The theoretical calculation and spectroscopic experiments indicate a kind of triangular three bonding supramolecular complexes CBr4…X^-…-H-C, which consist of carbon tetrabromide, halide, and protic solvent molecule...The theoretical calculation and spectroscopic experiments indicate a kind of triangular three bonding supramolecular complexes CBr4…X^-…-H-C, which consist of carbon tetrabromide, halide, and protic solvent molecule (referring to dichloromethane, chloroform and acetonitrile), can be formed in solution. The strength of halogen and hydrogen bonds in the triangular complexes using halide as common acceptor obeys the order of iodide〉bromide〉chloride. The halogen and hydrogen bonds work weak-cooperatively. Charge transfer bands of halogen bonding complexes between CBra and halide are observed in UV-Vis absorption spectroscopy in three solvents, and then the stoichiometry of 1:1, formation constants K and molar extinction coefficients ε of the halogen bonding complexes are obtained by Benesi-Hildebrand method. The K and ε show a dependence on the solvent dielectric constant and, on the whole, obey an order of iodide〉bromide〉chloride in the same solvents. Furthermore, the C-H vibrational frequencies of solvent molecules vary obviously with the addition of halide, which indicates the C-H…X- interaction. The experimental data indicate that the halogen bond and hydrogen bond coexist by sharing a common halide acceptor as predicted by calculation.展开更多
Spent silk worm pupae ofAntheraea assama were analyzed for its amino acid constituents and compared with the amino acid composition of fiber from A. assama, A. pyrni, and Bombyx mori. Amino acid percent was determined...Spent silk worm pupae ofAntheraea assama were analyzed for its amino acid constituents and compared with the amino acid composition of fiber from A. assama, A. pyrni, and Bombyx mori. Amino acid percent was determined by UV Spectrophotometer at 570 nm. Infra Red spectra recorded the presence of different amino acids in the spent silk worm pupae powder which corroborate with the amino acids present in the fiber of different silk species.展开更多
A novel acceptor material,9-(4′-(4,6-diphenyl-1,3,5-triazin-2-yl)-[1,1′-biphenyl]-3-yl)-9H-carbazole(o-DTPPC)was developed to form interface exciplex with commonly used donors,to maximize the performances of red pho...A novel acceptor material,9-(4′-(4,6-diphenyl-1,3,5-triazin-2-yl)-[1,1′-biphenyl]-3-yl)-9H-carbazole(o-DTPPC)was developed to form interface exciplex with commonly used donors,to maximize the performances of red phosphorescent organic light emitting diodes(PHOLEDs).It is found that the exciplex involving 4,4′-(cyclohexane-1,1-diyl)bis(N,N-di-p-tolylaniline)(TAPC)exhibits the most significant thermally activated delayed fluorescence(TADF)property,derived from the high triplet energy level as well as strong hole-transporting ability of TAPC.Intriguingly,it is the same donor-acceptor combination which achieved the highest device efficiency when adopted as the host for red PHOLEDs.Maximum efficiencies as high as31.36 cd A^(-1),17.95 lm W^(-1),and 21.01%for the current efficiency,power efficiency and external quantum efficiency,respectively with low efficiency roll-off were realized.The improved performance can be attributed to the efficient TADF properties of the interface exciplex-forming host constituting TAPC,benefiting the F?rster energy transfer.The article first underlines the importance of the constituting molecules in the interface exciplex-forming hosts,shedding new insight about the choice of interface exciplex as the host for PHOLEDs,which may lead to even higher performances,paving their ways towards practical applications.展开更多
Using heptane, toluene, and tetrahydrofuran (THF) as eluant, asphaltenes were fractionated into five fractions based on their polarity and solubility. The molecular composition of polar heteroatom species in both as...Using heptane, toluene, and tetrahydrofuran (THF) as eluant, asphaltenes were fractionated into five fractions based on their polarity and solubility. The molecular composition of polar heteroatom species in both asphaltene and its fractions were ana- lyzed by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). The application of UV-vis spectrometer in characterizing asphaltene composition and measuring asphaltene concentration was discussed. About 11.9 wt% asphaltene components adsorbed permanently on silica gel in the extrography column after exces- sive elution with various solvents. In negative FT-ICR MS, the mass spectra show that acidic and neutral nitrogen-containing compounds such as N1 and NIS1 mainly existe in the first three less polar fractions, while oxygen-containing compounds such as 02, O2S, O2S2, 03, and 04 show high relative abundance in more polar fractions. These results suggest oxygen-containing compounds have stronger adsorption ability with silica gel. It was observed that the double bond equivalence (DBE) distribu- tion of N1 class species in the fractions shifted to higher values while the carbon number shifted to smaller numbers as polarity of fractions increased. This indicates that acidic and neutral Nl compounds with longer carbon chain and less aromaticity have less polarity compared with those with shorter carbon chain and stronger aromaticity. UV-vis absorbance indicats that fractions containing the most aromatic and most polar asphaltene have better absorbance at long wavelength, while the fractions that consist of least aromatic and least polar asphatlenes show high absorbance at short wavelength.展开更多
