized by ripe and unripe fruits almost showed similar results,and so both of them proved to have excellent multifunctional biomedical properties.展开更多
Recent investigations on green synthesis of silver nanoparticles(AgNPs)have been widely used in various therapeutic and industrial applications.So in the present study,AgNPs and PVP coated AgNPs were biosynthesized us...Recent investigations on green synthesis of silver nanoparticles(AgNPs)have been widely used in various therapeutic and industrial applications.So in the present study,AgNPs and PVP coated AgNPs were biosynthesized using fig fruit(Ficus carica)named as FF-AgNPs PVP-FF-AgNPs.The FF-AgNPs and PVP-FF-AgNPs revealed the surface Plasmon resonance band at 446 nm and 460 nm respectively.The FT-IR analysis of both nanoparticles reveals that different bioactive components of the fruit extract were actively involved in reduction of AgNPs.The SEM revealed that the particles are roughly spherical and irregular in shape and size,EDX analysis confirms the formation of complete reduction of silver to elemental silver.DLS studies also revealed similar results with both the nanoparticles are within the range of 10±5 nm to 35±5 nm.The zeta potential studies reveal negative potential values were as follows FF-AgNPs has-13.8 mV and PVP-FF-AgNPs has-17.1 mV.They also exhibit good antimicrobial activity.Another important application of these nanoparticles is dual detection of toxic chromium(VI)and photocatalytic dye degradation of cotton blue by H2O2 quenching and without quenching.It is concluded that,biosynthesized FF-AgNPs and PVP-FF-AgNPs have multiple applications of economic importance and environmental pollution.展开更多
This study was conducted to identify promising applications of green silver nanoparticles(AgNPs)prepared from a bark extract of Sweetinia mahagoni(Sm).The green synthesized Sm-AgNPs were characterized using various sp...This study was conducted to identify promising applications of green silver nanoparticles(AgNPs)prepared from a bark extract of Sweetinia mahagoni(Sm).The green synthesized Sm-AgNPs were characterized using various spectroscopy methods.AgNPs were first investigated using ultraviolet-visible spectroscopy,and the metal nanoparticles exhibited an intense surfaceplasmon resonance(SPR)peak at different wavelengths.The green synthesized Sm-AgNPs had an SPR peak at 430 nm,which confirms the formation of Sm-AgNPs.In addition,Fourier transform infrared(FTIR)spectroscopy was conducted to determine the bioactive compounds of bark extract that actively participate in the reduction of Sm-AgNPs,and the results revealed O−H stretching of free hydroxyl alcohol and phenols,N−H bonds of primary amines,S=O stretching of sulfoxide in aromatic groups,C−I stretching due to aliphatic iodo compounds,and C−Br stretching by halo compounds of the bark extract which might reduce and stabilize Sm-AgNPs.Scanning electron microscopy(SEM)and energy dispersive X-ray spectroscopy(EDS)results revealed that Sm-AgNPs were approximately irregular spheres.EDS results revealed the complete reduction of silver to elemental silver.The particle size analysis of Sm-AgNPs was conducted using dynamic light scattering(DLS),and the results revealed that Sm-AgNPs were polydisperse with an average size range from 35.8 to 47.8 nm,an average mean size of 41.3 nm,and a Z average of 37.7 nm.Sm-AgNPs had a negative zeta potential value of−19.0 mV,indicating that Sm-AgNPs were very stable in colloidal form.Further studies were carried out to demonstrate their usefulness in industrial and biomedical applications.In these studies,Sm-AgNPs exhibited a very good antibacterial activity against both Gram-negative and Gram-positive bacteria.In addition to regular assays,we also investigated important industrial applications such as the reduction of toxic hexavalent chromium to a nontoxic form and sensing of Hg2+ions.The results revealed that Sm-AgNPs had an excellent performance in biosensor applications such as sensing and detecting mercury at parts per million/parts per billion levels.In conclusion,green Sm-AgNPs are promising materials in therapeutic and industrial applications.展开更多
文摘The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are accelerated after it has been treated with nano-anatase TiO_2; the UV-Vis absorption spectrum of PSⅡ particles is increased; the red shift of fluorescence emission peak of PSⅡ is 2 nm; the peak intensity is decreased; the PSⅡ signal Ⅱs of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PSⅡ circular dichroism(CD) spectrum is similar to that of control. It is suggested that nano-anatase TiO_2 might bind to the PSⅡ reaction center complex and intensify the function of the PSⅡ electron donor, however, nano-anatase TiO_2 treatment does not change the configuration of the PSⅡ reaction center complex.
