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Azapropellanes have been extensively studied for their special application. Debenzylation of pentabenzylpentaaza[3,3,3]propellane was studied in this paper. The N-benzyl groups were removed by catalytic hydrogen transfer under the mild conditions with simple process. The yield of the debenzylation product was lower. Their structures of all compounds were confirmed by spectra.

Five sesquiterpenoids were isolated from 90% ethanol extract of Croton yunnanensis by silica gel,Sephadex LH-20 column chromatography,as well as prep-HPLC methods. Based on MS,1 D and 2 D NMR spectral analyses,the structures of the five compounds were identified as 11-methoxyl alismol(1),6β,7β-epoxy-4α-hydroxyguaian-10-ene(orientalol C,2),multisalactone D(3),arvestonol(4),and 4,5-dihydroblumenol A(5). Compound 1 was a new guaiane-type sesquiterpenoid. Compounds 2-4 were isolated from the Croton genus for the first time,and compound 5 was obtained from this plant for the first time.

The heterogeneous photo-Fenton process is still inhabited by the poor recycling of Fe(III)/Fe(II). Therefore, a visible light active α-FeOOH/BiOI catalyst was prepared by facile precipitation method. The synthesized photocatalysts were characterized by different methods, such as XRD, SEM, HR-TEM, XPS. Results showed that the loose flocculent of α-FeOOH covered on the BiOI particle. Rhodamine B was selected to evaluate the photocatalytic performance under visible-light irradiation in the presence of H2O2. The superior photocatalytic activity of 0.5M-FeOOH/BiOI was obtained that 100% of RhB can be degraded within 20 min illumination. UV–vis diffuse reflectance spectra and the photoluminescence measurements revealed that the 0.5M-FeOOH/BiOI composite enhanced charge carrier separation in the way of Fe(III) consumed photo electron to form Fe(II). Simultaneously, the acceleration of Fe(III)/Fe(II) recycling is beneficial to catalyze H2O2 to form hydroxide radical (·OH). Photo stability further revealed that the 0.5M-FeOOH/BiOI composite could be a promising material in wastewater treatment and other environmental remediation applications.

An electrochemical multicomponent [3 + 1 + 1] annulation used for the synthesis of 1,3,5-trisubstituted 1,2,4-triazoles has been developed under transition-metal-, acid-, base- and external-oxidant-free conditions. In an undivided cell, a variety of hydrazones and aldehydes smoothly participate in this transformation to furnish a range of substituted 1,2,4-triazoles. The reaction constitutes a new transformation from hydrazones, aldehydes and NH4OAc into 1,2,4-triazoles, providing a unifying, simple and environmentally friendly approach to the currently available methods.

Four new triterpene glycosides, named salaciacochinosides A-D (1–4) were isolated from the 90% ethanol extract of Salacia cochinchinensis, together with five known compounds 2α,3β,23-trihydroxyurs-12,18-dien-28-oic acid 28-O-β- d -glucopyranoside (5), racemiside (6), alangiplatanoside (7), acantrifoside E (8), and syringin (9). The structures of the four new triterpenoids were characterized by chemical methods and MS, IR, 1D and 2D NMR spectral analyses. The α-glucosidase inhibitory activities of the nine compounds were assessed, compounds 6 and 7 showed remarkable α-glucosidase inhibitory activities, with IC50 values of 0.44 and 0.75 μM, respectively. Compounds 1–5 exhibited moderate α-glucosidase inhibitory activities, and compounds 8 and 9 showed none α-glucosidase inhibitory activity in our current experiments.

In this paper, two 3D anionic metal–organic frameworks, [(CH3CH2)2NH2]·[Zn(BTC)1/3(PyC)]·1/2CH3CN·2H2O (NKU-102) and [(CH3CH2)2NH2]·[Zn2(BTC) (PyC)]·1.5H2O·DEF (NKU-103), were constructed from the same reaction system at different temperature. Though both are of anionic framework, NKU-102 possesses a sealed 3D framework based on octahedral cage and shows negligible adsorption capacity of organic dyes, whereas NKU-103 features an open triangular microchannel surrounded by two types of helical chains, and thus exhibits outstanding size-selective adsorption toward small cationic organic dyes.

Cz n-type Si (100) wafers are implanted with 190 keV O and 40 keV H ions in different implantation sequences. Cross sectional transmission electron microscopy and slow positron annihilation spectroscopy are used to study the formation and evolution of micro-defects. Our results clearly show that the defect morphology depends strongly on the implantation sequence. Large cavities are observed in O preimplanted samples, while only platelets are observed in H preimplanted samples. The change regularity of the S parameter is the same for the Si samples co-implanted at different sequences. But in H preimplanted samples, the S parameter is a little higher. The effects of the implantation sequence on the micro-defects have been discussed in combination with H and O implantation-induced defects as well as their interactions upon annealing.

