共查询到17条相似文献,搜索用时 78 毫秒
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酮类分子反应是大气化学反应中的一个中间反应.在300--500K范围内,我们对酮类分子和O(~3P)原子反应速率常数作了系列测定.为了估算大气化学和燃烧化学反应条件下的反应速率常数,本文用过渡态理论将实验结果外推到200—2000K范围内.同时对 相似文献
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碳氢化合物被NO_x光氧化过程中会产生中间物质酮类化合物,与烷烃、烯烃不同的是,这类化合物与大气化学中感兴趣的自由基,如O、OH等的基元反应研究得不多。除有少量关于O(~3p)与丙酮反应速率常数测定的报道外,前文还报道了O(~3p)与丁酮反应速率常数的测定,并得出该反应速率常数与温度关系的Arrhenius表达式。 相似文献
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本文报道了用流动放电-化学发光技术测定O(~3P)和硅烷化学反应速率常数.在293—413K范围内, 结果为k=(1.05±0.36)×10~(-10)exp[(-3.06±0.10) kcal·mol~(-1) /RT] cm~3·molecule~(-1)·s~(-1)并用过渡态理论将上述实验结果外推到200—2000 K范围内. 计算结果以三参数公式表示为: k=7.67×10~(-19) T~(2.59) exp(-720 cal·mol~(-1)/RT) cm~3·molecule~(-1)·s~(-1). 相似文献
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CH2O+O[3P]→CHO+OH反应途径和变分速率常数 总被引:1,自引:0,他引:1
采用QCISD/6-311G[d,p]从头算方法,优化了吸氢反应CH2O+O[3P]→CHO+OH的反应物、过渡态和产物的几何结构,并用QCISD(t,full)/6-311G**//QCISD/6-311G**方法对各驻点进行了单点校正,得出正逆反应的活化位垒分别为38.86kJ@mol-1和67.23kJ@mol-1.IRC(内禀反应坐标)分析指出,该反应是一个C-H键断裂和H-O键生成协同进行的反应,而且在反应途径上存在一个引导反应进行的振动模式,其引导反应进行s区间为-0.4~0.75(amu)1/2.在1300~2270K温度范围内运用改进的变分过渡态理论(ICVT),计算了反应速率常数,与实验结果相当一致. 相似文献
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CH2O+O[^3P]→CHO+OH反应途径和变分速率常数 总被引:1,自引:0,他引:1
采用QCISD/6-311G犤d,p犦从头算方法,优化了吸氢反应CH2O+O犤3P犦→CHO+OH的反应物、过渡态和产物的几何结构,并用QCISD(t,full)/6-311G//QCISD/6-311G方法对各驻点进行了单点校正,得出正逆反应的活化位垒分别为38.86kJ·mol-1和67.23kJ·mol-1.IRC(内禀反应坐标)分析指出,该反应是一个C-H键断裂和H-O键生成协同进行的反应,而且在反应途径上存在一个引导反应进行的振动模式,其引导反应进行s区间为-0.4~0.75(amu)1/2.在1300~2270K温度范围内运用改进的变分过渡态理论(ICVT),计算了反应速率常数,与实验结果相当一致. 相似文献
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The metastable molecule CS(a~3Π) has been obtained, by the energy transfer reaction of He(2~3S) with CS_2 in a discharge-flow system The technique of fixed observation-point was used to obtained the quenching rate constants of CS(a~3Π) with various reagents CO_2, CS_2, ICl, H_2O, NOCl, CH_2Cl_2, CHF_2Cl and SF_6. Thc mechanism for quenching has been discussed. 相似文献
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在束-气装置上的单次碰撞条件下, 利用低压直流放电选择性地激发碱土金属到亚稳态, 观察了Ca(~1S)、Ca(~1S’~3P)、Ba(~1S)、Ba(~1S, ~3D)+ClO_2。反应的化学发光. 通过测量化学发光总包光强的空间分布, 得到这些反应的总碰撞截面为: Ca(~1S)+ClO_2, 0.97 nm; Ca(~3P)+ClO_2, 1.38 nm; Ba(~1S)+ClO_2, 13.6 nm; Ba(~3D)+ClO_2, 2.39 nm, 计算机模拟化学发光光谱, 发现新生产物MO(M=Ca, Ba)的电子激发态A~1П态的相对振动布居分布是非玻尔兹曼分布的, 求出反应Ba(~3D)+ClO_2和Ca(~3P)+ClO_2产生的MClC~П→X~2 ∑~+跃迁的化学发光截面分别为0.51 nm和0.31 nm, 计算光谱中不同成份的光强, 得到了反应产生MO、MCl的产物分支比. 最后, 讨论了这类反应的机理。 相似文献
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The variation of ehemiluminescent polarization for reaction Ba(~1S)+N_2O with respect to the Ba beam temperature or the average collision energy E_(rtr) was studied under the single collision condition on beam-gas apparatus. If E_(rtr)<0.06 eV, the distribution of rotational angular momentum for product BaO, i.e. -, increased with the impact energy; while E_(rtr)>0.06 eV, - decreased with the E_(rtr). It is plausible to point out the corresponding relationship between the characteristics of the reaction potential surface and the conformation of the intermediate complexes. 相似文献
