高振动激发态DBr(X~1Σ~+,v″=8、7)与 D_2,Ar间的碰撞振动能量转移
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摘要
利用YAG激光器泵浦OPO激光简并受激超拉曼泵浦DBr分子至基电子态的高振动态v″=8、7,研究高振动态DBr分子与其他碰撞气体(Ar、D_2)的碰撞弛豫过程.对于DBr(v″=8)和Ar、D_2混合体系,由高分辨瞬时激光感应荧光光谱方法探测碰撞弛豫后DBr分子振动态v″=8的时间分辨布居数的演化过程.保持总压强不变,改变碰撞气体的摩尔配比,测量相应条件下的有效寿命,由混合气体系统中Stern-Volmer公式,得到DBr(v″=8)分子与Ar、D_2的碰撞弛豫速率系数分别为k_8(Ar)=(0.51±0.1)×10~(-12 ) cm~3molecule~(-1)s~(-1),k_8(D_2)=(3.50±0.8)×10~(-12) cm~(3 )molecule~(-1 )s~(-1);DBr(v″=8)分子的平均自弛豫速率系数为k_8(DBr)=(1.20±0.4)×10~(-12) cm~3molecule~(-1)s~(-1).对于摩尔配比为0.5的DBr和D_2混合体系,Ti宝石激光器分别双光子激发DBr v″≤8、7各振动态至第一电子激发态A~1Πv′态,测量各个振动态的荧光光强随时间演化,测量结果表明DBr (v″=8、7)与D_2的碰撞弛豫中均发生了二量子弛豫;对于摩尔配比为0.4的DBr(v″=8)和Ar混合体系,只有连续单量子碰撞弛豫过程.
Highly vibrationally excited DBr(X~1Σ~+,v″=8、7) is prepared using degenerated stimulated hyper-Raman(DSHR) excitation. Then the collisional relaxation process of excited DBr with D_(2 )(Ar) is investigated. For the DBr(v″=8) and D_(2 )(Ar) systems, High-resolution transient laser induced fluorescence(LIF) is used to detect collisionally relaxed DBr. When the total pressure remains unchanged and the molar ratio of the collision gas is changed, The effective life under corresponding conditions is measured. Based on the Stern-Volmer equation in the mixed gas system, the collision relaxation rate coefficients of DBr(v″=8) molecules with Ar, D_2 are yielded, which are k_8(Ar)=(0.51±0.1)×10~(-12 )cm~3molecule~(-1)s~(-1 )and k_8(D_2)=(3.50±0.8)× 10~(-12)cm~3molecule~(-1)s~(-1 ), respectively. The average self-relaxation rate coefficient of the DBr(v″=8) molecule is k_8(DBr)=(1.20±0.4)×10~(-12)cm~(3 )molecule~(-1)s~(-1). For DBr(v″=8, 7) and D_2 mixed systems with a molar ratio of 0.5, the Ti laser is used to probe the DBr v″≤ 8、7 vibration states. The decay signal of laser induced time-resolved fluorescence from A~1Π(v′)→X~1Σ~+(v″) transition is monitored. This liner region is dominated by two quantum relaxation(Δv=2) collisional propensity rules. For the mixed system of DBr(v″=8) and Ar with molar ratio of 0.4, the measurement results show that only one continuous single quantum collision relaxation(Δv=1) occurs.
Highly vibrationally excited DBr(X~1Σ~+,v″=8、7) is prepared using degenerated stimulated hyper-Raman(DSHR) excitation. Then the collisional relaxation process of excited DBr with D_(2 )(Ar) is investigated. For the DBr(v″=8) and D_(2 )(Ar) systems, High-resolution transient laser induced fluorescence(LIF) is used to detect collisionally relaxed DBr. When the total pressure remains unchanged and the molar ratio of the collision gas is changed, The effective life under corresponding conditions is measured. Based on the Stern-Volmer equation in the mixed gas system, the collision relaxation rate coefficients of DBr(v″=8) molecules with Ar, D_2 are yielded, which are k_8(Ar)=(0.51±0.1)×10~(-12 )cm~3molecule~(-1)s~(-1 )and k_8(D_2)=(3.50±0.8)× 10~(-12)cm~3molecule~(-1)s~(-1 ), respectively. The average self-relaxation rate coefficient of the DBr(v″=8) molecule is k_8(DBr)=(1.20±0.4)×10~(-12)cm~(3 )molecule~(-1)s~(-1). For DBr(v″=8, 7) and D_2 mixed systems with a molar ratio of 0.5, the Ti laser is used to probe the DBr v″≤ 8、7 vibration states. The decay signal of laser induced time-resolved fluorescence from A~1Π(v′)→X~1Σ~+(v″) transition is monitored. This liner region is dominated by two quantum relaxation(Δv=2) collisional propensity rules. For the mixed system of DBr(v″=8) and Ar with molar ratio of 0.4, the measurement results show that only one continuous single quantum collision relaxation(Δv=1) occurs.
