电场作用下溴甲烷的光谱和解离特性（英文）
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摘要
采用了密度泛函理论(density functional theory,DFT),在6-311++G(d,p)基组水平上使用B3LYP方法研究外电场(0-0.05a.u.)对于溴甲烷分子的键长、能隙及解离势能面的影响.结果表明:外加电场的方向和大小对于分子结构和解离势能面均有显著的影响.随着负向外电场(Br-C键方向)从0增加到0.05a.u.,C-Br键的键长先减小后增大,C-H键的键长逐渐增加,分子能隙EG逐渐减小,C-Br键的str振动频率逐渐增加而IR振动频率逐渐减小.进一步计算发现:随着正向外电场(C-Br键方向)从0增加到0.03a.u.,溴甲烷分子的势能曲线有所降低,解离势垒逐渐减小.因此,可以通过外电场来控制CH_3Br分子的降解.
B3 LYP/6-311 + +g( d,p) method is adopted to optimize ground state structure of CH3 Br molecule. Bond length,energy gap and dissociation potential energy surface of CH3 Br molecule in external electric field( 0-0. 05 a. u.)are studied. It shows that direction and magnitude of applied electric field is of great significance to molecular structure and potential energy surface. With negative electric field( C-Br bond direction) increases from 0 to 0. 05 a. u.,bond length of C-Br bond decreases first and then increases. Bond length of C-H bond increases gradually. Molecular energy gap EG decreases gradually. Vibrational frequency of C-Br bond increases while IR vibration frequency decreases. It is found that potential energy of methyl bromide molecule decreases and dissociation barrier decreases,which indicating that CH3 Br molecule is easy to be excited and dissociated in external electric field.
B3 LYP/6-311 + +g( d,p) method is adopted to optimize ground state structure of CH3 Br molecule. Bond length,energy gap and dissociation potential energy surface of CH3 Br molecule in external electric field( 0-0. 05 a. u.)are studied. It shows that direction and magnitude of applied electric field is of great significance to molecular structure and potential energy surface. With negative electric field( C-Br bond direction) increases from 0 to 0. 05 a. u.,bond length of C-Br bond decreases first and then increases. Bond length of C-H bond increases gradually. Molecular energy gap EG decreases gradually. Vibrational frequency of C-Br bond increases while IR vibration frequency decreases. It is found that potential energy of methyl bromide molecule decreases and dissociation barrier decreases,which indicating that CH3 Br molecule is easy to be excited and dissociated in external electric field.
引文
[1]LIU Y Z,XIAO S R,ZHANG C Y.Calibration of velocity map imaging system and photodissociation dynamics of 1,4-C4H8Br Cl[J].Acta Phys Sin,2012,61:193301.
[2]LIU Y Z,XIAO S R,ZHANG C Y.Photolysis of 1-C4H9I and 2-C4H9I at 266 nm:Direct observation of the effect of branching on the photodissociation mechanism[J].Chem Phys Chem,2009,10:830-834.
[3]ZAHEDI M,HARRISON J A,NIBLER J W.Theoretical investigation of rotationally inelastic collisions of the methyl radical with helium[J].Chem Phys,1994,100:4043.
[4]CHANDLER D W,THOMAN J W,JANSSEN M H M,et al.Laser ionization spectroscopy of CD3 via the 3 pz 2A‘2 Rydberg state[J].Chem Phys Lett,1989,90:60-67.
[5]LIU Y Z,LONG J Y,QIN C C,et al.Ultrafast photodissociation dynamics of n-butyl iodide in the A-ban[J].At Mol Sci,2011,2:99-108.
[6]XU M,LINHU R F,LI Y F.Study on the physical properties of molecule Li F in external electric field[J].Acta Phys Sin,2012,9:093102.
[7]HUANG D H,WANG F H,ZHU H.Molecular structure and spectrum of aluminium nitride molecule under the external electric field[J].Acta Chimica Sinica,2008,13:1599-1603.
[8]YAN Y Z,LI H W.Dissipationless spin-Hall current contribution in the extrinsic spin-Hall effect[J].Chinese Phys B,2009,7:2981-2987.
[9]XU G L,XIE H X,YUAN W,et al.Properties of a Si2N molecule under an external electric field[J].Chinese Phys B,2012,21:053101.
[10]YAO D Y,XU G L,LIU X F,et al.Study of the excitation properties of the Si3O2cluster under an external electric field[J].Chinese Phys B,2011,20:0103101.
[11]XU G L,LIU X F,XIE H X,et al.Si3O cluster:Excited properties under external electric field and oxygen-deficient defect models[J].Chinese Phys B,2011,20:013101.
[12]ZHAO J L,LI Z W.Light-induced scattering in SBN:Cr crystal under external electric fields and its suppression[J].Chinese Phys,2004,9:1464-1467.
[13]LUO Y P,TIEN L G.Effect of vacancy defect on electrical properties of chiral single-walled carbon nanotube under external electricaleld[J].Chinese Phys B,2001,1:017302.
[14]XU G L,LIU X F.Si2O2molecule:Structure of ground state and the excited properties under different external electricelds[J].Chinese Phys B,2010,11:113101.
[15]WANG D S,KIM M S,CHOE J C.Anisotropic photodissociation of CH3Cl+[J].Chem Phys,2001,115:5454.
[16]BUTLER J H,BATTLE M,BENDER M L.A record of atmospheric halocarbons during the twentieth century from polar firn air[J].Nature,1999,399:749-755.
[17]ZHENG G G,XIE A G,XU L H.Point imaging through one-dimensional graded metal-dielectric photonic crystals[J].Optik,2015,126:400-402.
