杯芳烃接枝超细SiO2的制备及其对Cu2+、Ag+萃取性能的研究

通过对杯[4]芳烃以及杯[6]芳烃上缘进行烯丙基化和硅氢加成2步衍生化反应得到硅氢化杯[4]芳烃以及硅氢化杯[6]芳烃,再将这2种硅氢化杯芳烃衍生物分别接枝到超细SiO₂上。在不同的pH值条件下,就2种杯芳烃接枝超细SiO₂衍生物对水合Cu²⁺及Ag⁺的萃取性能进行了研究。结果表明,与对叔丁基杯芳烃相比较,杯芳烃接枝超细SiO₂衍生物对Cu²⁺和Ag⁺的萃取率都有所提高,其中杯[4]芳烃接枝超细SiO₂对Ag⁺的最高萃取率达到98.78%,杯[6]芳烃接枝超细SiO₂对Cu²⁺的最高萃取率达到67.74%。     

脯氨酸与Cu、Cu+和Cu2+配位体系的计算研究

运用M06-2X和ωB97XD方法分别在6-311++G（2d,p）和TZVP基组水平上,对脯氨酸（Pro）的15种构象与Cu、Cu⁺和Cu²⁺形成的多种配合物的几何结构、能量学特征、振动光谱和电子结构等进行计算研究. 四种水平得到20种[Pro-Cu]、16种[Pro-Cu]⁺和16种[Pro-Cu]²⁺稳定结构. [Pro-Cu]和[Pro-Cu]⁺体系中出现12种Pro构象,而[Pro-Cu]²⁺体系中出现11种Pro构象,三种体系中最稳定的结构都不是由能量最低的Pro构象生成的. 在结构CI3、CI4、CII7和CII8中,Pro的羧基氢转移到亚氨基氮形成两性离子与Cu双配位结合. [Pro-Cu]^0/1+/2+体系四种水平计算相对能差范围逐渐增加,结合能分别在-60.0 --5.0 kJ·mol^-1、-340.0 --170.0 kJ·mol^-1和-1100.0 --860.0 kJ·mol^-1范围,配位体系中Pro的变形能逐渐增加. N―H和O―H键伸缩振动频率普遍发生红移,配位体系中部分电荷从Pro转移到Cu上,在[Pro-Cu]²⁺体系中单配位结构中电荷转移最多,约为单位负电荷.     

Asymmetrical nitrogen-40;1 Geminal systems-261 N-chlorohydrazines3

The factors determining the kinetic and thermodynamic stabilities of N-chlorohydrazines are discussed. Acyclic N-chlorohydrazines exist only as trialkyldiazenium chlorides 3a,b. Chlorination of 2-acyl-1, 1-dimethylhydrazines 6a,b gave 1,4-diacyl-2,3-dimethylhexahydro-1,2,4,5-tetrazines 7a,b via hydrazyl radical intermediates, and chlorination of a 1-phenylpyrazolidin-5-one 8 gave phenylazoisovaleric esters 9a,b. Stable N-chlorohydrazines were obtained from bicyclic hydrazines; viz. the 2-chloro-1,2-diazabicyclo [2.2.2]octan-3-one 12 and 7-chloro-1,7-diazabicyclo[2.2.1]heptane 16. The restricted inversion of N(7) in 16 and its 1-methyl quaternary salt 21 were observed in the ¹³C-NMR spectra. The acyclic N-chloro-hydrazinium salt 25 was isolated.     

Cation transport at 25°c from binary Na+Mn+, Cs+Mn+ and Sr2+Mn+ nitrate mixtures in a H2OCHCl3H2O liquid membrane system containing a series of macrocyclic carriers

Cation fluxes from binary mixtures of either Na⁺, Cs⁺ or Sr²⁺ with other alkali metal cations, alkaline earth metal cations, and Pb²⁺ through a H₂OCHCl³H₂O bulk liquid membrane system containing one of several macrocyclic carriers have been determined Nitrate salts were used in all cases. The most selective transport of Na⁺ over all other cations studied was found with the carrier cryptand [2.2.1]. Selective transport of Na⁺ relative to Li⁺, Cs⁺ and the alkaline earth cations was found with cryptand [2.2.2B] and cryptand [2.2.2D]. The ligands 21-crown-7 and dibenzo-24-crown-8 showed selective transport of Cs⁺ over the second cation in all cases. Several macrocycles showed selectivity for Sr²⁺ over the second cation with the macrocycle 1,10-diaza-18-crown-6 showing the highest selectivity for this cation of all ligands studied. Relative fluxes from binary cation mixtures are rationalized in terms of macrocycle cavity size, donor atom type and ring substituents.     