基金Supported by the National Natural Science Foundation of Chinathe University Backbone Teachers Foundation of theEducation Ministry of Chinaand Zhejiang Province Education Department
文摘Benzyl 4 amino 5 mercapto 1,2,4 triazole reacted with aromatic acids in the presence of phosphorus oxychloride, yielding a series of new compounds, i.e. , 3 benzyl 6 aryl 1,2,4 triazolothiadiazoles, each of which has an active methylene at 3 position. The structures of all the title compounds were confirmed by elementary analysis, IR, 1H NMR and 13 C NMR spectra.
基金Supported by the National Natural Science Foundation of China (Grant No. 10961023)National Natural Science Foundation of China for Young Scholars (Grant No. 11101232)+1 种基金Natural Science Foundation of Qinghai Province for Young Scholars (Grant No. 2011-Z-929Q)Scientific Research Innovation Program of Qinghai Normal University
文摘In the paper, we prove that all generalized cocktail-party graphs with order at least 23 are determined by their adjacency spectra.
基金financially supported by the Program of Higher-Level Talents of IMU(No.21300-5223748)the National Natural Science Foundation of China(Nos.22103065 and 21661024)
文摘The electronic structure of semiconductor materials governs the law of electron motion,which profoundly affects the properties such as conductivity and photoelectric conversion.Photo-responsive single-molecule junction technology provides insights into the electronic structure of photogenerated substances at the molecular scale,enabling the characterization of dynamic processes such as charge separation and energy transfer.These processes involve the unique quantum state known as the "exciton".The electrical characterization technique based on single molecule break junction facilities direct measurement of the photoelectric response of molecules at nanometer and subnanometer scale.This study reviews recent research progress of exciton effects and the characterization of optoelectronic phenomena.The mechanisms of exciton effects in three key optoelectronic phenomena—photoconductivity,photovoltaic s,and photoluminescence—are discussed.Furthermore,advanced spectral characterization techniques applied to the in-situ monitoring of single-molecule optoelectronic devices are highlighted.These include Raman spectroscopy with various enhancements,inelastic electron tunneling spectroscopy,and ultrafast spectroscopy with high resolution.
基金This work was supported by the Natural Science Foundation of Zhejiang Province (No. M203149)
文摘Starting with y-butyrolactone, 4-amino-3-（3-hydroxypropyl）-1H-1,2,4-triazole-5-（4H） thione 1 was prepared, and cyclization of it with 4-phenylbromoacetophenone gave 6-（4-biphenylyl）- 3-（3-hydroxypropyl）-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine Ⅱ. The structures of Ⅰ and Ⅱ were determined by elemental analyses, IR, ^1H NMR, ^13C NMR, and X-ray diffraction. Crystal data for 1： C5H10N4OS, Mr = 174.23, monoclinic system, space group P21/c, a =8.4568（6）, b = 22.8905（16）, c = 9.2625（6） A, β= 114.172（1）°, V= 1635.82（19） A^3, F（000） = 736, Z= 8, Dc = 1.415 g/cm^3, 2 λ=0.71073 A,μ = 0.346 mm^-1 and the final R = 0.0603 for 2870 unique reflections with 1993 observed ones （I 〉 2σ（I）. Crystal data for Ⅱ： C19H18N4OS, Mr = 350.43, monoclinic system, space group P21/c, a = 6.7481（7）, b = 8.2647（8）, c = 30.075（3） A, β= 94.445（2）°, V= 1672.3（3） A3, F（000） = 736, Z = 4, Dc = 1.392 g/cm^3, λ=0.71073 A,μ= 0.209 mm^-1 and the final R = 0.0667 for 3000 unique reflections with 2534 observed ones （I 〉 2σ（I））. In the crystal of compound Ⅱ, the five-membered triazole ring and two benzene rings are coplanar, while the six-membered thiadiazine ring is slightly distorted, with an r.m.s deviation of 0.227（1） A. Some hydrogen bonding interactions are observed and π-π stacking interactions between adjacent molecules are found in the packing diagrams of the two compounds.