Predicting the evolution of concentration distribution for contaminant transport in wetland flows has a wide range of ecological applications. To account for the ecological effect such as substrate absorption, the influence of bed absorption on the dispersion process of contaminant transport in a wetland channel with rectangular cross-section is analytically investigated in this study by the technique of long-time asymptotic expansion. The combined effects of bed absorption, free-water-surface-effect and the bank-sidewall-effect are demonstrated, by parameter analysis in terms of the bed absorption coefficient and the aspect ratio of the channel section. The studied cases illustrate that bed absorption decreases the total mass of the contaminant cloud retained in the flow and causes the contaminant cloud to concentrate more in the upper layer. The mean advection velocity of the contaminant cloud increases as the intensity of bed absorption amplifies. Environmental dispersivity is augmented with bed absorption in a deep wetland channel, which is inverse in a shallow channel. The effect of bed absorption weakens the positive skewness of the cross-sectional mean concentration distribution when the wetland channel approaches square, while strengthens the negative skewness of the cross-sectional mean concentration distribution when the channel is relatively shallow. Moreover, the cross-sectional mean concentration decays faster under the effect of bed absorption. For applications, the critical length and duration of the influenced region are presented with bed absorption.

Two novel terpenoids, named norperovskatone (1), biperovskatone (2) were isolated from the cultured Perovskia atriplicifolia, together with five known compounds. Compound 1 was a novel C18 nor-diterpenoid featuring a unique seco-ring C. Compound 2 was an unusual dimer including two different diterpenoid units. The structures of the two novel compounds were established by comprehensive spectroscopic analysis, as well as by crystal X-ray diffractions. All of the isolates were evaluated for their anti-HBV activities. Compounds 1 and 2 were found to possess remarkable anti-HBV activity.

In order to describe the morphology of diamond films, we have developed a geometrical growth model which takes into account the displacement of the observed faces [1].We will see how to establish the topologies that are potentially accessible to CVD diamond growth.Lastly, we will present results showing the influence of the occurrence of certain crystalline faces on the film characteristics. From these results, we will show how the growth model and to establish a growth strategy aimed at obtaining large usable surface area crystals.

The growth of CVD diamond film was simulated by using revised KMC method. The simulation was conducted at CH3 radical concentration (0.01%-0.03%) and atomic hydrogen concentration (0.01%-0.5%). The results showed that: The CVD diamond film growth under revised KMC method is superior, which is in good agreement with the experimental results. The concentration of CH3 ([CH3]) and the concentration of atomic H ([H]) can produce important effects on the film deposition rate, surface roughness and the concentration of atom H embedded in the film.

In order to understanding of the fate and transport of TiO2 nanoparticles (NPs) in the water treatment process, this study focused on the particle surface characteristics and hydrodynamic properties at different humic acid (HA) concentration, using aluminum sulfate (AS) as a coagulant. The changes of zeta potential of humic acid capped TiO2 NPs and flocs were measured by Malvern Zetasizer nanoZS. The surface functional group of flocs was investigated using FT-IR spectra. The growth velocity of alum-TiO2 NPs flocs were determined using a small-angle light scattering technique during the coagulation process.Experimental results indicated that the zeta potential of alum-TiO2 NPs flocs surface after adsorption of humic acid was related with humic acid concentration. Adsorption of humic acid resulted in more negative electrophoresis on the surface. Size and growth velocity of alum-TiO2 NPs flocs were estimated at different humic acid concentration. It was found that the flocs growed were faster in the presence of humic acid, while humic acid had adverse influences on the growth of alum-TiO2 NPs flocs.

It is studied that influence of Li vapor transport equilibration (VTE) on surface refractive index of congruent Mg (4.5 mol%):LiNbO3crystal at wavelength of 1536 nm. The results show the ordinary index nodecreases when t < 40 h, then recoveries slightly and tends to a constant when t >100 h. The extraordinary index nehas the VTE effects as similar as no, but the alteration amplitude is smaller than no. The secondary ion mass spectrometry) study shows that the VTE induces Mg diffusion within the crystal in an inhomogeneous Mg depth profile, depending on the VTE duration. The neutron activation analysis shows that the VTE hardly induces Mg evaporation away from the crystal. First, the Mg ions of crystal internal diffused to the surface in the early stage of VTE, and then they diffused slowly back into the bulk of the crystal toward equilibrium when Li concentration tends to equilibrium.

