Laser-Induced Luminescence upon IR Multiphoton Excitation of Triethylsilane

A comparative study of the effect of IR laser radiation frequency on the yield of secondary reactions and luminescence intensity as functions of the laser pulse energy upon IR multiphoton dissociation of triethylsilane was performed. It was found that the reaction and luminescence threshold energies symbatically increase on passing from a frequency of 985 to 944 cm^–1. Based on experiments with xenon admixture to triethylsilane, it was concluded that the diethylsilyl radical, the product of the primary reaction of C–Si bond dissociation, plays the major role in the reactions of formation of luminescent species.     

Laser-Induced Luminescence upon IR Multiphoton Excitation of Diethylsilane

The general features of collisionless laser-induced luminescence upon the IR multiphoton dissociation of diethylsilane molecules were studied. The luminescence was detected in the wavelength region 400–700 nm, which is characteristic of the luminescence spectra of silylenes. Based on a comparative analysis of the luminescence behavior and product buildup kinetics in the IR multiphoton dissociation of diethylsilane, a conclusion was drawn that ethylsilyl radicals as the products of the primary reaction of C–Si bond dissociation play the main role in the formation of luminescent species.     

HCl分子在激光场中的多光子激发

用二次量子化方法讨论了ＨＣｌ分子在激光场中的多光子激发，还包括对ＨＣｌ分子伸缩振动能级的计算，跃迁概率随外场频率的变化及随时间的变化（取光场强度１０~（－８）Ｗ／ｃｍ~２）。     

The Reduction of Nitrobenzenes by Triethylsilane Using Wilkinson's Catalyst

Aromatic nitro compounds are effectively reduced to anilines by triethylsilane using Wilkinson's catalyst.     

Zinc-Catalyzed Reduction of Imines by Triethylsilane

Low-cost zinc is employed as a catalyst along with triethylsilane (TES) in a simple, straightforward, chemoselective reduction of various aldimines and ketimines to the corresponding secondary amines at room temperature and pressure.     

Infrared Multiphoton Dissociation of Diethylsilane Molecules under Collisionless Conditions

The IR multiphoton dissociation of diethylsilane under collisionless conditions was studied. It was found that the main unimolecular reactions are the dissociation of C–Si and C–C bonds. It was demonstrated that an increase in the number of substituent ethyl groups in going from diethylsilane to triethylsilane has no effect on the mechanism of primary reactions of the molecules but leads to the elevation of energy thresholds for primary and secondary reactions.     

臭氧分子在激光场中的多光子激发

采用二次量子化方法和酉变换讨论了O3分子在激光场中的多光子激发.推导出了O3分子的振动Hamiltonian 算子、从基态到各激发态的跃迁几率公式,以及O3分子从激光场中吸收的光子数公式,并分析了计算结果.这包括对O3分子伸缩振动能谱的计算及与实验结果的比较,跃迁几率随外场频率的变化、随时间的变化,以及O3分子在辐射场中的能量吸收情况(取光场强度为5×10-2 W/cm2).建立讨论所有具有C2v对称分子从基态到第四激发态以下各态多光子激发问题的模型.     

Angular Distribution of the Multipole and Multiphoton Photofragmentation of Molecules

The effect of higher-order photo-excitation on the angular distribution of photo-dissociated molecular fragments is studied. A general formalism is derived that will cover non-linear as well as linear polyatomic molecules and will permit comparison of the processes of different orders. Some of the higher-order processes, e.g., magnetic dipole and electric quadrupole, will give rise to azimuthal-angle (Φ) besides polar-angle (θ) dependence of the fragments. Using a molecule of D_3h, Symmetry as an example, a comprehensive study is made of all possible excitations allowed by symmetry in this point group for one-photon electric/magnetic dipole and three-photon electric-dipole transitions. Plane wave approximation is used for the relative motion of the random and non-rotating molecules which dissociate instantaneously with a velocity large compared with thermal motion. These basic angular factors may be used in future extensions to rotating and vibrating molecules and to time-delayed dissociations and to vibronically excited fragment states, etc.     