文摘The title compound 3-phenyl-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was synthesized from acetophenone,triazole,phenylthioisocyanate and 1,2-dibromo-ethane by several step reactions. Its structure was identified by means of 1H NMR,MS and IR spectrometries. The single crystal structure of \{3-phenyl\}-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was determined by X-ray diffraction. The preliminary bioassays have shown that the title compound exhibits the weak activities of fungicide and plant growth regulator.
基金Supported by the Natural Science Foundation of Zhejiang Province(No. M2 0 314 9)
文摘3-(2-Hydroxyphenyl)-6-(4-nitrophenyl)-7H-1,2,4-triazolo[3,4-b][1,3,4] thiadiazine, C 16H 11N 5O 3S, was prepared by the cyclization of 3-(2-hydroxyphenyl)-4-amino-5-mercapto-1,2,4-triazole with 2-bromo-4-nitroacetophenone. The compound was characterized by means of elemental analysis, IR, 1H NMR, 13C NMR, mass spectrometry, and X-ray diffraction. The compound crystallizes in a monoclinic system with space group C c, a=2.1853(4) nm, b=2.1192(5) nm, c=1.3526(3) nm, β=95.21(2)°, V=6.238(2) nm3 , D calcd.=1.505 Mg/m3, Z=16, F(000)=2916, R 1=0.0501, wR 2=0.0427. A comparison between the crystal structures of 1,2,4-triazolo[3,4-b] [1,3,4] thiadiazine and 1,2,4-triazolo[3,4-b][1,3,4] thiadiazole was made in the structural view. A two-dimensional network is formed by hydrogen bonds and π-π stacking interactions.
基金Project supported by the National Natural Science Foundation of China (20671067)
文摘The aim of this study was to investigate the effects of rare earth elements （REEs） in preventing Hg^2＋ pollution, using fish intestinal DNA in vitro and study the mechanism of the interactions between Hg^2＋ , La^3＋ , the mixture of La^3＋ and Hg^2＋ and DNA by spectroscopy. The interactions between Hg^2＋ , La^3＋ , the mixture of La^3＋ and Hg^2＋ and DNA from fish intestine in vitro was investigate by using absorption spectrum and fluorescence emission spectrum. Ultraviolet absorption spectra indicated that the addition of Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ to DNA generated obvious hypochromic effect. Meanwhile, the 205.2 nm peak of DNA blue and the 258.2 nm peak of DNA red shifted. The hypochromic effect and peak shift was caused by these ions in an order of Hg^2＋ 〉 Hg^2＋ ＋ La^3＋ 〉 La^3＋ . The fluorescence emission spectra showed that as the addition of Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ , the emission peak at about 416.2 nm of DNA did not obviously change, but the fluorescence intensity reduced gradually with the order in treatment was Hg^2＋ 〉 Hg^2＋ 〉 La^3＋ 〉 La^3＋ . Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ had 1.12, 0.58, and 0.81 binding sites to DNA, the fluorescence quenching of DNA caused by them all attributed to static quenching. The binding constants KA of binding sites were 3.82×10^4 and 4.22×10^2 L·mol^-1 ; 2.50×10^4 and 2.95×10^3 L·mol^-1 ; 3.05×10^4 and 1.00×10^3 L·mol^-1. The results showed that La^3＋ could relieve destruction caused by Hg^2＋ on the DNA structure.
