Issn: CN 22-1128/O6
Director:Chinese Academy of Sciences
Host:Changchun Institute of Applied Chemistry, Chinese Academy of Sciences
Metal-organic frameworks(MOFs) are a new class of hybrid porous crystalline materials constructed from metal-oxygen clusters with organic linkers, creating three dimensional ordered frameworks. As porous materials, MOFs usually possess very high surface area. The framework topologies and pore size of MOFs can be designed via choosing various metal centers and organic linkers, their chemical properties can be modified by chemical functionalization of linkers and post modification. These unique characteristics make MOFs one of the research hot spots in the fields of chemistry and materials, and they have shown potential applications in various research areas. But there is a crucial weakness which hinders the development of MOFs, namely, the low stability. However, zirconium-terephthalate-based MOF UiO-66 has remarkable hydrothermal stability, the framework is claimed to be stable up to 500 ℃, and it is also highly resistant to many solvents. UiO-66 has gained great attention since the outstanding qualities. In this review, details of the synthesis modulation and functionalization of UiO-66 are presented. In addition, the research actuality and prospective of UiO-66 in the fields of adsorption, catalysis, etc. are also discussed.
We present a brief review of recent progress in materials chemistry based on graphene, including the preparation and surface modification of graphene and graphene-based composites. The composites consisted of graphene and polymers, inorganic particles and other carbonaceous materials are described principally. In addition, the prospective applications of these graphenebased materials have also been briefly introduced.
The effects of non-rare earths impurities, such as Fe, Si, Al on the formation of emulsion phase were studied in the extraction of yttrium with naphthenic acid, and Si was found to be most significant one. Different solutions for removing the feed solutions were provided and an oxidation absorption precipitation method was proven to be the most effective approach, which can remove the emulsion phase in the extraction of rare earths.
The abilities of sodium alkyl aryl sulfonate, which had highpurity and defined structure, to emulsify alkanes, were investigated by a water diversion method. Using liquid paraffin wax as the oil phase, the effects of the concentration of emulsion, length of alkyl chain, structures and locations of aryl groups in alkyl chain on emulsion stability were studied, and the best concentration of emulsion were determined. Meanwhile, the effects of different oil phases to emulsion stability were discussed. The experimental data showed that the best mass fraction of emulsion was 0.1%. With definite structures of aryl group, emulsion stability increased linearly with the increasing of the length of carbonic chain. When the length of alkyl chain on alkyl group was set, the emulsion stability was enhanced with the increasing of the length of alkyl chain on aryl group. With the aromatic ring shifts from the terminal to the center of the long alkyl chain, the emulsion stability increased. With the increase of molecular mass of oil phases, the molecular mass of emulsifier to achieve stable emulsifying liquid increased.
Hexaphenoxycyclotriphosphazene（HPCTP）was synthesized by the reaction of crude hexachlorocyclotriphosphazene（HCCTP） with phenol and sodium hydroxide，with tetrabutylammonium chloride（TBAC） as phase transfer catalyst and chlorobenzene/water as solvent. Effects of reaction temperature， reaction time， solvent and molar ratio of raw materials on the yield of HPCTP were investigated. Under the optimized reaction conditions of n(sodium hydroxide)∶n(phenol)∶n(TBAC)∶n(crude HCCTP)=7.5∶6.3∶0.15∶1， reaction time of 4 h at 30 ℃ plus 6 h at reflux temperature， the yield was 75%. The product was characterized by FTIR， 1H NMR， 13C NMR， 31P NMR， XRD， DSC and TGA. The product has been firstly applied in benzoxazine resin glass cloth laminate. The flammability class of the laminate was in the rank of V-0， the breakdown voltage of the laminate was 47 kV, and the thermal state flexural strength of the laminate was 596 MPa when the mass fraction of HPTCP in the laminate was 10%.
Surface-enhanced Raman spectroscopy(SERS) is a fingerprint spectroscopic technique with ultra-high sensitivity. It has been widely used in surface science, material science, biomedicine, drug analysis, food safety inspection, and pollutant detection, as a promising technique for trace analysis. In this paper, we comprehensively reviewed the development and applications of SERS and related techniques, including tip-enhanced Raman spectroscopy(TERS), shell-isolated nanoparticle-enhanced Raman spectroscopy(SHINERS), and discussed its research frontiers and development directions in the future.
Six different imidazoline quaternary ammonium salts were synthesized with the use of valeric acid, decanoic acid, oleic acid, diethylenetriamine, benzyl chloride and thiourea as raw materials. The corrosion inhibition performances of quaternary ammonium salts of thioureido alkyl imidazoline and alkyl imidazoline on carbon steel in 1.0 mol/L HCl medium were compared at 80 ℃ via both static mass loss and polarization curve methods. The synergies between each of these two corrosion inhibitors and each of the inorganic anions or anionic surfactants were also investigated. The results show that the inhibition effect of quaternary ammonium salt of thioureido alkyl imidazoline reaches a 98.3% rate of corrosion inhibition and is significantly superior to that of quaternary ammonium salt of alkyl imidazoline. The best corrosion inhibition effect is achieved when the mass ratio of quaternary ammonium salt of thioureido alkyl imidazoline to I- is 1∶1 during preparation process. This gives a corrosion inhibition effect 1.5% higher than that of quaternary ammonium salt of thioureido alkyl imidazoline compounds used alone.