[18]PENDRY J B.Negative refraction makes a perfect lens[J].Phys Rev Lett,2000,85:3966-3969.
[19]CHENG Q Y,LIU Y Z,LI J,et al.Molecular structure and spectrum of CCl3F under strong electric fields[J].Chinese Journal of Computational Physics,2017,34:489-494.
[20]YUAN D,HUANG D H,YANG J S.First-principles study of electronic structure and optical properties of Ag,S codoped Al N[J].Chinese Journal of Computational Physics,2017,34:475-482.
[21]HE M C,HU X X,ZHAO J.First-principles study of carbon monoxide adsorption liability on graphite(001)[J].Chinese Journal of Computational Physics,2016,33:737-742.
[22]FRISCH J,TRUCKS G W,SCHLEGEL H B.Gaussian 09,revision D.01[M].Gaussian,Inc Wallingford C T,2009.
[23]GUILLERMO D C P,PAUL S B,CHARLES W.Ab initio SCF MO calculations on the CH3Br molecule[J].Chim Acta(Berl),1977,45:121-126.
[24]SHIMANOUCHI T.“Molecular vibrational frequencies”[EB/OL]∥NIST chemistry web Book,NIST standard reference database Number 69,Linstrom P J,Mallard W G.Eds.National Institute of Standards and Technology,Gaithersburg MD,20899,http://webbook.nist.gov.
[2]LIU Y Z,XIAO S R,ZHANG C Y.Photolysis of 1-C4H9I and 2-C4H9I at 266 nm:Direct observation of the effect of branching on the photodissociation mechanism[J].Chem Phys Chem,2009,10:830-834.
[3]ZAHEDI M,HARRISON J A,NIBLER J W.Theoretical investigation of rotationally inelastic collisions of the methyl radical with helium[J].Chem Phys,1994,100:4043.
[4]CHANDLER D W,THOMAN J W,JANSSEN M H M,et al.Laser ionization spectroscopy of CD3 via the 3 pz 2A‘2 Rydberg state[J].Chem Phys Lett,1989,90:60-67.
[5]LIU Y Z,LONG J Y,QIN C C,et al.Ultrafast photodissociation dynamics of n-butyl iodide in the A-ban[J].At Mol Sci,2011,2:99-108.
[6]XU M,LINHU R F,LI Y F.Study on the physical properties of molecule Li F in external electric field[J].Acta Phys Sin,2012,9:093102.
[7]HUANG D H,WANG F H,ZHU H.Molecular structure and spectrum of aluminium nitride molecule under the external electric field[J].Acta Chimica Sinica,2008,13:1599-1603.
[8]YAN Y Z,LI H W.Dissipationless spin-Hall current contribution in the extrinsic spin-Hall effect[J].Chinese Phys B,2009,7:2981-2987.
[9]XU G L,XIE H X,YUAN W,et al.Properties of a Si2N molecule under an external electric field[J].Chinese Phys B,2012,21:053101.
[10]YAO D Y,XU G L,LIU X F,et al.Study of the excitation properties of the Si3O2cluster under an external electric field[J].Chinese Phys B,2011,20:0103101.
[11]XU G L,LIU X F,XIE H X,et al.Si3O cluster:Excited properties under external electric field and oxygen-deficient defect models[J].Chinese Phys B,2011,20:013101.
[12]ZHAO J L,LI Z W.Light-induced scattering in SBN:Cr crystal under external electric fields and its suppression[J].Chinese Phys,2004,9:1464-1467.
[13]LUO Y P,TIEN L G.Effect of vacancy defect on electrical properties of chiral single-walled carbon nanotube under external electricaleld[J].Chinese Phys B,2001,1:017302.
[14]XU G L,LIU X F.Si2O2molecule:Structure of ground state and the excited properties under different external electricelds[J].Chinese Phys B,2010,11:113101.
[15]WANG D S,KIM M S,CHOE J C.Anisotropic photodissociation of CH3Cl+[J].Chem Phys,2001,115:5454.
[16]BUTLER J H,BATTLE M,BENDER M L.A record of atmospheric halocarbons during the twentieth century from polar firn air[J].Nature,1999,399:749-755.
[17]ZHENG G G,XIE A G,XU L H.Point imaging through one-dimensional graded metal-dielectric photonic crystals[J].Optik,2015,126:400-402.
[18]PENDRY J B.Negative refraction makes a perfect lens[J].Phys Rev Lett,2000,85:3966-3969.
[19]CHENG Q Y,LIU Y Z,LI J,et al.Molecular structure and spectrum of CCl3F under strong electric fields[J].Chinese Journal of Computational Physics,2017,34:489-494.
[20]YUAN D,HUANG D H,YANG J S.First-principles study of electronic structure and optical properties of Ag,S codoped Al N[J].Chinese Journal of Computational Physics,2017,34:475-482.
[21]HE M C,HU X X,ZHAO J.First-principles study of carbon monoxide adsorption liability on graphite(001)[J].Chinese Journal of Computational Physics,2016,33:737-742.
[22]FRISCH J,TRUCKS G W,SCHLEGEL H B.Gaussian 09,revision D.01[M].Gaussian,Inc Wallingford C T,2009.
[23]GUILLERMO D C P,PAUL S B,CHARLES W.Ab initio SCF MO calculations on the CH3Br molecule[J].Chim Acta(Berl),1977,45:121-126.
[24]SHIMANOUCHI T.“Molecular vibrational frequencies”[EB/OL]∥NIST chemistry web Book,NIST standard reference database Number 69,Linstrom P J,Mallard W G.Eds.National Institute of Standards and Technology,Gaithersburg MD,20899,http://webbook.nist.gov.