引文
[1] Jongma R T,Wodtke A M.Fast multiquantum vibrational relaxation of highly vibrationally excited O2[J].J.Chem.Phys.,1999,111:10957.
[2] Lawrence W G,Van Marter T A,Nowlin M L,et al.Inelastic collision dynamics of vibrationally excited I2 (X)[J].J.Chem.Phys.,1997,106:127.
[3] Hartland G V,Qin D,Dai H L.Observation of large vibration-to-vibration energy transfer collisions (ΔE? 3500cm-1) in quenching of highly excited NO2 by CO2 and N2O[J].J.Chem.Phys.,1994,101:8554.
[4] Wang S,Zhang B,Zhu D,et al.Energy-dependence of vibrational relaxation between highly vibrationally excited KH (X1Σ+,v″=14-23) and H2,and N2[J].Spectrochim.Acta A,2012,96:517.
[5] Yamasaki K,Fujii H,Watanabe S,et al.Efficient vibrational relaxation of O2 (X3Σ-g,v= 8) by collisions with CF4[J].Phys.Chem.Chem.Phys.,2006,8:1936.
[6] Liu J,Shen X,Shen Y,et al.Resonant energy transfer between highly vibrationally excited RbH(RbD) and H2(D2)[J].Chem.Phys.,2013,425:62.
[7] Fedorov D A,Derevianko A,Varganov S A.Accurate potential energy,dipole moment curves,and lifetimes of vibrational states of vibrational states of heteronuclear alkali dimers[J].J.Chem.Phys.,2014,140:184315.
[8] Wall M C,Stewart B A,Mullin A S.State-resolved collisional relaxation of highly vibrationally excited pyridine by CO2:Influence of a permanent dipole moment[J].J.Chem.Phys.,1998,108:6185.
[9] Havey D K,Du J,Liu Q,et al.Full state-resolved energy gain profiles of CO2 (J = 2-80) from collisions of highly vibrationally excited molecules.1.Relaxation of pyrazine (E=37900cm- 1)[J].J.Phys.Chem.A,2009,114:1569.
[10] Du J,Sassin N A,Havey D K,et al.Full state-resolved energy gain profiles of CO2 from collisions with highly vibrationally excited molecules.II.Energy-Dependent pyrazine (E=32700 and 37900 cm-1) relaxation[J].J.Phys.Chem.A,2013,117:12104 .
[11] Plane J M C,Whalley C L,Frances-Soriano L,et al.O2(a1Δg)+Mg,Feand Ca:Experimental kinetics and formulation of a weak collision,multiwell master equation with spin-hopping[J].J.Chem.Phys.,2012,137:014310.
[12] Birzniece I,Nikolayeva O,Tamanis M,et al.B(1)1Π state of KCs:High-resolution spectroscopy and description of low-lying energy levels[J].J.Chem.Phys.,2012,136:064304.
[13] Hsu H C,Dyakov Y,Ni C K.Energy transfer of highly vibrationally excited biphenyl[J].J.Chem.Phys.,2010,133:598.
[14] Ziemkiewicz M P,Pluetzer C,Nesbitt D J,et al.Overtone vibrational spectroscopy in H2-H2O complexes:A combined high level theoretical ab initio,dynamical and experimental study[J].J.Chem.Phys.,2012,137:084301.
[15] Miguel B,Zuniga J,Requena A,et al.Relaxation pathways of the OD stretch fundamental of HOD in liquid H2O[J].J.Chem.Phys.,2016,145:244502.
[16] Czuprynski K,Han W.Energy dependent radiative transfer equation and energy discretization[J].J.Comput.Appl.Math.,2017,323:147.
[17] Wu D L,Tan B,Wen Y F,et al.The spectroscopic and molecular constants of low-lying excited states of MgCl molecule by multi-reference configuration interaction method[J].J.At.Mol.Phys.(原子与分子物理学报),2018,35:186 (in Chinese)
[18] WANG S Y,FAN W X,GAO Y M,et al.Vibrational to rotational energy transfer in highly vibrationally excited LiCs-CO2 collisions[J].J.At.Mol.Phys.(原子与分子物理学报),2017,34:678 (in Chinese)
[19] Yamasaki K,Fujii H,Watanabe S,et al.Efficient vibrational relaxation of O2(X 3Σ,v = 8) by collisions with CF4[J].Phys.Chem.Chem.Phys.,2006,8:1936.
[20] Kabir M H,Antonov I O,Heaven M C.Probing rotational relaxation in HBr (v = 1) using double resonance spectroscopy[J].J.Chem.Phys.,2009,130:074305.
[21] Kabir M H,Antonov I O,Merritt J M,et al.Experimental and theoretical investigations of rotational energy transfer in HBr + He collisions[J].J.Phys.Chem.A,2010,114:11109.
[22] Alghazi A,Liu J,Dai K,et al.Quantum state-resolved energy redistribution of highly vibrationally excited CsH (D) by collisions with H2 (D2)[J].Chem.Phys.,2015,448:76.
[23] Yang X,Kim E H,Wodtke A M.Vibrational energy transfer of very highly vibrationally excited NO[J].J.Chem.Phys.,1992,96:5111.