呋喃分子多光子电离解离过程的反应通道

The multiphoton ionization and fragmentation pathway of furan at 450nm is analyzed on the basis of statistical theory and Ladder-Switching model. Our calculation indicates that fragmentation takes plase after furan molecules absorb six photons of 450nm, C+ begins to appear after absorption of nine photons, production of C2+ ions needs absorption of at least 15 photons. Our interesting result is that C+ ions is produced by dissociation of C3H+, CH2+ and C3+ ions, not of C2+ ions. Theoretically computed relative abundance of C+/C2+ after absorption 15photons agrees well with our experimental results.     

呋喃分子多光子电离解离过程的反应通道

1引言呋喃分子在450nm附近的多光子电离实验中[1]，质谱中观察不到母体离子C4H4O＋，主要碎片离子的相对丰度C＋＞C2＋＝CHO＋＝C3H3＋．这些离子的选质量光谱研究表明它们是呋喃分子先吸收3＋1个光子电离为母体离子C4H4O＋，然后C4H4O＋再进一步吸收光子逐步解离产生．陕哺离子的初级解离过程已比较清楚[2－4]，吹响离子能量在1～5eV之间解离通道是：这三个平行解离反应可用RRKM理论来描述[4]．但是陕哺离子在高能量下的解离反应，特别是次级解离过程还不清楚，因此无法确定MPIF实验中观察到小离子碎片产生的机理，为此本文在速…     

分子转动和激光脉冲对多光子激发控制的影响(英文)

用解析代数方法研究了分子转动和激光脉冲对双原子分子多光子激发控制的影响并推导得到不同转动通道下的分子振动激发几率的解析表达式.为了考察转动能级和考虑分子转动后与激光场夹角的变化对分子多光子振动激发和振动激发控制的影响,我们计算并比较了分子纯振动和加入分子转动两种情况,并分别给出了分子与极化激光场在不同取向角下三光子选择激发的图像.研究发现分子的转动能级对多光子非共振激发有修正作用,但是分子转动会降低多光子激发的选择性,而选择合适的激光脉冲形状有利于目标多光子激发控制的实现.文中还进一步讨论了激光脉冲初相位对分子多光子激发控制的影响,发现脉冲初相位对多光子激发过程有明显的调制作用.     

乙胺和二甲胺分子(n_N,3s)里德堡态共振的多光子电离

MPI质谱研究作为化学分析和研究光物理过程的工具受到广泛的重视[1－4]．REMPI的特征过程是，首先分子吸收。个光子共振激发到中间态，然后处于中间激发态的分子再吸收n个光子激发到电离连续区[5]．REMPI的谱特征可以给出中间态分布的详细信息[6]，利用REMPI过程可研究单光子跃     

乙胺和二甲胺分子(n N,3s)里德堡态共振的多光子电离

The multiphoton ionization spectra of ethylamine and dimethylamine are presented in the 400-470nm region, with resonance excitation to 3s Rydberg state. The MPI fragmentation patterns of two C2H7N isomers are readily distinguished. For ethylamine, the most prevalent fragmentation is β-Cleavage, while for dimethylamine that is H atom ejection.     

The Effect of Vibrational Excitation of Molecules on Plasmachemical Reactions Involving Methane and Nitrogen

An experimental study of plasmachemical reaction involving CH₄ and N₂ molecules in rf discharge was studied in order to know the effect of vibrational excitation of N₂ molecules. When the relative nitrogen concentration was greater than 0.8, the main product of CH₄ decomposition was HCN, and the rate of methane decomposition at this condition was faster than that one in pure methane. These results could be confirmed through the mass spectroscopic method. The reason for these results is the vibrational energy of N₂ excited by rf discharge. The chain reaction mechanisms of producing HCN by vibrational excitation of N₂ were examined closely through numerical simulation. The rate-controlling step was the dissociation reaction of excited nitrogen molecule to the atomic nitrogen, so the process of HCN synthesis was limited by the value of reaction constant, k^N.