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1.
(R)- and(S)-2-Allyl-1,3,2-dinaphtho (α,β) [d.f] dioxaborepin ((R)-2 and(S)-2) have been first prepared by the reaction of(R)-(+)- or(S)-(−)-1, 1′-bi-2-naphthol and triallylborane in THF at room temperature, respectively.(S)-2 and(R)-2 are sensitive to moisture and oxygen in air and disproportionate easily to triallylborane and 1,1′-bi-2 naphthyl bis (1,1′-bi-2-naphtholborate) at ambient temperature. However, THF is a stabilizer for them. The reactions of(R)-2 or(S)-2 and some aliphetic or aromatic aldehydes in CH2Cl2 at −78°C for several hours afforded β-alkylenyl alcohols in up to 84.8%ee. Among them, optically active 1-(3, 5-dichlorophenyl)-3-butenol and 1-(2-methoxyphenyl)-3-butenol were first prepared Foundation item: Supported by the National Natural Science Foundation of China (29972033) Biography: Liu Dejun (1973), male, Ph. D, research direction: asymmetric synthesis  相似文献   

2.
The studies on model systems XAuPH3(X-H,F,Cl,Br,I,CN,CH3)have been carried out by using ab intiol HF and DFT B3LYP methods at pseudopotential and double-zeta LANL2DZ level.The results are compared with those of MP2,The properties of the models.i.e.the atomic net charge populations.the frontier molecular orbitals and nonlinear optical(NLO)properties have been investigated under an applied electric field on the basis of optimized structures.The computational results show that for these models characterized as electron acceptor-metal-electron donor(A-M-D)system,the NLO properties are due to intramolecular charge-transfer interaction between the acceptor and the donor.The more charges transfer gives,the better NLO properties.In the selected model systems,IAuPH3 has the biggest βvec and γof 1184.1942 a.u.and 17341.9214 a.u.,whereas IC6H4PH3^ ,A TYPICAL a-π-D organic conjugated system,has βvec and γof 710.7697 and 11664.1405 a.u.respectively.In comparison.IAuPH3 has significant NLO properties.  相似文献   

3.
Ternary inclusion complexes β-cyclodextrin (β-CD), rare earth metal ions (YbCl3, YCl3), and 1,8-naphthalene- diamine/1,5-naphthalenediamine are synthesized in basic aqueous media, which are characterized via 1H NMR and IR spectroscopy. The stoichiometric proportion of β-CD:YbCl3:1,5-naphthalenediamine is 2:1:2, that of β-CD:YCl3:1,8-naphthalenediamine is 2:1:1, and that of β-CD:YbCl3:1,8-naphthalenediamine is 2:1:1. The IR spectroscopy of the ternary inclusion complexes in the range of 935–1 000 cm−1 reveals the existence of the coordinate bond M—O or M—N. The possible conformations of the ternary inclusion complexes are depicted. Biography: JIANG Huiming(1972–), male, Associate professor, research direction: molecular complex chemistry, supramolecular chemistry.  相似文献   

4.
5,11,17,23-Tetrakis-1′, 1′-dimethylethyl-25,27-dihydroxy-26,28-1″, 7″, 13″-trioxa-4″, 10″-dithiatridecylcene-calix[4]arene (calix[4]dithiacrown-5) and its O-methylated derivate (dimethylcalix[4]dithiacrown-5) were synthesized fromp-tert-butylcalix[4] arene via 1, 3-lower rim functionalization with chloroethyltosylate, followed by ring-closing condensation with β,β/t'-dimercaptoethyl ether in the presence of sodium ethoxide as a base in reflux ethanol under nitrogen atmosphere, followed by methylation with methyltosylate in the presence of NaH as a base in dioxane. It was found that they can coordinate with platinous chloride and the platinous complexes are efficient catalysts for the hydrosilylation of olefins with triethoxysilane. Foundation item: Supported by National Natural Science Foundation of China Biography: CHEN Yuan-yin (1936-), male, Professor.  相似文献   