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The emission spectra of BiO has been first obtained by studying the reaction: Bi+O_2(~1△_g)in the atomic-beam apparatus. 22 new bands has been obtained from the emission spectra of BiO (A ~2Π_g) which are attributed to the collisional energy transfer process of BiO(X,v)+O_2(b ~1Σ_g~+). The O_2(b ~1Σ_g~+) is produced by the following process: O_2(~1△_g)+O_2(~1△_g)→O_2(b ~1Σ_g~+)+O_2(X ~3Σ_g~-). 相似文献
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This paper reported an observation of the chemiluminescence in the 400~900 nm spectral region produced by the crossed molecular beam reaction of F(~2P) with CH_2Br_2, as well as the reaction mechanism. Under single collision condition, only vibrationally excited HF~≠(X,V) (V≤3) can be observed. In the case of multicollision, in addition to V≤3, HF~≠(X,V) with V>3 and electronically excited Br_2~*(B), BrF~*(B) have been detected. The equilibrium rotational temperature for HF(3,0) band is 320 K, and the relative population ratio of different V levels of HF is N_3:N_4:N_5=0.69:1.00:0.12. 相似文献
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Ca(1S0)+CH2Cl2、CHCl3和Ca(3P)+CH2Cl2、CHCl3反应的动态学研究 总被引:1,自引:0,他引:1
The reactions Ca(~1S_0)+ CH_2Cl_2, CHCl_3 and Ca(~3P)+ CH_2Cl_2, CHCl_3 were studied by means of the laser induced fluorescence (LIF). Systematic simulation of the observed LIF spectra revealed that change of the Ca atoms from the ~3p states to the ~1S_0 state brought about a decrease of the fraction of total energy going to the ground state CaCl product vibration and an increase of the fraction of total energy going to the ground state CaCl product rotation. Total cross sections for the reactions of Ca(~1S_0)+CH_(4-n)Cl_n(n=2, 3) and the fraction of the Ca atoms going to the ~3P states in the discharge Ca beam were estimated from the LIF indensity of the CaCl product and total cross sections for the reactions Ca(~3P)+CH_(4-n)Cl_n. They are 0.39±2 nm, 0.45±2 nm, 1.8+0.1%, respectively. 相似文献
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I. B. C. Matheson 《Photochemistry and photobiology》1979,29(5):875-878
Abstract— The chemical reaction rate constant of bilirubin with singlet oxygen in basic aqueous solution has been redetermined to be 3.5 × 108 M-1 s-1 by a competitive technique using a 1,3-diphenylisobenzofuran in sodium dodecyl sulfate micelles. Bilirubin also physically quenches a singlet oxygen with a rate constant of 9 × 108 M -1 s-1 . The lifetime of singlet oxygen in D2 O solution has been determined to be 35 μ s . The absorption cross-section for the molecular oxygen 3 ∑g -→1 δ g + 1 v electronic transition at 1.06μn in aqueous solution is unexpectedly larger than the gas paase cross-section. 相似文献
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The vibrationally excited OH(v) from the reaction of O(~1D)+Si(CH_3)_3Cl was observed by UV laser photolysis/FTIR emission spectroscopy. The vibrational number was only up to 3 with a ratio of 1:0.8:0.1 for v=1:2:3. Comparing this result with the similar reaction of O(~1D)+Si(CH_3)_4 which OH(v) vibrational number was high up to 4 with a ratio of 1:1:1:0.3 for v=1:2:3:4 under the same experimental conditions, it was found that the substitution of Cl for CH_3 affected the extent of heavy Si atom blocking the energy migration in a molecule. This results identifies the prediction that the characteristic of electrons in central atom plays an important role in intramolecular energy transfer. 相似文献