[2] Lawrence W G,Van Marter T A,Nowlin M L,et al.Inelastic collision dynamics of vibrationally excited I2 (X)[J].J.Chem.Phys.,1997,106:127.
[3] Hartland G V,Qin D,Dai H L.Observation of large vibration-to-vibration energy transfer collisions (ΔE? 3500cm-1) in quenching of highly excited NO2 by CO2 and N2O[J].J.Chem.Phys.,1994,101:8554.
[4] Wang S,Zhang B,Zhu D,et al.Energy-dependence of vibrational relaxation between highly vibrationally excited KH (X1Σ+,v″=14-23) and H2,and N2[J].Spectrochim.Acta A,2012,96:517.
[5] Yamasaki K,Fujii H,Watanabe S,et al.Efficient vibrational relaxation of O2 (X3Σ-g,v= 8) by collisions with CF4[J].Phys.Chem.Chem.Phys.,2006,8:1936.
[6] Liu J,Shen X,Shen Y,et al.Resonant energy transfer between highly vibrationally excited RbH(RbD) and H2(D2)[J].Chem.Phys.,2013,425:62.
[7] Fedorov D A,Derevianko A,Varganov S A.Accurate potential energy,dipole moment curves,and lifetimes of vibrational states of vibrational states of heteronuclear alkali dimers[J].J.Chem.Phys.,2014,140:184315.
[8] Wall M C,Stewart B A,Mullin A S.State-resolved collisional relaxation of highly vibrationally excited pyridine by CO2:Influence of a permanent dipole moment[J].J.Chem.Phys.,1998,108:6185.
[9] Havey D K,Du J,Liu Q,et al.Full state-resolved energy gain profiles of CO2 (J = 2-80) from collisions of highly vibrationally excited molecules.1.Relaxation of pyrazine (E=37900cm- 1)[J].J.Phys.Chem.A,2009,114:1569.
[10] Du J,Sassin N A,Havey D K,et al.Full state-resolved energy gain profiles of CO2 from collisions with highly vibrationally excited molecules.II.Energy-Dependent pyrazine (E=32700 and 37900 cm-1) relaxation[J].J.Phys.Chem.A,2013,117:12104 .
[11] Plane J M C,Whalley C L,Frances-Soriano L,et al.O2(a1Δg)+Mg,Feand Ca:Experimental kinetics and formulation of a weak collision,multiwell master equation with spin-hopping[J].J.Chem.Phys.,2012,137:014310.
[12] Birzniece I,Nikolayeva O,Tamanis M,et al.B(1)1Π state of KCs:High-resolution spectroscopy and description of low-lying energy levels[J].J.Chem.Phys.,2012,136:064304.
[13] Hsu H C,Dyakov Y,Ni C K.Energy transfer of highly vibrationally excited biphenyl[J].J.Chem.Phys.,2010,133:598.
[14] Ziemkiewicz M P,Pluetzer C,Nesbitt D J,et al.Overtone vibrational spectroscopy in H2-H2O complexes:A combined high level theoretical ab initio,dynamical and experimental study[J].J.Chem.Phys.,2012,137:084301.
[15] Miguel B,Zuniga J,Requena A,et al.Relaxation pathways of the OD stretch fundamental of HOD in liquid H2O[J].J.Chem.Phys.,2016,145:244502.
[16] Czuprynski K,Han W.Energy dependent radiative transfer equation and energy discretization[J].J.Comput.Appl.Math.,2017,323:147.
[17] Wu D L,Tan B,Wen Y F,et al.The spectroscopic and molecular constants of low-lying excited states of MgCl molecule by multi-reference configuration interaction method[J].J.At.Mol.Phys.(原子与分子物理学报),2018,35:186 (in Chinese)
[18] WANG S Y,FAN W X,GAO Y M,et al.Vibrational to rotational energy transfer in highly vibrationally excited LiCs-CO2 collisions[J].J.At.Mol.Phys.(原子与分子物理学报),2017,34:678 (in Chinese)
[19] Yamasaki K,Fujii H,Watanabe S,et al.Efficient vibrational relaxation of O2(X 3Σ,v = 8) by collisions with CF4[J].Phys.Chem.Chem.Phys.,2006,8:1936.
[20] Kabir M H,Antonov I O,Heaven M C.Probing rotational relaxation in HBr (v = 1) using double resonance spectroscopy[J].J.Chem.Phys.,2009,130:074305.
[21] Kabir M H,Antonov I O,Merritt J M,et al.Experimental and theoretical investigations of rotational energy transfer in HBr + He collisions[J].J.Phys.Chem.A,2010,114:11109.
[22] Alghazi A,Liu J,Dai K,et al.Quantum state-resolved energy redistribution of highly vibrationally excited CsH (D) by collisions with H2 (D2)[J].Chem.Phys.,2015,448:76.
[23] Yang X,Kim E H,Wodtke A M.Vibrational energy transfer of very highly vibrationally excited NO[J].J.Chem.Phys.,1992,96:5111.