5.
Using a new ground-state ab initio potential energy surface reported by Deskevich et al., the product polarizations in the reactions F+HCl→HF+Cl and F+DCl→DF+Cl were studied by employing the quasi-classical trajectory method. At a collision energy of 10 kcal/mol, the four generalized polarization-dependent differential cross-sections (2π/σ)(dσ00/dω t ), (2π/σ)(dσ20/dω t ), (2π/σ)(dσ22+/dω t ) and (2π/σ)(dσ21−/dω t ) were calculated in the center-of-mass frame. The distribution of the angle between k and j′, P r ), the distribution of the dihedral angle denoting the k-k′-j′ correlation, P r ), and the angular distribution of the product rotational vectors in the form of polar plots P r , φ r ) were also calculated. The evident influence of isotope substitution on the product polarization is revealed. This effect may result from the different mass factors of the two reactions.  相似文献   

6.
Fe+ ion beams with the energy of 110 keV were implanted into films of L(+)-cysteine (HSCH2CH(NH2)COOH). One of the single crystals grown in hydrochloric acid solution with the implanted samples through slow evaporation was structurally characterized by the X-ray crystallography. The crystal is monoclinic, space group C2, with a = 1.8534(4) nm, b = 0.5234(1) nm, c = 0.7212(1) nm, β= 103.72°, V = 0.67965(3) nm3, Z = 4, F(000) = 144.0, D{clac} = 1.763 g · cm−3, μ(MoK a = 1.06 mm−1, T = 293(2) K. R = 0.0379, wR = 0.0835 for 660 observed reflections (I > 2σ(I)). The structural formula of the crystal compound is (CH2CH(NH2)NO2)ClFe (M r = 180.38 u). Products of heavy ion beam irradiation were purified and it was directly confirmed that the implanted Fe+ ions had been deposited in the novel molecules. The same doses of Fe+ ion beams of the same energy were implanted into films of L(+)-cysteine hydrochloride monohydrate. FTIR spectroscopy of the implanted samples proved that some of the original molecules were seriously damaged and significant modifications were induced.  相似文献   

7.
A set of molecule parameters, namely, N, N′, p, q, n, were used to express the structures of alkanes. A correlative model was established between certain physical-chemical properties and molecular parameters of alkanes by regression method. Eight physical-chemical properties, such as evaporation heat (△vHm^20), density(D^20 ), capacity (C^20), surface tension (δ^20), boiling point (Tb), critical temperature(Tc), critical pressure(Pc) and critical volume(Vc), of fifty-six C3-C16 alkanes were calculated directly from the model in this paper. The calculated values are in good accordance with the literature ones reported for alkanes, and the correlation coefficients (R) equal or exceed 0.99 . The research results indicate that the principle of the method is simple and clear, the method is practical, the correlativity is excellent, and the predicted data are credible.  相似文献   