Characteristic spectra in the 0.5-2.5 terahertz (THz) range of three commercial derv fuel oils have been obtained using THz time-domain spectroscopy and calculated using density functional theory.The simulated results...Characteristic spectra in the 0.5-2.5 terahertz (THz) range of three commercial derv fuel oils have been obtained using THz time-domain spectroscopy and calculated using density functional theory.The simulated results and experimental absorption curves suggest that the skeleton vibration is predominant in the THz region,and the absorption bumps of diesels are a superposition of various components.The investigation demonstrates that different diesels can be distinguished using THz time-domain spectroscopy and THz technology is a promising method to detect the composition and properties of diesels via chemical analysis.展开更多
As the necessary components for various modern electronic and optoelectronic devices, novel transparent electrodes(TEs) with the low cost, abundance features, and comparable performance of indium tin oxide(ITO) are in...As the necessary components for various modern electronic and optoelectronic devices, novel transparent electrodes(TEs) with the low cost, abundance features, and comparable performance of indium tin oxide(ITO) are inquired materials. Metal nanowires(NWs) with the excellent photoelectric properties as next-generation TE candidates have widely applications in smart optoelectronic devices such as electronic skins, wearable electronics, robotic skins, flexible and stretchable displays. This review describes the synthetic strategies for the preparation of metal NWs, the assemble process for metal NW films,and the practical aspects of metal NW films with the desired properties in various low-cost, flexible,and solution-based photoelectric devices.展开更多
Atomic energy is an important part of current energy resources.Production of nuclear weapons and applications of nuclear fuels in nuclear power plants have accumulated numerous spent fuels containing238U compounds,whi...Atomic energy is an important part of current energy resources.Production of nuclear weapons and applications of nuclear fuels in nuclear power plants have accumulated numerous spent fuels containing238U compounds,which are critical nuclear materials.How to reduce the nuclear wastes and to make use of the spent uranium are key scientific issues of environmental and nuclear science.We have reviewed here the physiochemical properties and photocatalytic mechanisms of homogeneous and heterogeneous uranium-containing materials.The current research efforts demonstrate that spent fuels can become promising new photocatalytic materials.展开更多
The design and construction of highly effective circularly polarized luminescence(CPL)-active materials has aroused considerable attention due to their widespread applications in sensors,optical devices,and asymmetric...The design and construction of highly effective circularly polarized luminescence(CPL)-active materials has aroused considerable attention due to their widespread applications in sensors,optical devices,and asymmetric synthesis.However,the exploration of novel CPL-active materials with high luminescence dissymmetry factor(glum)values is still a challenge.Herein,we describe a new approach for the preparation of supramolecular metallacycles with amplified CPL promoted by hierarchical self-assembly involving Pt···Pt interactions.Notably,the resultant metallacycles exhibited strong CPL signals with high glum values,while their corresponding precursors were CPL silent.The CPL amplification mechanism was comprehensively validated by ultravioletvisible absorption,emission spectroscopy,nuclear magnetic resonance spectroscopy,scanning electron microscopy,transmission electron microscopy,atomic force microscopy,coarse-grained molecular dynamics simulations,and timedependent density functional theory calculations.This work thus provides the first example of preparing highly effective CPL-active materials based on hierarchical self-assembly involving Pt···Pt interactions.展开更多
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.20675009 and No. 90922023). The basis set aug-cc-pVDZ-PP for iodine atom is downloaded at the website http://bse.pnl.gov/ bse/portal.