基金This work was supported by the Natural Science Foundation of Zhejiang Province (No. M203149)
文摘The title compound C18H16N4O2S has been synthesized by the reaction of 4-amino-3-（4-ethoxyphenyl）-5-mercapto-1,2,4-triazole with phenoxyacetic acid in phospho- rus oxychloride, and characterized by IR, NMR spectra and elemental analysis. Its structure was determined by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a = 1.4903（3）, b = 1.5230（2）, c = 0.9615（16） nm, Z = 4, V = 1.7769（5） nm^3, Dc = 1.317 g/cm^3, μ = 0.201 mm^-1, F（000） = 736, R = 0.0795 and wR = 0.2233. In the title compound, all rings are essentially planar.
基金supported by the Natural Science Foundation of Zhejiang Province (No. M203149)
文摘The title compound 3-benzyl-6-trichloromethyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole I （C11HTC13N4S, Mr = 333.62） has been synthesized, and its structure was determined by elemental analyses, IR, ^1H NMR, ^13C NMR, and X-ray diffractions. The crystal is of triclinic, space group P1^-, with a = 5.898（3）, b = 10.510（4）, c = 11.580（5） A, α = 74.936（7）, β= 75.476（7）, γ = 79.647（7）°, V= 665.9（5）/A^3, F（000） = 336, Z= 2, Dc = 1.664 g/cm^3, 2 = 0.71073A, p = 0.834 mm^-1, the final R = 0.0605 and wR = 0.0900. The secondary bonding interactions （SBIs） S…N and π-π stacking interactions are found in the crystal structure and they link the molecules into a three-dimensional network.
基金supported by the NNSFC(Nos.21231003 and 21203195)
文摘Six first row transition metal complexes with 1,6-bis（2′-pyridyl）-2,5-dithiahexane（Py;S;）, namely, MnPy;S;Cl;（1）, FePy;S;Cl;（2）, Co Py;S;Cl（3）, CoPy;S;（SCN）;（4）, NiPy;S;（SCN）;（5） and NiPy;S;（N;）;（6）, have been synthesized. A mixture of MCl;·x H;O（M = Mn, Co） in MeOH（FeCl;·4H;O in MeCN） and the stoichiometric amount of Py;S;was stirred for 4 h at room temperature, then these aiming products 1, 2 and 3 could be obtained by purification. A mixture of MPy;S;Cl;（M = Co, Ni） in MeOH and two equivalents of KSCN or NaN;was stirred for 4 h at room temperature. After that, complexes 4, 5 and 6 could be got by purifying. For 1, 2, 3, 4 and 5, the metal centers are hexa-coordinated in a similar distorted octahedral geometry and the crystal structures have the same space group Pbcn. The crystal structure of compound 6 belongs to monoclinic with space group P21/c. The coordinated atoms around M（Ⅱ） are two pyridyl N atoms(N（1） and N（2）), two thioether S atoms(S（1） and S（2）) and two chloride ions(Cl（1） and Cl（2）) in compounds 1, 2, and 3, but in 4, 5, and 6, two chloride ions(Cl（1） and Cl（2）) are replaced by another two N atoms from N;or NCS;.
基金supported by the National Natural Science Foundation of China (No. 20401008)
文摘The title compound, 1,4-dimethyl-2,5-di { [2′-（3-pyridylmethylaminoformyl）phenoxyl]- methyl}benzene perchlorate （C36H36Cl2N4O12, Mr = 787.59）, has been synthesized and structurally determined by single-crystal X-ray diffraction. The crystal crystallizes in the orthorhombic system, space group Pbca with a = 14.366（4）, b = 15.159（4）, c = 16.443（5）A, V = 3580.9（17）/A3 Z = 4, De = 1.461 g/cm^3, /t = 0.253 mm^-1, F（000） = 1640, R = 0.0618 and wR = 0.1525 for 1615 observed reflections （I 〉 2σ（I））. In the structure of the title compound, a two-dimensional supramolecular layer is formed via intermolecular hydrogen bonding interactions.