8.
Keggin-type phenylimido-polyoxometalates α-[PM12O39NPh]3− (M = W and Mo) have been systematically investigated on the electronic structures, redox as well as nonlinear optical (NLO) properties by density functional theory (DFT). The strong M≡N bond confirmed by natural bond orbital (NBO) analysis comprises one s bond and two π bonds, the same as Mo≡N in [Mo6O18NPh]2−. Furthermore, phenylimido segment effectively modifies the electronic properties of α-[PM12O39NPh]3−. On one hand, when enlarging the inorganic cluster from {Mo6O18} to {PMo12O39}, the energy gap between HOMO and LUMO in α-[PMo12O39NPh]3− decreased, resulting in enormously anodic shift for the reduction potential, while the excitation energy is less and the total second-order polarizability β 0 is up to 438-3×10−30 esu, which is nearly 10 times larger than that of [Mo6O18NPh]2−. On the other hand, when metal W in α-[PM12O39NPh]3− is substituted by Mo, the interaction between Mo and N is enhanced and the redox ability becomes stronger. The β 0 value for α-[PMo12O39NPh]3− is more than 5 times higher than that of α-[PW12O39NPh]3−. It indicates that changing appropriate metal or enlarging the inorganic cluster will improve the redox properties and second-order nonlinear response. Moreover, the electron transition for three compounds mentioned above occurred mainly from organoimido segment (as the electron donor) to polyanion cluster (as the acceptor). As a result, α-[PMo12O39NPh]3− may be a promising candidate for oxidant and nonlinear optical material. Electronic Supplementary Material  Supplementary material is available for this article at and is accessible for authorized users. Supported by National Natural Science Foundation of China (Grant No. 20573016), Training Fund of NENU’s Scientific Innovation Project (Grant No. NENUSTC07017), Science Foundation for Young Teachers of Northeast Normal University (Grant No. 20070304) and Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT)  相似文献   

9.
Resonance-enhanced multiphoton ionization (REMPI) spectra of N^32S and N^34S have been recorded in the range of 35700-40200 cm^-1. The radical was generated by a pulsed dc discharge of a mixture of SF6 and N2 under a supersonic free jet condition. All the 16 observed bands of N^32S radicals have been assigned, among which 12 bands belong to three transition progressions (v′=0-4, 0), (v′=1-4, 1) and (v′=2-4, 2) from the X^2П ground state to the B′^2∑^+ upper state and the rest correspond to (9, 0), (10, 0), (11, 0) and (12, 0) bands of B^2П-X^2П transition, respectively. Analysis of the rotationally resolved spectra yields exhaustive spectroscopic constants of both the X^2П ground state and the B′^2∑^+ excited state. The electronic transition bands of the isotopic molecule N^34S have been rotationally analyzed for the first time and the rotational constants of the ground and upper states have been determined simultaneously.  相似文献   

10.
The nonlinear refractive indexesn 2 for the ethanol solutions of 1, 10-phenanthroline (2.0 × 10−3 mol · L−1), [bis(l, 10-phenanthroline) lanthanum (III)] nitrate (1.0 × 10−3 mol · L−1), and [nitrato-fluoracil-bis (1, 10-phenanthroline) lanthanum (III) ] nitrate (1.0 × 10−3 mol · L−1) are first measured, the third-order nonlinear optical susceptibilities χ(3) and 〈γ〉 are calculated, and the mechanisms of the third-order optical nonlinearities enhanced by lanthanum (III) are discussed preliminarily.  相似文献   

11.
The bis(β-diketonato) Zr complexes CpZr(acac)2Cl (acac = acetylacetonato) (1) and Cp*Zr(acac)2Cl (2) can be synthesized by the reac-tion of Cp′ZrCl3(Cp′ = Cp or Cp*) with 2 equiv of lith-ium acetylacetonate. CpZr(acac)2Cl (1) can be quan-titatively prepared by treatment of Cp2ZrCl2 with ex-cess acetylacetone. The tris(β-diketonato) Zr com-plex CpZr(tfac)3 (tfac = trisfluoroacetylacetonato) (3) has been prepared by treatment of CpZrCl3 with so-dium trisfluoroacetylacetonate. The replacement of both chlorine atoms and one Cp group from zir-conocene dichloride by nonfluorinated diketone,acetylacetone,readily occurs at room temperature in triethylamine medium,offering the tris(β-diketonato) Zr complex CpZr(acac)3 (4). The complexes were characterized by 1H NMR spectroscopic methods. In addition,the molecular structures of complexes 3 and 4 have been determined by X-ray diffraction methods. When activated by excess methylaluminoxane (MAO),these complexes were active for ethylene polymerization,offering polyethylenes with high mo-lecular weights and narrow molecular weight distribu-tions. Complex 4 showed a very high ethylene po-lymerization activity of up to 7100 kg PE/mol Zr·h at 5 atm. Complexes 1 and 2 were also active for ethyl-ene/1-hexene copolymerization.  相似文献   