文摘The theoretical calculation and spectroscopic experiments indicate a kind of triangular three bonding supramolecular complexes CBr4…X^-…-H-C, which consist of carbon tetrabromide, halide, and protic solvent molecule (referring to dichloromethane, chloroform and acetonitrile), can be formed in solution. The strength of halogen and hydrogen bonds in the triangular complexes using halide as common acceptor obeys the order of iodide〉bromide〉chloride. The halogen and hydrogen bonds work weak-cooperatively. Charge transfer bands of halogen bonding complexes between CBra and halide are observed in UV-Vis absorption spectroscopy in three solvents, and then the stoichiometry of 1:1, formation constants K and molar extinction coefficients ε of the halogen bonding complexes are obtained by Benesi-Hildebrand method. The K and ε show a dependence on the solvent dielectric constant and, on the whole, obey an order of iodide〉bromide〉chloride in the same solvents. Furthermore, the C-H vibrational frequencies of solvent molecules vary obviously with the addition of halide, which indicates the C-H…X- interaction. The experimental data indicate that the halogen bond and hydrogen bond coexist by sharing a common halide acceptor as predicted by calculation.
文摘Spent silk worm pupae ofAntheraea assama were analyzed for its amino acid constituents and compared with the amino acid composition of fiber from A. assama, A. pyrni, and Bombyx mori. Amino acid percent was determined by UV Spectrophotometer at 570 nm. Infra Red spectra recorded the presence of different amino acids in the spent silk worm pupae powder which corroborate with the amino acids present in the fiber of different silk species.
基金supported by the National Key Basic Research and Development Program of China (2016YFB041003, 2016YFB0400702)the National Basic Research Program of China (2015CB655002)the National Natural Science Foundation of China (51525304, U1601651)
文摘A novel acceptor material,9-(4′-(4,6-diphenyl-1,3,5-triazin-2-yl)-[1,1′-biphenyl]-3-yl)-9H-carbazole(o-DTPPC)was developed to form interface exciplex with commonly used donors,to maximize the performances of red phosphorescent organic light emitting diodes(PHOLEDs).It is found that the exciplex involving 4,4′-(cyclohexane-1,1-diyl)bis(N,N-di-p-tolylaniline)(TAPC)exhibits the most significant thermally activated delayed fluorescence(TADF)property,derived from the high triplet energy level as well as strong hole-transporting ability of TAPC.Intriguingly,it is the same donor-acceptor combination which achieved the highest device efficiency when adopted as the host for red PHOLEDs.Maximum efficiencies as high as31.36 cd A^(-1),17.95 lm W^(-1),and 21.01%for the current efficiency,power efficiency and external quantum efficiency,respectively with low efficiency roll-off were realized.The improved performance can be attributed to the efficient TADF properties of the interface exciplex-forming host constituting TAPC,benefiting the F?rster energy transfer.The article first underlines the importance of the constituting molecules in the interface exciplex-forming hosts,shedding new insight about the choice of interface exciplex as the host for PHOLEDs,which may lead to even higher performances,paving their ways towards practical applications.
文摘Using heptane, toluene, and tetrahydrofuran (THF) as eluant, asphaltenes were fractionated into five fractions based on their polarity and solubility. The molecular composition of polar heteroatom species in both asphaltene and its fractions were ana- lyzed by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). The application of UV-vis spectrometer in characterizing asphaltene composition and measuring asphaltene concentration was discussed. About 11.9 wt% asphaltene components adsorbed permanently on silica gel in the extrography column after exces- sive elution with various solvents. In negative FT-ICR MS, the mass spectra show that acidic and neutral nitrogen-containing compounds such as N1 and NIS1 mainly existe in the first three less polar fractions, while oxygen-containing compounds such as 02, O2S, O2S2, 03, and 04 show high relative abundance in more polar fractions. These results suggest oxygen-containing compounds have stronger adsorption ability with silica gel. It was observed that the double bond equivalence (DBE) distribu- tion of N1 class species in the fractions shifted to higher values while the carbon number shifted to smaller numbers as polarity of fractions increased. This indicates that acidic and neutral Nl compounds with longer carbon chain and less aromaticity have less polarity compared with those with shorter carbon chain and stronger aromaticity. UV-vis absorbance indicats that fractions containing the most aromatic and most polar asphaltene have better absorbance at long wavelength, while the fractions that consist of least aromatic and least polar asphatlenes show high absorbance at short wavelength.