文摘The production of metal nanoparticles(NPs)has risen in importance in recent decades.The green synthesis of silver NPs(AgNPs)occupies a prime position in this development,and AgNPs have been widely used in various biomedical,industrial,and therapeutic applications.In this study,research was performed using corn silk(CS)for the synthesis of AgNPs.The green-synthesized CS-AgNPs were analyzed using various spectroscopy methods.The metal NPs exhibited intense surface plasmon resonance peaks at different wavelengths with a specific peak at 461 nm,which confirmed the synthesis of AgNPs.Fourier-transform infrared spectroscopy was performed to confirm the participation of phytoactive biocomponents of CS extract in the reduction and stabilization of CSAgNPs.Scanning electron microscopy of CS-AgNPs revealed that the NPs had an irregular,roughly spherical shape.The size of CS-AgNPs was evaluated via dynamic light scattering,which showed that the CS-AgNPs were polydisperse in nature with an average size of 3.6–58.6 nm and an average mean size of 53 nm.The zeta potential of CS-AgNPs was–27.5 mV,indicating that CS-AgNPs are highly stable in colloidal form with a high negative potential.CS-AgNPs exhibited excellent and moderate antimicrobial activity against Gram-positive and Gram-negative bacteria.CS-AgNPs had excellent antioxidant activity using the DPPH method compared with the nitric oxide assay and also could perform photocatalytic degradation of cotton blue dye.Furthermore,CS-AgNPs protected plasmid DNA at 95℃from heat-based denaturation.Thus,green-synthesized CS-AgNPs had potential for prolific biomedical,industrial,and molecular biology applications of economic importance.
文摘The use of nanoparticles in treating dreadful diseases like cancer is the emerging field of research in cancer therapy.In the present investigation,the green biosynthesis of silver nanoparticles(AgNPs)with aqueous fruit extract of Terminalia belarica has been carried out,and ultraviolet-visible spectroscopy(UV-Vis)analysis was done which revealed an intense surface plasmon resonance(SPR)band at 430 nm,thus confirming the formation of Tb-AgNPs.The AgNPs were further characterized by Fourier transform-infrared spectroscopy(FTIR),showing the reduction of silver nitrate into Tb-AgNPs by the reduction of different functional groups such as hydroxyl,phenols,stretch of aldehydes,alkenes and aromatics.Transmission electron microscopy(TEM)and diffraction light scattering(DLS)study showed that the nanoparticles were round in shape with an average size of 46.5 nm.The atomic force microscopy(AFM)analysis also revealed similar results to facilitate that the AgNPs were round in shape,and the size was calculated by Z-coloration method.Furthermore,the X-ray diffraction(XRD)data confirmed that Tb-AgNPs were crystalline with face centered cubic(fcc)structure and were very stable with-29.1 mV Zeta potential.Tb-AgNPs showed efficient free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl,hydrogen peroxide and nitric oxide.The 2,2-diphenyl-1-picrylhydrazyl(DPPH)method was the best among the three antioxidant methods with the half maximal inhibitory concentration(IC50)value of 47.25±0.17.Tb-AgNPs also showed superior and efficient antibacterial activity greater than the control antibiotic,and showed effective anti-proliferative and cytotoxic effect on human breast cancer cells with IC50 value of 73.18µg/mL.The biosynthesized Tb-AgNPs with multifunctional properties could be employed as a source for the exploration of novel therapeutic antioxidant,antibacterial and anticancer agent.
文摘Green synthesis of silver nanoparticles(Ag NPs)by both ripe and unripe fruit extract was carried out by an important medicinal plant Tinospora cordifolia.The ripe and unripe fruit extract mediated bio-inspired Ag NPs showed surface plasmon resonance(SPR)band at 431 and 421 nm respectively and confirmed the formation of Tc-Ag NPs.The functional groups of bioactive components of ripe and unripe fruits were identified which reduced silver nitrate to silver ions by Fourier-transform infrared spectroscopy(FTIR).The size distribution of biosynthesized Tc-Ag NPs of ripe and unripe was determined by particle size analyzer which revealed that the Z average of Tc-Ag NPs was around 30-35 nm±1 nm and 30-35.8 nm±1 nm with an Z average of 25.9 and 28.5 nm respectively.Tc-Ag NPs exhibited stability due to its high negative zeta potential for both ripe and unripe fruit extract mediated Tc-Ag NPs as of-27.2 and-24.6 mV.Tc-Ag NPs were used to evaluate the antibacterial,antioxidant and catalytic activities.The Tc-Ag NPs revealed good antimicrobial activity.Antibiotic erythromycin was used as a standard in the present study.The Tc-Ag NPs of both ripe and unrippen fruits disclosed greater free radical scavenging efficacy which proved to be potent antioxidant agents and also exhibited potential catalytic activity by converting 4 nitro-phenol to 4 amino phenols at rapid pace.It was concluded that the Tc-Ag NPs synthesized by ripe and unripe fruits almost showed similar results,and so both of them proved to have excellent multifunctional biomedical properties.
