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941.
报道了一种新型混价铜配合物[CuⅠCuⅡ(Ophen)2Cl]·H2O(HOphen=2-羟基-1,10′-邻菲咯啉)的水热合成和晶体结构.该化合物属于三斜晶系,P1空间群,a=0.91667(18)nm,b=1.0546(2)nm,c=1.1705(2)nm,α=80.50(3)°,β=80.56(3)°,γ=66.87(3)°,V=1.0202(3)nm3,Z=2,Dc=1.872Mg/m3,R1=0.0508,(wR2)=0.1481.标题化合物由一种新型的双核铜配合物和一个结晶水组成.邻菲咯啉在水热反应中发生羟基化,形成新型的羟基化邻菲咯啉.两个这样的配合物通过Cu…Cu间的范德华力相互作用形成二聚体.二聚体之间通过Ophen基团的π-π堆积以及C—H…Cl弱相互作用构筑成三维超分子网络.水分子处于网络的孔穴中.该化合物为邻菲咯啉的羟基化提供又一个新的范例. 相似文献
942.
采用量子化学的QCISD(T)/6-311 G(d,p)//BHandHLYP/6-311G(d,p)方法研究了氟代甲烷CH4-nFn(n=1~3)与CH3自由基氢抽提反应的微观动力学性质.并利用Polyrate程序分别计算了3个反应在200~3000K范围内的速率常数.计算结果表明,R1a,R2a和R3三个反应路径的反应能量分别为-12.7,-9.5和11.8kJ/mol,相应的能垒依次为67.0,62.2和67.5kJ/mol.在437K时,kCVT/SCT分别为6.72×10-19,8.01×10-18和8.82×10-20cm3/(molecule.s).计算结果还表明,在低温段反应的量子隧道效应显著,在计算温度范围内变分效应对反应速率常数的影响可以忽略. 相似文献
943.
944.
The synthesis, dual fluorescence, and fluoroionophoric behavior of two donor-sigma spacer-acceptor (D-s-A) compounds, trans-4-(N,N-bis(2-pyridyl)amino)methylstilbene (1H) and trans-4-(N,N-bis(2-pyridyl)amino)methyl-4'-cyanostilbene (1CN), are reported and compared to that of trans-4-(N,N-bis(2-pyridyl)amino)methyl-4'-(N,N-dimethylamino)stilbene (1DPA). To gain insights into the dual fluorescence properties for 1H and 1CN in polar but not in nonpolar solvents, model compounds resulting from a replacement of the stilbene group by alkyl (2R) or xylyl (2X) groups or from a replacement of the dipyridylamino (dpa) group by dianisoleamino (3AA), diethylamino (3EE), methylanilino (3MP), or diphenylamino (3PP) groups also have been investigated. In addition to 1H and 1CN, all four compounds of 3 display dual fluorescence. The locally excited (LE) fluorescence mainly results from the stilbene group and the ICT fluorescence from the through-bond interactions between the amino donor and the stilbene acceptors. In the presence of transition metal ions such as Zn(II), Ni(II), Cu(II), and Cd(II), the ICT processes are switched from dpa (D) --> stilbene (A) in 1H and 1CN to stilbene (D) --> dpa/metal ion (A) in their complexes. Whereas the ICT states for the complexes are generally nonfluorescent, an exception was found for the case of 1H/Zn(II). As a result, substituent-dependent fluoroionophoric behavior has been demonstrated by 1H, 1CN, and 1DPA in response to Zn(II). 相似文献
945.
IntroductionDAisoneofessentialparticipantsintheneuro transmissionprocessinmammaliancentralnervoussys tem .AlossofDA containingneuronsmayresultinsomeseriousdiseasesuchasParkinsonism .1Sinceitsdiscov eryinthe 195 0s ,DAhasbeenofinteresttoneuroscien tistsandchem… 相似文献
946.
Three new pavine N-oxide alkaloids, (-)-isocaryachine-N-oxide B, (+)-caryachine-N-oxide, (-)-caryachine-N-oxide, and a new isoquinoline alkaloid, 6,7-methylenedioxy-N-methylisoquinoline together with 11 known alkaloids were isolated and characterized from the stem bark of Cryptocarya chinensis. The structures of the isolated compounds were determined by spectral methods. The stereochemistry of pavine-N-oxide alkaloids is also discussed. 相似文献
947.
