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
In this study, our vibrational spectroscopic analysis is made on hydrogen-bonding between dimethyl sulfoxide and water comprises both experimental Raman spectra and ab initio calculations on structures of various dime...In this study, our vibrational spectroscopic analysis is made on hydrogen-bonding between dimethyl sulfoxide and water comprises both experimental Raman spectra and ab initio calculations on structures of various dimethyl sulfoxide/water clusters with increasing water content. The Raman peak position of the v（S=O） stretching mode of dimethyl sulfoxide serves as a probe for monitoring the degree of hydrogen-bonding between dimethyl sulfoxide and water. In addition, the two vibrational modes, namely, the CH3 symmetric stretching mode and the CH3 asymmetric stretching mode have been analysed under different concentrations. We relate the computational results to the experimental vibrational wavenumber trends that are observed in our concentration-dependent Raman study. The combination of experimental Raman data with ab initio calculation leads to a better knowledge of the nature of the hydrogen bonding and the structures of the hydrogen-bonded complexes studied.展开更多
The free radical of CICOCO has been investigated theoretically and experimentallyGeometry、vibrational frequencies and dissociative energy barrier of the ground state of CICOCOwere obtained by ab initio calculations. ...The free radical of CICOCO has been investigated theoretically and experimentallyGeometry、vibrational frequencies and dissociative energy barrier of the ground state of CICOCOwere obtained by ab initio calculations. By 351 nm photolysis of (CICO)2, CICOCO’s infraredendssion at 1844 cm-1 was recorded by TRFTIR spectrometer.展开更多
The ethoxycarbonyl isothiocyanate has been investigated by using supersonic jet Fourier transform microwave spectroscopy.Two sets of rotational spectra belonging to conformers TCC(with the backbone of C-C-O-C,C-O-C=O,...The ethoxycarbonyl isothiocyanate has been investigated by using supersonic jet Fourier transform microwave spectroscopy.Two sets of rotational spectra belonging to conformers TCC(with the backbone of C-C-O-C,C-O-C=O,and O-C(=O)-NCS being trans,cis,and cis arranged,respectively)and GCC(gauche,cis,and cis arrangement of the C-C-O-C,C-O-C=O,and O-C(=O)-NCS)have been measured and assigned.The measurements of13C,15N and34S mono-substituted species of the two conformers have also been performed.The comprehensive rotational spectroscopic investigations provide accurate values of rotational constants and14N quadrupole coupling constants,which lead to structural determinations of the two conformers of ethoxycarbonyl isothiocyanate.For conformer TCC,the values of Pcckeep constant upon isotopic substitution,indicating that the heavy atoms of TCC are effectively located in the ab plane.展开更多
The conformers of allyl alcohol and allyl mercaptan were studied with B3LYP/aug-cc-pVTZ method. Their relative energies were calculated at MP3, MP4（SDQ）, and CCSD（T） levels. The most stable conformers for these tw...The conformers of allyl alcohol and allyl mercaptan were studied with B3LYP/aug-cc-pVTZ method. Their relative energies were calculated at MP3, MP4（SDQ）, and CCSD（T） levels. The most stable conformers for these two molecules are Gauche-gauche＇ （Gg＇）. The theo-retical photoelectron spectra simulated with the calculated ionization energies demonstrate that there are at least four conformers in allyl alcohol and four conformers in allyl mercaptan in the gas-phase experiments. The Dyson orbitals of the highest occupied molecular orbital （HOMO） and the next HOMO （HOMO-1） of allyl mercaptan Ggt conformer show strongly mixing ns and πc=c characteristics, which may be due to the resonance and inductive effects between πc=c and ns in HOMO-1 and HOMO.展开更多
Since the discovery of the first drum-like CoB16- complex, metal-doped drum-like boron nanotubular structures have been investigated with various metal dopants and different tubular size, forming a new class of novel ...Since the discovery of the first drum-like CoB16- complex, metal-doped drum-like boron nanotubular structures have been investigated with various metal dopants and different tubular size, forming a new class of novel nanostructures. The CoB16- cluster was found to be composed of a central Co atom coordinated by two fused B8 rings in a tubular structure, representing the potential embryo of metal-filled boron nanotubes and providing opportunities to design one-dimensional metal-boron nanostructures. Here we report improved photoelectron spectroscopy and a more in-depth electronic structure analysis of CoB16-, providing further insight into the chemical bonding and stability of the drum-like doped boron tubular structures. Most interestingly, we find that the central Co atom has an unusually low oxidation state of ?1 and neutral CoB16 can be viewed as a charge transfer complex (Co-@BB16+), suggesting both covalent and electrostatic interactions between the dopant and the boron drum.展开更多
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Project supported by the National Natural Science Foundation of China (Grant Nos. 10774057 and 10974067)the Graduate Innovation Fund of Jilin University
文摘In this study, our vibrational spectroscopic analysis is made on hydrogen-bonding between dimethyl sulfoxide and water comprises both experimental Raman spectra and ab initio calculations on structures of various dimethyl sulfoxide/water clusters with increasing water content. The Raman peak position of the v（S=O） stretching mode of dimethyl sulfoxide serves as a probe for monitoring the degree of hydrogen-bonding between dimethyl sulfoxide and water. In addition, the two vibrational modes, namely, the CH3 symmetric stretching mode and the CH3 asymmetric stretching mode have been analysed under different concentrations. We relate the computational results to the experimental vibrational wavenumber trends that are observed in our concentration-dependent Raman study. The combination of experimental Raman data with ab initio calculation leads to a better knowledge of the nature of the hydrogen bonding and the structures of the hydrogen-bonded complexes studied.