12.
Inclusion complex of Orange II with β-Cyclodextrin (β-CD) and the anti-photolysis effect under UV-light were investigated. The molar ratio of inclusion complex of β-Cyclodextrin and Orange II is 1∶1. The formation constantK = 1.236×103 L/mol was determined by the UV and Fluorescence spectra respectively, which was quite in accordance with the calculation with a modified Benesi-Hildbrand equation. The inclusion complex was characterized by the IR spectra and the molar ratio of inclusion complex is 1∶1 too. The formation constantK = 1.266×103 L/mol was determined by1H NMR analysis and was nearly the same by UV and fluorescence spectra. The photocatalytic decolorization rate of Orange II solutions containing β-CD and TiO2 was smaller by 51.9% than that of the Orange II solutions only containing TiO2, while in the case of direct photolysis of Orange II solutions, β-CD can lower the photolysis rate by 48.1% under UV-light. This result indicates β-CD can inhibit the photolysis and photocatalytic decolorization of Orange II under UV-light. The β-CD inclusion complex was found to be persistent to UV-light photolysis. Foundation item: Supported by the National Natural Science Foundation of China (20177017) Biography: Lu Ping (1958), male. Associate professor, research direction: environmental photochemistry.  相似文献   

13.
0 IntroductionTriamcinoloneAcetonide,9 fluoro 11β,2 1 dihydroxy 16α,17[(1 methylethylidene)bis (oxy) ] pregn 1,4 diene 3,2 0 dione,Mris 4 34.4 8(abr.TA ) .Itbelongstoaclassofadrenalcortexhormonedrug ,whosefunctionsareaffectionofsugarmetabolism ,anti inflammationandresistancehypersusceptibilityetc.TAcanbesuitabletorheumatoidarthritisanddermatosissuchashypersusceptibilityandneuropathicdermatitis .ThefunctionsofTAisstrongerandlongerthantriamcinolone[1 ,2 ] .ThecommonmethodsofdetectingTAm…  相似文献   

14.
The synthesis, characterization and luminescent properties of aluminum complexes containing a dianionic N-aryloxo functionalized β-ketoiminate ligand are presented. 4-(2-Hydroxy-5-R-phenyl)imino-2-pentanone (R = Me, L1H2; R = tert-butyl, L2H2) ligands reacted with AlEt3 in tetrahydrofuran to give the aluminum complexes (L1AlEt)2 (1) and (L2AlEt)2 (2) in reasonable isolated yields. X-ray diffraction revealed that complexes 1 and 2 have solvent-free centrosymmetric dimeric structures, and each aluminum center has distorted trigonal bipyramidal geometry. At room temperature, complexes 1 and 2 exhibit blue photoluminescence in acetonitrile with maximum emission wavelengths of 419 and 413 nm, respectively.  相似文献   

15.
The relaxation of the highly vibrationally excited CO (v = 1–8) by CO2 is studied by timeresolved Fourier transform infrared emission spectroscopy (TR FTIR). 193 nm laser photolysis of the mixture of CHBr3 with O2 generates the highly vibrationally excited CO(v) molecules. TR FTIR records the intense infrared emission of CO(v→v-1). The vibrational populations of each level of CO(v) have been determined by the method of spectral simulation. Based on the evolution of the time resolved populations and the differential method, 8 energy transfer rate constants of CO(v = 1–8) to CO2 molecules areobtained: (5.7±0.1), (5.9±0.1), (5.2±0.2), (3.4±0.2), (2.4±0.3), (2.2±0.4), (2.0±0.4) and (1.8±0.6) (1014 cm3 · molecule−1 · s−1), respectively. A two-channel energy transfer model can explain the feature of the quenching of CO(v) by CO2. For the lower vibrational states of CO, the vibrational energy transfers preferentially to the u3 mode of CO2 For the higher levels, the major quenching channel changes to the vibrational energy exchange between CO(v→v-1) and the u1 mode of CO2.  相似文献   

