共查询到20条相似文献,搜索用时 15 毫秒
1.
《Chemical physics letters》1985,122(4):361-364
Reaction rate constants of SiH2(X̄1A1) have been directly measured for the first time using the laser photolysis—laser-induced fluorescence method. The preparation of SiH2 radical in the laser photolysis (193 nm) of phenylsilane and the concentration of the radical is demonstrated by a dye laser at 580.1 nm (X̄1A1-Ā1B1). The reaction rate constants of SiH2(X̄1A1) with H2, CH4, C2H4, SiH4 and Si2H6, are 0.001, 0.01, 0.97, 1.1 and 5.7×10−10 cm3 molecule−1 s−1, respectively. For SiH2(Ā1B1(0.2,0)), the collision-free lifetime is 0.6 μs and the quenching rate constant for He is 3.8×10−10 cm3 molecule−1 s−1. 相似文献
2.
采用自洽场分子轨道UHF/6-31G**从头算法,研究了1,2-C4H6→2-C4H6异构化反应机理,优化了基态势能面上反应物、过渡态、中间体和产物的几何构型,并对各驻点能量进行了零点能校准.结果表明该反应经历一个1-甲基环丙烯生成产物比经两步氢迁移反应历程更易发生. 相似文献
3.
4.
1 INTRODUCTION Metal organophosphonates have attracted considerable attention for over three decades due to their potential or practical applications, include- ing ion exchanges[1, 2], molecular sensors[3] and optics[4, 5]. Recently, a number of porous m… 相似文献
5.
采用自洽场分子轨道UHF/6-31G**从头算法,研究了1,2-C4H6→2-C4H6异构化反应机理,优化了基态势能面上反应物,过渡态,中间体和产物的几何构型,并对各驻点能量进行了零点能校准。结果表明该反应经历了一个1-甲基环丙烯生产产物比较两步氢迁移反应历程更易发生。 相似文献
6.
O. Amri S. Abid M. Rzaigui 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):766-777
The crystal structure of a new organic cation cyclohexaphosphate, [4-ClC 6 H 4 CH 2 NH 3 ] 4 Li 2 P 6 O 18 .4H 2 O, is reported. It crystallizes in the triclinic system (space group P-1) with the following unit-cell parameters: a = 9.628(8), b = 12.801(9), c = 19.528(6) Å, α = 78.60(4)°, β = 83.00(5)°, β = 89.98(4)°, Z = 2, and V = 2341(3)Å 3 . The structure has been solved using direct methods and refined by least-squares analysis [R 1 = 0.043, wR 2 = 0.108]. The structure can be described as infinite anionic layers with composition of [Li 2 (P 6 O 18 )(H 2 O) 4 ] 4 ? and parallel to the ac plane. The organic groups are located in the accessible voids. The molecules are stabilized by O─H…O and N─H…O types of intermolecular hydrogen bonds in the unit cell in addition to Van der Waals forces. 相似文献
7.
《Fluid Phase Equilibria》1999,165(2):157-168
A simple method is developed to estimate mixture critical temperatures (Tc), pressures (Pc), and densities (ρc) as a function of overall composition (X) from near critical region experimental coexistence data. This three-step method is applied to four mixtures, CO2–C3H8, CO2–nC4H10, C2H6–C3H8, and C3H8–nC4H10. Isothermal liquid–vapor coexistence data, which includes temperature, vapor pressure, coexisting densities (ρℓ and ρv), and coexisting compositions for the more volatile component (x1v and x1ℓ) are used. In the first step, the difference of the saturated liquid and vapor densities (ρℓ−ρv) is fitted to an empirical function in ((Pc−P)/Pc) to obtain Pc. Then P/Pc and ((ρℓ+ρv)/2ρc) are simultaneously fitted to functions of a polynomial in (X1−(x1v+x1ℓ)/2) yielding estimates of ρc and X1. Finally, the discrete estimated critical data points are fitted with an equation to provide a continuous representation of the critical lines. The method is successfully tested for the mixtures, CO2–C3H8 and CO2–nC4H10, for which there is a reasonable amount of isothermal data. The procedure is then applied to the mixtures, C2H6–C3H8 and C3H8–nC4H10, for which there are sparse data. For all four mixtures, the critical temperature line, Tc vs. X1, matches literature values within ±0.5%. The critical pressure line, Pc vs. X1, and critical density line, ρc vs. X1, match literature values, in general, within ±2%. 相似文献
8.
Egorova I. V. Zhidkov V. V. Grinishak I. P. Rodionova N. А. Bagryanskaya I. Yu. Pervukhina N. V. 《Russian Journal of General Chemistry》2021,91(7):1361-1367
Russian Journal of General Chemistry - It was first found that the alkylation of tris(4-N,N-dimethylaminophenyl)stibine with methyliodide leads to the formation of... 相似文献
9.
《Radiation Physics and Chemistry》1999,53(1):37-46
The mechanism and kinetics of energy transfer from Xe(6s[3/2]1) resonance state (E=8.44 eV) to selected hydrocarbon molecules have been investigated by XeCl(B–X) (λmax=308 nm) fluorescence intensity measurements at stationary conditions in Xe–CCl4–M systems. Steady-state analysis of the fluorescence intensity dependence on the xenon and M pressure at constant CCl4 concentration shows that these process occur in the two- and three-body reactions: Xe(6s[3/2]10)+M→products, Xe(6s[3/2]10+M+Xe→products. The two- and three-body rate constants for these reactions have been found (see Table 1Table 1. Experimental parameters of Eq. (8)found by least square method in Xe–CCl4–C2H2 and Xe–CCl4–C2H4 systems for chosen xenon pressures in the range 25–150 Torr. Linear correlation coefficients (R) are also shown
P(Xe) (Torr) | C2H4 | C2H2 | ||||
---|---|---|---|---|---|---|
Empty Cell | a | b×1016 cm3/molec. | R | a | b×1016 cm3/molec. | R |
25 | 0.92 | 3.26 | 0.98 | 1.00 | 2.78 | 0.95 |
40 | 0.86 | 3.29 | 0.97 | 1.00 | 2.91 | 0.98 |
50 | 0.87 | 3.33 | 0.97 | 0.99 | 3.05 | 0.98 |
60 | 0.85 | 3.33 | 0.97 | 1.02 | 2.99 | 0.98 |
75 | 0.86 | 3.39 | 0.97 | 1.03 | 2.95 | 0.98 |
90 | 0.92 | 3.30 | 0.97 | 1.03 | 2.85 | 0.98 |
100 | 0.92 | 3.21 | 0.98 | 1.0 | 2.77 | 0.98 |
110 | 0.88 | 3.19 | 0.96 | 1.02 | 2.71 | 0.99 |
125 | 0.86 | 3.12 | 0.95 | — | — | — |
140 | 0.92 | 2.90 | 0.95 | — | — | — |
150 | 0.95 | 2.77 | 0.94 | — | — | — |