The electronic structure of N4O62+ and the bonding interaction of NO+ and NO3−

The results are reported of an MO-SCF-CNDO/2 study of the experimental and optimal geometries of the N₄O₆²⁺ion cluster. The calculations are shown to support the stable existence of the N₄O₆²⁺ complex and the suggestion of its discoverers [1] on the role of NO⁺ in the N₂O₄ solutions. The proposed interpretation of the bonding interaction explains why the shortest N β O distances are found with the NO⁺ ions which have their nitrogen atoms displaced out of the NO₃^? plane.     

The predictable behaviour of cations deriving from endo-4-chlorotetracyclo[3.3.0.0.2,8O.3,6]octane.

Silver cation-initiated ionization of the title compound in aqueous dioxane gives the exo and endo-tetracyclo[3.3.0.0.^2,8O.^4,6]octane-3-ols (35 and 65%). Thermal isomerization in chloroform gives the exo and endo isomers of 4-chlorobicyclo[3.2.1]octa-2,6-dienes (3.5 and 1.5%) and 6-chlorotricyclo[3.2.1.0.^2,7]oct-3-ene (90 and 5%). The behaviour of the cations involved is compatible with MINDO/3 calculations.     

Coordination de la phosphine organo-fer [CpFeIIC6Me5CH2PPh2]+ au RhI et proprietes spectroscopiques,electrochimiques et catalytiques des complexes heterobinucleaires FeII-RhI

The reactions between the phosphine-organoiron [CpFe^II-η⁶-C₆Me₅CH₂PPh₂]⁺ PF₆^? (1) and [RhCl(η⁴-diolefin)(μ-Cl)]₂ in CH₂Cl₂ at reflux give the new heterobinuclear air-stable crystalline complexes [CpFe^II-η⁶-C₆Me₅CH₂)P(Ph)₂Rh(η⁴-diene)Cl]PF₆,(D'*-diene=cyclooctadiene (COD): 65%, 2; trimethylfluorobenzobicyclo[2.2.2]octadiene (Me₃TFB): 48%, 3). Complexes 2 and 3 have been studied by ¹H, ¹³C and ³¹P NMR spectroscopy and they are carbonylated (CO, 1 atm). Cyclic voltammetry experiments with addition of MeOH show electron transfer Fe^IRh^I → Fe^IIRh⁰, the presence of a catalytic wave Fe^I/Fe^II and the possible formation of Rh hydrides. Under normal conditions 2 is a catalyst for hydrogenation of cyclohexene, but it is less efficient than the known mononuclear Rh¹ analogues.     

THE MORPHOLOGY AND STRUCTURE OF POLYETHYLENE TEREPHTHALATE SPHERULITES

The morphology and structure of three types of normal and abnormal spherulites of polyethylene terephthalate cast from solution in dimethylphthalate were studied by polarizing microscopy, transmission electron microscopy and electron diffraction techniques. In the normal negative spherulites the [0]~* direction is parallel to the radius direction. In the normal positive spherulites the radius direction is parallel to the [6]~*. In the abnormal PET spherulites the Maltese cross extinction pattern in the polarizing microscope under crossed polars is oriented at 45°to the polars and there are concentric extinction rings around the center of the spherulite. Electron diffraction pattern indicates that [2]~* is parallel to the radius of the spherulite and this explains the observed extinction pattern, in the abnormal spherulite.     

协同萃取液膜体系从Li+、Na+、K+混合溶液中提取Li+

从卤水、海水中提取Li是目前较为活跃的研究课题。用液膜法从Li~+、Na~+、K~+混合溶液中分离Li~+的报道很少。协同效应在乳状液型液膜中的应用还未见报道。本文采用噻吩甲酰三氟丙酮(HTTA)和磷酸三丁酯(TBP)作为混合载体的液膜体系,快速、高效地从Li~+、Na~+、K~+的混合溶液中分离、浓缩Li~+,为从卤水、海水中提取Li~+提供了重要的依据。     

Zur kenntnis von [O2]22+[Ti7F30]2−

[O₂]²⁺₂[Ti₇F₃₀]^2? has been obtained by reaction of TiO₂ with a mixture of fluorine and oxygen (p_F2/O2 ≈ 300–3500 atm., t ≈ 300–450°C) either as colourless powder or in form of colourless, clear needles. From single crystal studies the spacegroup is P$\text{3}$ - C_3i¹ (No. 147) with a = 10.19₂, c = 6.50_o Å, Z = 1. The crystal structure has been refined to R = 0.086 [R_w = 0.058] (748 unique reflexions [F_o > 2σ(F_o)]). From the structure determination [O₂]²⁺₂[Ti₇F₃₀]^2? has isolated columns of partially distorted [TiF₆] octahedra (- column structure) which are connected only quite loosely by (disordered) O₂⁺ cations. ν_O2+ is at 1857 cm^?1, the magnetic moment μ_eff = 2.35 B.M. (295 K) is quite as expected for a ‘spin-only’ case.     