In order to understanding of the fate and transport of TiO2 nanoparticles (Nps) in the water treatment process, this study focused on the impact of humic acid (HA) on the aggregation and charge behavior of TiO2 Nps, and investigated the removability of TiO2 Nps stabilized by HA during the coagulation process. Malvern Zetasizer nanoZS measured the changes of size and zeta potential of HA capped TiO2 Nps (HA-TiO2). Uv-vis spectrometer examined the aggregation behavior of TiO2 and HA-TiO2 NPs at different pH value. Jar tests were conducted to evaluate the removal efficiency of TiO2 NPs. HA adsorbed on the surface of TiO2 Nps could decrease the zeta potential values and enhance the stability of TiO2 Nps. TiO2 Nps could be effectively removed by aluminum sulfate (AS) under favorable condition. HA could influence the removal of TiO2 Nps during the coagulation processes. Low concentration of HA rejected the removal efficiency of TiO2 Nps, however, high concentration of HA promoted removing effectiveness.

Metal–organic frameworks (MOFs) are typically built by assembly of metal centres and organic linkers, and have emerged as promising crystalline materials in a variety of fields. However, the stability of MOFs is a key limitation for their practical applications. Herein, we report a novel Sr 2+ -MOF [Sr 4 (Tdada) 2 (H 2 O) 3 (DMF) 2 ] (denoted as NKU- 105 , NKU = Nankai University; H 4 Tdada = 5,5'-((thiophene-2,5-dicar bonyl)bis(azanediyl))diisophthalic acid; DMF = N,N -dimethylformamide) featuring an open square channel of about 6 Å along the c -axis. Notably, NKU- 105 exhibits much outstanding chemical stability against common organic solvents, boiling water, acids and bases, relative to most MOF materials. Furthermore, NKU- 105 is an environment-friendly luminescent material with a bright cyan emission. This article is part of the themed issue ‘Coordination polymers and metal–organic frameworks: materials by design’.

The growth of {111}-oriented CVD diamond film under a two-step model was simulated at atomic scale by using revised KMC method. The simulation was conducted at various substrate temperature (1100K-1400K), CH3 radical concentration (0.01%-0.03%) and atomic hydrogen concentration (0.005%-0.3%). The results showed that: Substrate temperature (Ts), the concentration of CH3 ([CH3]) and the concentration of atomic H ([H]) can produce important effects on the film deposition rate and surface roughness.

A convenient and general method for acylation of free (N H) indoles via palladium-catalyzed decarboxylative cross-coupling reaction was developed. This process provided a useful method for the preparation of diverse 3-acylindoles in high yields utilizing a reaction with readily accessible reactants under mild conditions.

Congruent Er:Mg:LiNbO3 crystals were grown by the Czochralski method from the melts containing fixed 0.5 mol% Er2O3 while varied MgO content ranged from 0.0 to 8.0 mol%. The Mg and Er contents in the crystals were determined by neutron activation analysis. In the presence of Er codopant, the Mg threshold concentration with respect to optical damage is determined from the measured OH absorption spectra. The results show that the Er codopant has less effect on both the Mg threshold concentration and Mg segregation coefficient, which is within 1.13–1.23 as the Mg concentration is below the threshold while within 0.88–0.98 when above the threshold, consistent with the only MgO doping case. On the other hand, the practical Er concentration in the crystal is closely related to the Mg content and shows definite Mg threshold effect. Below the threshold, the Er concentration decreases linearly with the increased Mg concentration in the crystal; above the threshold, the decrease is more remarkable and follows another linear function. The Mg concentration effect on the Er segregation coefficient is discussed from the viewpoint of the Mg doping effect on the solubility of Er ions in the crystal.

The microtopography of manganese dioxide formed in situ was captured by AFM. The adsorptive properties of manganese dioxide formed in situ were evaluated for trace organic pollutants' removal with four different organic pollutants as the model organics which have different functional groups on aromatic ring. Several factors, such as the structure of manganese dioxide formed in situ , the adsorption time, the adsorbent concentration, and the background constituents (Ca 2+ , Mg 2+ , fulvic acid, etc.) in natural water, were investigated to evaluate their effects on adsorption. Results showed that manganese dioxide formed in situ had smaller particle size and higher adsorption capacity than the coagulated one. Ca 2+ and Mg 2+ added to the aqueous solution decreased the organics' removal significantly by accelerating the coagulation of manganese dioxide formed in situ and competing the adsorption sites with organics. The presence of fulvic acid had little impact on organic removal though it competes for the surface sites of manganese dioxide with organics. The four organics adsorbed on manganese dioxide formed in situ are listed in the order of decreasing reactivity: aniline > phenol > nitrobenzene > benzoic acid. The relative reactivity of organics was discussed in terms of electrostatic interaction between organics and adsorbent.