文摘Recent investigations on green synthesis of silver nanoparticles(AgNPs)have been widely used in various therapeutic and industrial applications.So in the present study,AgNPs and PVP coated AgNPs were biosynthesized using fig fruit(Ficus carica)named as FF-AgNPs PVP-FF-AgNPs.The FF-AgNPs and PVP-FF-AgNPs revealed the surface Plasmon resonance band at 446 nm and 460 nm respectively.The FT-IR analysis of both nanoparticles reveals that different bioactive components of the fruit extract were actively involved in reduction of AgNPs.The SEM revealed that the particles are roughly spherical and irregular in shape and size,EDX analysis confirms the formation of complete reduction of silver to elemental silver.DLS studies also revealed similar results with both the nanoparticles are within the range of 10±5 nm to 35±5 nm.The zeta potential studies reveal negative potential values were as follows FF-AgNPs has-13.8 mV and PVP-FF-AgNPs has-17.1 mV.They also exhibit good antimicrobial activity.Another important application of these nanoparticles is dual detection of toxic chromium(VI)and photocatalytic dye degradation of cotton blue by H2O2 quenching and without quenching.It is concluded that,biosynthesized FF-AgNPs and PVP-FF-AgNPs have multiple applications of economic importance and environmental pollution.
文摘This study was conducted to identify promising applications of green silver nanoparticles(AgNPs)prepared from a bark extract of Sweetinia mahagoni(Sm).The green synthesized Sm-AgNPs were characterized using various spectroscopy methods.AgNPs were first investigated using ultraviolet-visible spectroscopy,and the metal nanoparticles exhibited an intense surfaceplasmon resonance(SPR)peak at different wavelengths.The green synthesized Sm-AgNPs had an SPR peak at 430 nm,which confirms the formation of Sm-AgNPs.In addition,Fourier transform infrared(FTIR)spectroscopy was conducted to determine the bioactive compounds of bark extract that actively participate in the reduction of Sm-AgNPs,and the results revealed O−H stretching of free hydroxyl alcohol and phenols,N−H bonds of primary amines,S=O stretching of sulfoxide in aromatic groups,C−I stretching due to aliphatic iodo compounds,and C−Br stretching by halo compounds of the bark extract which might reduce and stabilize Sm-AgNPs.Scanning electron microscopy(SEM)and energy dispersive X-ray spectroscopy(EDS)results revealed that Sm-AgNPs were approximately irregular spheres.EDS results revealed the complete reduction of silver to elemental silver.The particle size analysis of Sm-AgNPs was conducted using dynamic light scattering(DLS),and the results revealed that Sm-AgNPs were polydisperse with an average size range from 35.8 to 47.8 nm,an average mean size of 41.3 nm,and a Z average of 37.7 nm.Sm-AgNPs had a negative zeta potential value of−19.0 mV,indicating that Sm-AgNPs were very stable in colloidal form.Further studies were carried out to demonstrate their usefulness in industrial and biomedical applications.In these studies,Sm-AgNPs exhibited a very good antibacterial activity against both Gram-negative and Gram-positive bacteria.In addition to regular assays,we also investigated important industrial applications such as the reduction of toxic hexavalent chromium to a nontoxic form and sensing of Hg2+ions.The results revealed that Sm-AgNPs had an excellent performance in biosensor applications such as sensing and detecting mercury at parts per million/parts per billion levels.In conclusion,green Sm-AgNPs are promising materials in therapeutic and industrial applications.
