Raman spectra and ultraviolet-visible（UV-Vis） absorption spectra of linear polyene molecule-canthaxan-thin in n-hexane are measured and analyzed.In addition,the optimized structure of canthaxanthin was calculated vi...Raman spectra and ultraviolet-visible（UV-Vis） absorption spectra of linear polyene molecule-canthaxan-thin in n-hexane are measured and analyzed.In addition,the optimized structure of canthaxanthin was calculated via density functional theory（DFT） functional B3LYP.With decreasing the concentration,Raman scattering cross section （RSCS） of fundamental frequency is extremely high,and the UV-Vis absorption bands become narrower.The results of coherent weakly damped electron-Lattice vibration model were analyzed.展开更多
We theoretically and experimentally study the relationship between Fermi resonance and solvent effects and investigate the Fermi resonance of p-benzoquinone and cyclopentanone in different solvents and the Fermi reson...We theoretically and experimentally study the relationship between Fermi resonance and solvent effects and investigate the Fermi resonance of p-benzoquinone and cyclopentanone in different solvents and the Fermi resonance of CS_(2)in C_(6)H_(6)at different concentrations.Also,we investigate the Fermi resonance of C_(6)H_(6)and CCl_(4)in their solution at different pressures.It is found that solvent effects can be utilized to search Fermi resonance parameters such as coupling coefficient and spectral intensity ratio,etc.,on the other hand,the mechanism of solvent effects can be revealed according to Fermi resonance at high pressure.展开更多
We analyzed the properties and structures of the hydrogen-bonded complexes of tetrahydrofuran（THF） and water by means of experimental Raman spectra and ab initio calculations.The optimized geometries and vibrational...We analyzed the properties and structures of the hydrogen-bonded complexes of tetrahydrofuran（THF） and water by means of experimental Raman spectra and ab initio calculations.The optimized geometries and vibrational frequencies of the neat THF molecule and its hydrogen-bonded complexes with water（THF/H2O） were calculated at the MP2/6-311＋G（d,p） level of theory.We found that the intermolecular hydrogen bonds which are formed from the binary mixtures of the neat THF and water with different molar ratios could explain the changes in wavenumber position and linewidth very well.The combination of ab initio calculations and experimental Raman spectral data provides an insight into the hydrogen bonds leading to the concentration dependent changes in the spectral features.展开更多
We have determined the Raman scattering cross sections（RSCSs） of fl-carotene for C=C and C-C stretching modes, with the 1444 cm^-1 Raman band of cyclohexane as internal standard, in different solvents at low concent...We have determined the Raman scattering cross sections（RSCSs） of fl-carotene for C=C and C-C stretching modes, with the 1444 cm^-1 Raman band of cyclohexane as internal standard, in different solvents at low concentrations by measuring Raman intensity. The results show that RSCSs of β-carotene were 10^6-10^7 times larger than the general RSCSs, we analyzed that this enhancement was caused not only by the resonance Raman effect but also by nonlinear coherent CC vibration in aqueous β-carotene. Moreover, overtone and combinations of it were also observed and their intensities were 10%-20% of those of their fundamentals when β-carotene was dissolved in non-polar solvents, respectively.展开更多
基金Supported by the National Natural Science Foundation of China(No.10974067)the Natural Science Foundation of Jilin Province,China(No.20101508)the Technology Development Projects of Jilin Province,China(No.20090534)
文摘Raman spectra and ultraviolet-visible（UV-Vis） absorption spectra of linear polyene molecule-canthaxan-thin in n-hexane are measured and analyzed.In addition,the optimized structure of canthaxanthin was calculated via density functional theory（DFT） functional B3LYP.With decreasing the concentration,Raman scattering cross section （RSCS） of fundamental frequency is extremely high,and the UV-Vis absorption bands become narrower.The results of coherent weakly damped electron-Lattice vibration model were analyzed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10774057 and 10974067.
文摘We theoretically and experimentally study the relationship between Fermi resonance and solvent effects and investigate the Fermi resonance of p-benzoquinone and cyclopentanone in different solvents and the Fermi resonance of CS_(2)in C_(6)H_(6)at different concentrations.Also,we investigate the Fermi resonance of C_(6)H_(6)and CCl_(4)in their solution at different pressures.It is found that solvent effects can be utilized to search Fermi resonance parameters such as coupling coefficient and spectral intensity ratio,etc.,on the other hand,the mechanism of solvent effects can be revealed according to Fermi resonance at high pressure.
基金Supported by the National Natural Science Foundation of China(Nos.20303007,20333050,20973077)the Program for New Century Excellent Talents in University,China and the Graduate Innovation Fund of Jilin University,China(No.20101046)
文摘We analyzed the properties and structures of the hydrogen-bonded complexes of tetrahydrofuran（THF） and water by means of experimental Raman spectra and ab initio calculations.The optimized geometries and vibrational frequencies of the neat THF molecule and its hydrogen-bonded complexes with water（THF/H2O） were calculated at the MP2/6-311＋G（d,p） level of theory.We found that the intermolecular hydrogen bonds which are formed from the binary mixtures of the neat THF and water with different molar ratios could explain the changes in wavenumber position and linewidth very well.The combination of ab initio calculations and experimental Raman spectral data provides an insight into the hydrogen bonds leading to the concentration dependent changes in the spectral features.
基金Supported by the National Natural Science Foundation of China(No.10774057)the Foundation of Jilin Provincial Science & Technology Department,China(No.20090534)the Opened Fund of State Key Laboratory of Integrated Optoelectronics, China(No.IOSKL-KF200908)
文摘We have determined the Raman scattering cross sections（RSCSs） of fl-carotene for C=C and C-C stretching modes, with the 1444 cm^-1 Raman band of cyclohexane as internal standard, in different solvents at low concentrations by measuring Raman intensity. The results show that RSCSs of β-carotene were 10^6-10^7 times larger than the general RSCSs, we analyzed that this enhancement was caused not only by the resonance Raman effect but also by nonlinear coherent CC vibration in aqueous β-carotene. Moreover, overtone and combinations of it were also observed and their intensities were 10%-20% of those of their fundamentals when β-carotene was dissolved in non-polar solvents, respectively.