A new diferric complex, Fe2Lb, in which a DNA intercalator (acridine) is linked to a precursor diferric complex (Fe2La), has been designed and synthesised as a hydrolytic cleaving agent of DNA. Compared with Fe2La (without the DNA intercalator) (La: 2,6-bis{[(2-hydroxybenzyl)(pyridin-2-yl)methylamino]methyl}-4-methylphenol), Fe2Lb [Lb: 5-(acridin-9-yl)-N-(3,5-bis{[(2-hydroxybenzyl)(pyridin-2-yl)methylamino]methyl}-4-hydroxybenzyl)pentanamide] leads to a 14-fold increase in the cleavage efficiency of plasmid DNA due to the binding interaction between DNA and the acridine moiety. The interaction has been demonstrated by UV/Vis absorption, CD spectroscopy, viscidity experiments and thermal denaturation studies. The hydrolytic mechanism is supported by evidence from T4 DNA ligase assay, reactive oxygen species (ROS) quenching and BNPP [bis(4-nitrophenyl) phosphate, a DNA model] cleavage experiments. The pH dependence of the BNPP cleavage by Fe2La in aqueous buffer media shows a bell-shaped pH–kobs profile with an optimum point around a pH of 7.0 which is in good agreement with the maximum point of the pH-dependent relative concentration curve of active species from the pH titration experiments. The determination of the initial rates at a pH of 7.36 as a function of substrate concentration reveals saturation kinetics with Michaelis–Menten-like behaviour and Fe2La shows a rate acceleration increase of 4.7 × 106 times in the hydrolysis of BNPP. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Isolation and structural elucidation of norperovskatone (I) and biperovskatone (II) are described.

Three new compounds, atriplicone A (I), B (II), and C (III) are isolated together with five known compounds.

As DNA cleavage agent, a new diiron(III) complex (Fe 2 L b ), in which a DNA-intercalator (pyrene) is covalently linked to a diferric moiety, has been synthesized and characterized. The DNA-binding property and DNA cleavage activity of the complex have also been investigated.

The title compound, C5H9NO2, is almost planar (r.m.s. deviation for the non-H atoms = 0.036 Å) and an intramolecular N—H...O hydrogen bond generates an S(6) ring. In the crystal, N—H...O interactions link the molecules into C(6) chains propagating along [010].

Phenol was selected as a model compound. Factors, such as Ca2+, tannic acid, dose of kaolinite, dose of manganese dioxide formed in situ and pH, were invested on phenol removal in the process of enhanced coagulation by manganese dioxide formed in situ. Results showed that the addition of Ca2+ is beneficial for phenol removal. In the range of Ca2+ varied from 0 to 1.0 mmol x L(-1), the efficiency of phenol removal was enhanced more than 10%. Tannic acid can enhance phenol removal significantly when they are coexisted in water. As tannic acid was added to 10 mg x L(-1), phenol removal can be increased about 30% and 50% in the process of coagulation by AlCl3 and enhanced coagulation by manganese dioxide formed in situ, respectively. The dose of coagulant can be reduced in the process of enhanced coagulation with the addition of manganese dioxide formed in situ. The point of 1 mg x L(-1) manganese dioxide formed in situ linked with 30 mg x L(-1) AlCl3 can have the same phenol removal efficiency as the addition of 50 mg x L(-1) AlCl3. In the range of pH varied from 5 to 9, phenol can be removed with the high efficiency in the process of enhanced coagulation by manganese dioxide formed in situ. While under the strong acid condition and strong basic condition, phenol has lower removal efficiency.

An investigation is given to the bromate formation of catalytic ozonation in treating drinking water. It is shown that the c x t value of ozone depletion stage plays a more important role in BrO3(-) formation. Catalyst addition not only reduces the residual ozone content by 60.0% - 77.4% but also extends the ozone ID stage time from 4.3 min to 6.8 min, which makes the ozone c x t value shorter. A full-scale study indicates a very effective strength and performance of catalytic ozonation in controlling BrO3(-) formation and it is able to suppress BrO3(-) formation potential by 51.7% on average.

pH is the key factor to affect reaction process. Adsorption and redox take place at pHor =4 and pH4, respectively. Free-radical and Mn3+ was inferred to produce and participate in reaction at pH4. The oxidizing products of phenol are p-benzoquinone and biphenol determined by GC-MS. The efficiency of phenol and soluble manganese as a function of time and temperature were examined at pH4 in order to test the mechanism inferred. Results show removal percents of phenol increase from 65% to 95% with time varied from 10 min to 70 min, but soluble manganese changes little. Removal percents of phenol increase with temperature also, but soluble manganese doesn't change. This means fresh manganese dioxide is not the only oxidant in aqueous and other oxidant , i.e. Mn34+, appears during the reaction. High valence cation, i.e. Al3+, promoted the removal percent of phenol while anion, i.e. PO4(3-), decrease the efficiency of phehol.