16.
Flavonols are plant pigments that are ubiquitous in nature. Morin and other related plant flavonols have come into recent prominence because of their usefulness as anticancer, anti-tumor, anti-AIDS, and other important therapeutic activities of significant potency and low systemic toxicity. The heat of combustion of morin (molecular formula, C15H10O7·H2O) in oxygen was measured by a rotating-bomb type combustion calorimeter, the standard molar enthalpy of combustion of morin at T = 298.15 K was determined to be Δc H m (C15H10O7·H2O, s) = −(5 937.99 ± 2.99) kJ · mol−1. The derived standard molar enthalpy of the formation of morin in solid powder state at T = 298.15 K, Δf H m (C15H10O7·H2O, s), was −(1 682.12 ± 3.58) kJ · mol−1, which provide an accurate data of the stability of morin to the pharmacy and pharmacology. Biography: HOU Hanna(1956–), female, Visiting researcher, Associate professor of Hubei University of Education, research direction: thermochemistry.  相似文献   

17.
Asian dust storms originating from the arid regions of central and eastern Asia and from the Loess Plateau in China frequently occur in spring [1,2]. Driven by the East Asian monsoon, Asian dust can be transported to northern Pacific Ocean[2―8]. Asian du…  相似文献   

18.
Scalar multiplication [n]P is the kernel and the most time-consuming operation in elliptic curve cryptosystems. In order to improve scalar multiplication, in this paper, we propose a tripling algorithm using Lopez and Dahab projective coordinates, in which there are 3 field multiplications and 3 field squarings less than that in the Jacobian projective tripling algorithm. Furthermore, we map P to(φε^-1(P), and compute [n](φε^-1(P) on elliptic curve Eε, which is faster than computing [n]P on E, where φε is an isomorphism. Finally we calculate (φε([n]φε^-1(P)) = [n]P. Combined with our efficient point tripling formula, this method leads scalar multiplication using double bases to achieve about 23% improvement, compared with Jacobian projective coordinates.  相似文献   

19.
Let (t)(tR + N ) be the d-dimensional N-parameter generalized Brownian sheet. We study the polar sets for (t). It is proved that for any aR d , P{ (t) = a, for some tR > N } = and the probability that (t) has k-multiple points is 1 or 0 according as whether 2kN > d(k − 1)β or 2kN < d(k−1)α. These results contain and extend the results of the Brownian sheet, where R > N = (0,+∞) N ,R + N =[10,+∞) N ,0< α≤1 and β≥1. Biography: LI Huiqiong (1966–), female, Associate professor, research direction: stochastic process and random fractal.  相似文献   

20.
Song  Jirong  Chen  Zhaoxu  Xiao  Heming  Hu  Rongzu  Li  Fuping 《科学通报(英文版)》1999,44(3):214-218
[Li(NTO)(H2O)2] was prepared by mixing the aqueous solution of 3-nitro-1,2,4-triazol-5-one (NTO) and lithium hydroxide. The crystal structure of [Li(NTO)(H2O)2] was determined by single crystal diffraction analysis. The crystal is monoclinic, space group P21/n with crystal parameters of a = 0.742 0(2) nm, b = 0.344 9(1) nm,c = 2.490 6(3) nm, β= 94.89(1)°, Z = 4,D c , = 1.799 g cm−3,V = 0.635 nm3, μ = 1.591 cm−1, F(000) = 392. The finalR is 0.051. The MNDO MO calculation shows that the coordinate bonds of title compound possess certain extent of covalent character. O2 atom of NTO anion is bonded to Li atom; the nitro group will be lost first when NTO is decomposed.  相似文献   

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