Jian Yan Xiang‐Ming Zhang Zhong‐Rong Li Lin Zhou Jian‐Chao Chen Li‐Rong Sun Ming‐Hua Qiu 《Helvetica chimica acta》2005,88(2):240-244
Three new triterpenoids, (3β,8β,14α,21α)‐26,27‐dinoronocerane‐3,8,14,21‐tetrol ( 1 ), (3β,8β,14α,21β)‐26,27‐dinoronocerane‐3,8,14,21‐tetrol ( 2 ), and lycopodiin A ( 3 ), together with four known compounds, lycoclavanol ( 4 ), lycoclaninol ( 5 ), α‐onocerin ( 6 ), and 3‐epilycoclavanol ( 7 ), were isolated from Lycopodium japonicum Thunb (Lycopodiaceae). Their structures were established by means of spectroscopic analyses. Compounds 3 and 7 showed moderate antitumor activity. Compounds 4 and 6 exhibited acetylcholinesterase inhibition activity. 相似文献
948.
Decomposition of Toluene and Acetone in Packed Dielectric Barrier Discharge Reactors 总被引:2,自引:0,他引:2
Chung-Liang?ChangEmail author Tser-Sheng?Lin 《Plasma Chemistry and Plasma Processing》2005,25(3):227-243
The influences of TiO2 catalytic material and glass pellet packing on the decomposition efficiency of toluene and acetone in air by dielectric barrier discharge (DBD) reactors were experimentally investigated in this study. The effects of both packing materials on the formation of byproducts such as CO and CO2 were also evaluated. Experimental results indicate that the introduction of glass materials into the plasma zone of a wire-tube reactor would improve the decomposition efficiency of toluene and acetone compared to a nonpacked reactor. The apparent decomposition rate constant of a glass packed-bed reactor was 4.5–4.8 times greater than that of a nonpacked reactor. The results also indicate that the decomposition rate constant of toluene was approximately 2.6 times higher than that of acetone no matter which type reactor was utilized. The application of TiO2 coated pellets in DBD reactors will enforce the hydrocarbon byproducts to further be oxidized to CO2, notwithstanding, it will not significantly improve the performance of the reactors in the decomposition of toluene and acetone, and in the formation of CO. The results show that the best selectivity of CO2 for acetone decomposition in a TiO2 coated pellets packed-bed reactor was approximately 40% higher than that in a glass packed-bed reactor. 相似文献
949.
C.S. Lin 《Chemical physics》1974,3(1):125-130
Accurate vibrational wave functions and a state-dependent model interaction potential were used in the study, within the framework of a semi-classical theory, of the vibrational excitation and dissociation of the hydrogen molecule in collinear collisions with the helium atom. A molecule initially in the excited state is shown to be very efficient in energy transfer and twice more likely to be further excited than to be de-excited. The change in the population distribution among the vibrational states at the first few collisions was analyzed. It is shown that the population of the first vibrational excited state ψ1 reaches its maximum after the very first collision and that of ψ2 after the second. It is also found that at a sufficiently high collision energy, ψ5 is the most efficient state in dissociation at the second collision while ψ6 contributes most at the third collision. 相似文献
950.
Two multidentate ligands: N,N′-di-(propionic acid-2′-yl-)-2,9-di-aminomethylphenanthroline (L1) and N,N′-di-(3′-methylbutyric acid-2′-yl-)-2,9-di-amino-methylphenanthroline (L2) were synthesized and fully characterized by 1H NMR and elemental analysis. The binding ability of L1 and L2 to metal ions such as M(II) (M = Cu, Zn, Co and Ni) and Ln(III) (Ln = La, Nd, Sm, Eu, and Gd) has been investigated by potentiometric
titration in aqueous solution and 0.1 mol dm−3KNO3 at 25.0 ± °C. In view of the structure of L1 and L2, mononuclear metal complexes can be formed in solution. The stability constants of binary complexes of ligands L1 and L2
with metal ions M(II) and Ln(III) have been determined respectively and further discussed. 相似文献