Solvated positron chemistry. II. The reaction of hydrated positrons with Cl−, Br− and I− ions

The reaction of the hydrated positron, e_aq⁺ with Cl^?, Br^?, and I^? ions in aqueous solutions was studied by means of positron The measured angular correlation curves for [Cl^?, e⁺], [Br^?, e⁺, and [I^?, e⁺] bound states were in good agreement with th Because of this agreement and the fact that the calculated positron wavefunctions penetrate far outside the X^? ions in the [X^?, e⁺] sta propose that a bubble is formed around the [X^?, e⁺] state, similar to the Ps bubble found in nearly all liquids. F^?ions did not react w Preliminary results showed that CN^? ions react with e_aq⁺ while OH^?ions are non reactive. The rate constants were 3.9 × 10¹⁰ M^?1 s^?1, 4.4 × 10¹⁰ M^?1 s^?1, and 6.3 × 10¹⁰ M^?1 s^?1 for Cl^?, Br^?, and I^?, respectively, at low (? 0.03 M) X^? concentrations. A 25% decrease in the rate constant caused by the addition of 1 M ethanol to the I^? solutions was i The influence of halide ions on the positronium (Ps) yields in pure water was studied by use of lifetime measurements. The Cl^?, Br^?, and I^? ions reduced the Ps yields at low concentrations (? 0.03 M), while F^? ions only reduced the Ps-yield However, the Ps yields saturated (e.g. at ≈ 21% ortho-Ps yield in the Cl^? case) at higher concentrations. This saturation and the high-concentration effects-in the angular correlation results were interpreted as caused by rather complicated spur effects, wh It is proposed that spur electrons may pick off the positron from the [X^?, e⁺ states with an efficiency which depends on the structure of the     

Complexation of [2.2]paracyclophane with an (η5-cyclopentadienyl)iron+ moity: mono- and di-cations

The reaction of [2.2]paracyclophane with ferrocene in the presence of AlCl₃ and Al/powder gives the new compounds [1-6-η-[2.2]paracyclophane- (η⁵-cyclopentadienyl)iron]⁺[PF₆] and [1-6-η; 9-14-η-[2.2]paracyclophane- [(η⁵-cyclopentadienyl)iron]₂]²⁺[PF₆]₂ in high yields. The species have been characterized by elemental analysis, and by ¹H and ¹³C NMR spectroscopy.     

Stability constants of complexes of Li+, H3O+, NH 4+ and Ag+ with hexaethyl calix[6]arene hexaacetate in nitrobenzene saturated with water

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M⁺(aq)+NaL⁺(nb)⇔ML⁺(nb)+Na⁺(aq) taking place in the two-phase water-nitrobenzene system (M⁺ = Li⁺, H₃O⁺, NH₄⁺, Ag⁺; L = hexaethyl calix[6]arene hexaacetate; aq = aqueous phase, nb = nitrobenzene phase) were determined. Furthermore, the stability constants of the ML⁺ complexes in water saturated nitrobenzene were calculated; they were found to increase in the cation order H₃O⁺<NH₄⁺<Li⁺<Ag⁺.     

Stability constants of the Li+, Na+, H3O+, NH4+, Ag+, and K+ complexes of the cone conformer of tetraethyl p-tert-butyltetrathiacalix[4]arene tetraacetate in nitrobenzene saturated with water

Abstract  

From extraction experiments in the two-phase water–nitrobenzene system and γ-activity measurements, the stability constants of the tetraethyl p-tert-butyltetrathiacalix[4]arene tetraacetate (cone)·M⁺ complexes (M⁺ = Li⁺, H₃O⁺, NH₄ ⁺, Ag⁺, or K⁺) were determined in water-saturated nitrobenzene. It was found that these constants increase in the cation order NH₄ ⁺ < K⁺ < H₃O⁺ < Ag⁺ < Li⁺ < Na⁺.     