文摘The free radical of CICOCO has been investigated theoretically and experimentallyGeometry、vibrational frequencies and dissociative energy barrier of the ground state of CICOCOwere obtained by ab initio calculations. By 351 nm photolysis of (CICO)2, CICOCO’s infraredendssion at 1844 cm-1 was recorded by TRFTIR spectrometer.
基金The support from the National Natural Science Foundation of China(No.22273009)Chongqing University。
文摘The ethoxycarbonyl isothiocyanate has been investigated by using supersonic jet Fourier transform microwave spectroscopy.Two sets of rotational spectra belonging to conformers TCC(with the backbone of C-C-O-C,C-O-C=O,and O-C(=O)-NCS being trans,cis,and cis arranged,respectively)and GCC(gauche,cis,and cis arrangement of the C-C-O-C,C-O-C=O,and O-C(=O)-NCS)have been measured and assigned.The measurements of13C,15N and34S mono-substituted species of the two conformers have also been performed.The comprehensive rotational spectroscopic investigations provide accurate values of rotational constants and14N quadrupole coupling constants,which lead to structural determinations of the two conformers of ethoxycarbonyl isothiocyanate.For conformer TCC,the values of Pcckeep constant upon isotopic substitution,indicating that the heavy atoms of TCC are effectively located in the ab plane.
文摘The conformers of allyl alcohol and allyl mercaptan were studied with B3LYP/aug-cc-pVTZ method. Their relative energies were calculated at MP3, MP4（SDQ）, and CCSD（T） levels. The most stable conformers for these two molecules are Gauche-gauche＇ （Gg＇）. The theo-retical photoelectron spectra simulated with the calculated ionization energies demonstrate that there are at least four conformers in allyl alcohol and four conformers in allyl mercaptan in the gas-phase experiments. The Dyson orbitals of the highest occupied molecular orbital （HOMO） and the next HOMO （HOMO-1） of allyl mercaptan Ggt conformer show strongly mixing ns and πc=c characteristics, which may be due to the resonance and inductive effects between πc=c and ns in HOMO-1 and HOMO.
基金supported by the National Natural Science Foundation of China (No.21590792, No.91426302, and No.21433005)supported by the U.S. National Science Foundation (CHE-1763380)
文摘Since the discovery of the first drum-like CoB16- complex, metal-doped drum-like boron nanotubular structures have been investigated with various metal dopants and different tubular size, forming a new class of novel nanostructures. The CoB16- cluster was found to be composed of a central Co atom coordinated by two fused B8 rings in a tubular structure, representing the potential embryo of metal-filled boron nanotubes and providing opportunities to design one-dimensional metal-boron nanostructures. Here we report improved photoelectron spectroscopy and a more in-depth electronic structure analysis of CoB16-, providing further insight into the chemical bonding and stability of the drum-like doped boron tubular structures. Most interestingly, we find that the central Co atom has an unusually low oxidation state of ?1 and neutral CoB16 can be viewed as a charge transfer complex (Co-@BB16+), suggesting both covalent and electrostatic interactions between the dopant and the boron drum.
