The high resolution rotational spectrum of 2-(triuoromethyl)pyridine in 2-20 GHz was recorded and analyzed.Spectroscopic parameters including rotational constants,nuclear quadrupole coupling constants of 14N as well a...The high resolution rotational spectrum of 2-(triuoromethyl)pyridine in 2-20 GHz was recorded and analyzed.Spectroscopic parameters including rotational constants,nuclear quadrupole coupling constants of 14N as well as the centrifugal distortion constants were determined.The rotational spectra of ve mono-substituted 13C and one 15N isotopologues were also measured and assigned in natural abundance.Experimental results complemented by ab initio calculations lead to an accurate determination of the skeleton structure.The values of the planar moment inertia Pcc were determined to be 44.46 uA^2 for all the measured isotopologues,indicating a Cs symmetry of this molecule.The molecular electrostatic surface potential was calculated to illustrate the triuoromethyl substitution e ects on the electron distribution.展开更多
The molecular structures of three ethylanilines,ortho-,meta-and para-ethylaniline,have been obtained by means of Fourier-transform microwave spectroscopy.Rotational spectra of all three molecules display the nuclear q...The molecular structures of three ethylanilines,ortho-,meta-and para-ethylaniline,have been obtained by means of Fourier-transform microwave spectroscopy.Rotational spectra of all three molecules display the nuclear quadrupole hyperfine structures arising from the 14N nucleus.Comparison of the determined structures allows a direct study of the influence of the position of the ethyl substituent on the structure of the amino group communicated through the phenyl ring.展开更多
The ground state rotational spectrum of 2,3,6-trifluoropyridine has been investigated in the 2.0-20.0 GHz region by pulsed jet Fourier transform microwave spectroscopy.The experimental rotational constants are A=3134....The ground state rotational spectrum of 2,3,6-trifluoropyridine has been investigated in the 2.0-20.0 GHz region by pulsed jet Fourier transform microwave spectroscopy.The experimental rotational constants are A=3134.4479(2)MHz,B=1346.79372(7)MHz,and C=941.99495(6)MHz.The transitions are so intense that rotational transitions of all mono13C and 15N isotopologues are measured in natural abundance.The semi-experimental equilibrium rotational constants of the 7 isotopologues were derived by taking account of the anharmonic vibrational corrections,which allowed a semi-experimental determination of the equilibrium structure of 2,3,6-trifluoropyridine.展开更多
基金the National Natural Science Foundation of China(No.21703021 and No.U1931104)Chongqing University under the program of the Foundation of 100 Young,Fundamental and Frontier Research Fund of Chongqing(No.cstc2017jcyjAX0068 and No.cstc2018jcyjAX0050)Venture&Innovation Support Program for Chongqing Overseas Returns(No.cx2018064).
文摘The high resolution rotational spectrum of 2-(triuoromethyl)pyridine in 2-20 GHz was recorded and analyzed.Spectroscopic parameters including rotational constants,nuclear quadrupole coupling constants of 14N as well as the centrifugal distortion constants were determined.The rotational spectra of ve mono-substituted 13C and one 15N isotopologues were also measured and assigned in natural abundance.Experimental results complemented by ab initio calculations lead to an accurate determination of the skeleton structure.The values of the planar moment inertia Pcc were determined to be 44.46 uA^2 for all the measured isotopologues,indicating a Cs symmetry of this molecule.The molecular electrostatic surface potential was calculated to illustrate the triuoromethyl substitution e ects on the electron distribution.
基金Chongqing University under the Program of the Foundation of 100 Young,the Fundamental Research Funds for the Central Universities(No.2018CDQYHG0009)the National Natural Science Foundation of China(No.21703021 and No.U1931104)+1 种基金the Natural Science Foundation of Chongqing,China(No.cstc2017jcyjAX0068 and No.cstc2018jcyjAX0050)Venture&Innovation Support Program for Chongqing Oversea Returns(No.cx2018064).Juan Wang also thanks the China Scholarship Council(CSC)for the financial support.The Deutsche Forschungsgemeinschaft(DFG)and the Land Niedersachsen aided the work in Hannover.
文摘The molecular structures of three ethylanilines,ortho-,meta-and para-ethylaniline,have been obtained by means of Fourier-transform microwave spectroscopy.Rotational spectra of all three molecules display the nuclear quadrupole hyperfine structures arising from the 14N nucleus.Comparison of the determined structures allows a direct study of the influence of the position of the ethyl substituent on the structure of the amino group communicated through the phenyl ring.
基金the National Natural Science Foundation of China(No.21703021 and No.U1931104)the Natural Science Foundation of Chongqing,China(No.cstc2017jcyjAX0068 and No.cstc2018jcyjAX0050)+2 种基金Venture&Innovation Support Program for Chongqing Overseas Returns(No.cx2018064)Foundation of 100 Young Chongqing University(No.0220001104428)Fundamental Research Funds for the Central Universities(No.106112017CDJQJ228807 and No.2018CDQYHG0009).
文摘The ground state rotational spectrum of 2,3,6-trifluoropyridine has been investigated in the 2.0-20.0 GHz region by pulsed jet Fourier transform microwave spectroscopy.The experimental rotational constants are A=3134.4479(2)MHz,B=1346.79372(7)MHz,and C=941.99495(6)MHz.The transitions are so intense that rotational transitions of all mono13C and 15N isotopologues are measured in natural abundance.The semi-experimental equilibrium rotational constants of the 7 isotopologues were derived by taking account of the anharmonic vibrational corrections,which allowed a semi-experimental determination of the equilibrium structure of 2,3,6-trifluoropyridine.