KINETICS OF SUSPENDED EMULSION POLYMERIZATION OF METHYL METHACRYLATE*

 The kinetics of suspended emulsion polymerization of methyl methacrylate (MMA), in which water acted as the dispersed phase and the mixture of MMA and cyclohexane as the continuous phase, was investigated. It showed that the initial polymerization rate (R_p0) and steady-state polymerization rate (R_p) were proportional to the mass ratio between water and oil phase, and increased as the polymerization temperature, the potassium persulphate concentration ([I]) and the Tween20 emulsifier concentration ([S]) increased. The relationships between the polymerization rate and [I] and [S] were obtained as follows: R_p0∝[I]^0.71[S]^0.23.The above exponents were close to those obtained from normal MMA emulsion polymerization. It also showed that the average molecular weight of the resulting poly(methylmethacrylate) decreased as the polymerization temperature,[I]and [S] increased. Thus, MMA suspended emulsion polymerization could be considered as a combination of many miniature emulsion polymerizations proceeding in water drops and obeyed the classical kinetics of MMA emulsion polymerization.     

Structure des ions [C4H7O]+ obtenus par fragmentations du [1-methylcyclobutanol]

The mass spectra of metastable molecular and fragment ions demonstrate that the loss of CH₃^. from [1-methylcyclobutanol]^.+ leads competitively to three different ions: $\text{a}$ = protonated cyclobutanone; $\text{b}$ = [n-C₃H₇CO]⁺ and $\text{c}$ = protonated methylvinylketone.     

The synthesis of 2,6-dimethylenetricyclo[3.3.0.03,7]octane

The synthesis of the title compound is reported together with that of 2-methyl-6-methylenetricyclo[3.3.0.0^3,7]octane. During the synthesis a rearrangement of the tricyclo[3.3.0.0^3,7]octane skeleton to the tricyclo[3.2.1.0^3,6]octane system has been observed.     

Regularities of the trans-Influence of Ligand L on the Energy Characteristics of the Metastable Isomers of trans-[RuX4(NO)L]q (L = H2O, NH3, Pyrazine, Cl?, OH?, CN?, NO2?; X = Cl?, NH3)

The geometric structures of the ground state and metastable isomers of the nitroso complexes trans-[RuCl₄(NO)L]^q (L = H₂O, NH₃, pyrazine (Pz), q = −1; Cl⁻, OH⁻, CN⁻, NO ₂ ⁻ , q = −2) and cis[RuCl₄(NO)L]^q (L = Pz, q = −1) were optimized in terms of the density functional theory. The variation of the trans-ligand L influences the relative energy of the metastable isomer with a side NO coordination. The presence of π-acceptor substituents in the trans-ligand L decreases the energy.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 8, 2005, pp. 606–611.Original Russian Text Copyright © 2005 by Lyubimova, Sizova.     

Darstellung und eigenschaften von 124,2,4,6-thiatriazin-1-oxiden. zur struktur der hydrolyseprodukte von 1-arensulfonyl-imino-1λ4,2,4,6-thiatriazinen

Synthesis and structure of 4-phenoxy-H[1λ⁴,2,4,6]thiatriazino[4,3a]benzimidazole-2-oxide 5, 3-amino-4H[1λ⁴,2,4,6]thiatriazino[2,3-a]benzimidazole-1-oxide 6 and 3-amino-5-dimethylamino-2-tosyl-1λ⁴, 2,4,6-thiatriazine-1-oxide 7, obtained by hydrolysis of the corresponding arenesulfonyl imino compounds are discussed. The molecular and crystal structure of N-benzoyl-? tosyl-guanidine is presented.     

Theoretical Study on Inverse Sandwich Complexes [E-C{5-n}H{5-n}Nn-E]+ and [E-C{5-n}H{5-n}Pn-E]+ (n=1, 2, 3; E=Al,Ga, In,Tl)

The inverse sandwiches [E-C_{5-n}H_{5-n}N_n-E]⁺ and [E-C_{5-n}H_{5-n}P_n-E]⁺ (n=1, 2, 3; E=Al, Ga, In, Tl) with low-valent boron group elements are studied. The (η5,η5) coordinated inverse sandwich [E-C_{5-n}H_{5-n}N_n-E]⁺ is unstable in energy or nonexistent. However, the (η5,η5) coordinated [E-C_{5-n}H_{5-n}P_n-E]⁺ is not only stable in energy, but also stable against dissociation. The dissoction stability [E-C_{5-n}H_{5-n}P_n-E]⁺ with the same E element decreases as the number n increases, while for the certain n number, the dissociation energies with different E elements are close to each other. [E-C₄H₄P-E]⁺ has similar dissocition stability to the well-known [E-C₅H₅-E]⁺. The inteaction between C_{5-n}H_{5-n}P_n and lowvalent E element is mainly ionic. Since lone pairs of electrons locate on both E and P atoms, the (η5, η5) coordinated inverse sandwich [E-C_{5-n}H_{5-n}P_n-E]⁺ would act as multi electron-donors.