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1.
Paul J. Dyson Petra Escarpa Gaede Brian F. G. Johnson John E. McGrady Simon Parsons 《Journal of Cluster Science》1997,8(4):533-545
On reaction with Ru3(CO)12, isopropenylbenzene and 4-phenyl-l-butene undergo hydrogenation, to yield the clusters, Ru6C(CO)14(6-C6H5CHMe2) 1 and Ru6C(CO)14(6-C6H5C4H9) 2, respectively. With allylbenzene, both hydrogenation and isomerization occurs affording Ru6C(CO)14(6-C6H5C3H7) 3 and Ru6C(CO)14(6-C6H5C3H5) 4. The structures of 1 and 2 have been established by single crystal X-ray diffraction. One of the Ru–Ru bond lengths in 2 is unusually long and extended Hückel molecular orbital calculations have been used in an attempt to rationalize this feature. 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
3.
《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
4.
运用MP2/aug-cc-pVDZ方法对2,5-二氢呋喃, 2,5-二氢噻吩与XF (X=F, Cl, Br)之间的卤键作用进行了理论研究. 研究发现: C4H6O, C4H6S与XF之间不仅存在O(S)…XF n型卤键, C=C双键与XF分子亦可形成π型卤键|对于C4H6O与XF之间的n型和π型卤键以及C4H6S与XF之间的π型卤键, 卤键键能ΔE、键鞍点处的电子密度ρ(rc)以及电子给体到受体之间的电子转移数Δq(XF)均按B…F2<B…ClF<B…BrF (B=C4H6O, C4H6S)的顺序依次增大|对于卤键键能较大的体系C4H6O…BrF(n), C4H6O…BrF(π), C4H6S…F2(n), C4H6S…ClF(n), C4H6S…BrF(n), C4H6S…BrF(π), 卤键作用介于离子键和共价键之间|而对于其它的卤键键能较小的体系, 卤键作用为闭壳层静电作用. 相似文献
5.
WANG Wen-Guo CHEN Chang-Neng LIU Qiu-Tian② 《结构化学》2005,24(7):821-824
1 INTRODUCTION Pronounced interest has recently been focused on the supramolecular chemistry and crystal enginee- ring of coordination compounds organized by coor- dinate covalent or molecular contacts like hydro- gen-bonding, π-π interactions, et al. because of their fascinating structure diversity and potential applica- tions as functional materials in catalysis and separa- tion[1]. A lot of infinite one-, two- and three-dimen- sional coordination frameworks have been synthe- sized, s… 相似文献
6.
《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 | — | — | — |