基金supported by the Program for New Century Excellent Talents in Universitythe National Natural Science Foundation of China+2 种基金the Research Fund for the Doctoral Program of Higher Educationthe State Key Laboratory of Heavy Oil Processing,China University of PetroleumForesight Fund Program from China University of Petroleum (Beijing)
文摘Characteristic spectra in the 0.5-2.5 terahertz (THz) range of three commercial derv fuel oils have been obtained using THz time-domain spectroscopy and calculated using density functional theory.The simulated results and experimental absorption curves suggest that the skeleton vibration is predominant in the THz region,and the absorption bumps of diesels are a superposition of various components.The investigation demonstrates that different diesels can be distinguished using THz time-domain spectroscopy and THz technology is a promising method to detect the composition and properties of diesels via chemical analysis.
基金supported by the National Basic Research Program of China(2014CB931700)the Fundamental Research Funds for the Central Universities(30920130111017 and NE2012004)+1 种基金the Opened Fund of the State Key Laboratory on Integrated Optoelectronics(IOSKL2012KF06)the Program for Eastern Scholar at Shanghai Institutions of Higher Learning(2012-53)
文摘As the necessary components for various modern electronic and optoelectronic devices, novel transparent electrodes(TEs) with the low cost, abundance features, and comparable performance of indium tin oxide(ITO) are inquired materials. Metal nanowires(NWs) with the excellent photoelectric properties as next-generation TE candidates have widely applications in smart optoelectronic devices such as electronic skins, wearable electronics, robotic skins, flexible and stretchable displays. This review describes the synthetic strategies for the preparation of metal NWs, the assemble process for metal NW films,and the practical aspects of metal NW films with the desired properties in various low-cost, flexible,and solution-based photoelectric devices.
基金supported by the National Basic Research Program of China(973 Project,2011CB932400)Strategic International Collaborative Research Program of China(SICORP,2013DFG50150)
文摘Atomic energy is an important part of current energy resources.Production of nuclear weapons and applications of nuclear fuels in nuclear power plants have accumulated numerous spent fuels containing238U compounds,which are critical nuclear materials.How to reduce the nuclear wastes and to make use of the spent uranium are key scientific issues of environmental and nuclear science.We have reviewed here the physiochemical properties and photocatalytic mechanisms of homogeneous and heterogeneous uranium-containing materials.The current research efforts demonstrate that spent fuels can become promising new photocatalytic materials.
基金supported by the National Natural Science Foundation of China(21922506,21871092,and 21603074)Shanghai Pujiang Program(18PJD015)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Austrian Science Fund(M 2709-N28)for the financial support。
文摘The design and construction of highly effective circularly polarized luminescence(CPL)-active materials has aroused considerable attention due to their widespread applications in sensors,optical devices,and asymmetric synthesis.However,the exploration of novel CPL-active materials with high luminescence dissymmetry factor(glum)values is still a challenge.Herein,we describe a new approach for the preparation of supramolecular metallacycles with amplified CPL promoted by hierarchical self-assembly involving Pt···Pt interactions.Notably,the resultant metallacycles exhibited strong CPL signals with high glum values,while their corresponding precursors were CPL silent.The CPL amplification mechanism was comprehensively validated by ultravioletvisible absorption,emission spectroscopy,nuclear magnetic resonance spectroscopy,scanning electron microscopy,transmission electron microscopy,atomic force microscopy,coarse-grained molecular dynamics simulations,and timedependent density functional theory calculations.This work thus provides the first example of preparing highly effective CPL-active materials based on hierarchical self-assembly involving Pt···Pt interactions.