A novel conjugated polymer containing azobenzene and 1,3,4-oxadiazole units(LPOXD) was synthesized. The structure of the LPOXD was charactered by FT-IR, UV-Vis, 1H NMR, GPC, TGA and DSC. The results indicate that the intrinsic viscosity of the LPOXD is 0.02960 L/g, and its Mw and molecular mass distribution or polydispersity index(PDI) values are 8500 g/mol and 1.55, respectively. A 5% mass loss of the LPOXD occurred at 290 ℃. The glass-transition temperature(Tg) is 92.8 ℃. The introduction of long side chain of alkoxy significantly improved LPOXD′s solubility in common organic solvents such as chloroform, tetrahydrofuran, and so on. Furthermore, the optical and electrochemical properties of the LPOXD were investigated throughly by UV-Vis absorption spectroscopy, fluorescence emission spectroscopy and cyclic voltammetry. The results indicate that the azobenzene in the LPOXD involve a trans-cis photoisomerization under the radiation of 365 nm UV light. A wide fluorescence peak of the LPOXD appeared in the wavelength range of blue and purple light under excitaion at 350 nm. Cyclic voltammetry reveals that the LUMO and HOMO energies of the LPOXD are -5.96 eV and -3.17 eV, respectively.
Calcium carbonate(CC) with calcite structure was efficiently synthesized using collodion membrane as an active template. Then, the CaCO3/Ni composite was obtained through in situ reaction on the CC surface. The morphologies, structures, and thermal stability of the composite were studied by TEM, XRD, FT-IR and TG-DTA, etc. The composite was added to the antistatic-coating system, which shows the same antistatic ability(electrical resitivity:1.2×106 Ω·cm) as that of Ni powders, and saves about 60% Ni. The composite can be applied in the fields of conductive, antistatic, etc., to replace Ni materials.
Inorganic halide perovskite CsPbX3(X=Cl,Br,I) nanocrystals(NCs) have been received much concern because it owns many excellent optical properties, such as high quantum yield(~90%), the emission wavelength covering the entire visible light region(400~700 nm), and the narrow full width at half maximum(12~42 nm). These advantages make it becomes one of the luminescence materials which have the most potential applications. Therefore, in recent years, reports involving inorganic halide perovskite materials become more and more. In this review, the development history, the synthetic routes, structures, growth mechanisms, and applications of inorganic halide perovskite NCs that make them excellent optoelectronic materials for various strategies are mainly discussed and highlighted. The existing problems of inorganic halide perovskite luminescence materials under the current research backgrounds are summarized. Finally, perspectives on future exploration of inorganic halide perovskite NCs for photoelectric devices are also given.
With substituted azoaromatic diacid and thionyl chloride as starting materials，eight substituted azobenzene diacyl chlorides were first synthesized under ultrasonic irradiation in the absence of catalyst. Compared with conventional heating method, the reaction time was shortened from 12 to 4 h, and the yields were in the range of 80%～95%. The structures of all products were characterized by 1H NMR, IR spectra and elemental analysis.
Four N,N-bis(8-flavonmethyl)geranylamine derivatives were designed and synthesized. The structures of the synthesized compounds were determined from the results of 1H NMR, MS and elemental analysis. The prelimilary cytotoxicity was evaluated on K562 and SMMC7721 cell lines by MTT assay. The results demonstrated that all compounds possessed antitumor actitity and compound 1c is the best among them with an IC50 value of 5.78 μmol/L or 3.85 μmol/L against K562 or SMMC7721 cell lines, respectively. The in vitro antitumor activities of compounds 1a and 1c against K562 were better than that of the commercial drug Melphalan. The interaction of compound 1c with herring sperm DNA was explored with ethidium bromide(EB) as a fluorescence probe. The result of the study on fluorescence quenching by DNAEB confirms the strong interaction of compound 1c with Herring Sperm DNA.
The authors briefly summarized the recent progress of benzo[b]thiophene derivatives used for organic field-effect transistors(OFET), in which two families:ladder-type and star-shape compounds were presented. The synthetic approaches and the properties of polycyclic hydrocarbons for application in OFET were introduced. Benzo[b]thiophene derivatives will become promising candidates as the active materials with high performance in the application of organic electronics.
Hyperbranched Waterborne Polyurethane (HBAPU) was synthesized via A2+bB2 approach using 2,4-toluylene diisocyanate(TDI), polycarbonatediol (PCDL) ,dimethylol propionic acid (DMPA) and diethanol amine (DEOA) as materials. The structure of the products were characterized by FT-IR and 13C NMR. The result showed that the degree of the branching (DB) of the HBAPU increased with the molar ratio of the NCO/OH increased. The properties of the products were measured by PCS, TG, tensile tests ,the water-resistant of the cast films were also investgated.the partical sizes of the HBAPU was 20.57 nm, compareing with that of line aqueous polyurethane with 130.91 nm when the content of DMPA was 0.4 mmol/g,meanwhile, the HBAPU exhibited good water resistant, heat resistance and tensile strength.
Due to simple operation, high resolution and real-time imaging,fluorescence technology has been widely used in detection and bioimaging. The second near-infrared window dyes(NIR-Ⅱ, 10001700 nm) have longer emission wavelength, less interference with light scattering and tissue autofluorescence, resulting in higher temporal and spatial resolution and deeper imaging depth in tissue imaging. In this review, we mainly introduce the designed mechanism and research progress in bioimaging based on NIR-Ⅱ dyes, and further give an outlook in the following studies.
3,5-Diaminopyridine and 3,5-dimethoxycarbonylamino-pyridine were prepared from 3,5-dimethylpyridine in three steps including oxidation of methyl, amination and Hofmann degradation with the total yield of 64% and 68%, respectively. The reaction conditions of every step were studied and the intermediates and target compounds were characterized by 1H NMR, MS/MS, and IR. The reactions proceed under atmosphere pressure with mild reaction conditions, easy post treatment and high efficiency.
Three manganese oxide octahedral molecular sieves(OMS2), K-OMS2, H-K-OMS-2 and Cu-OMS-2, were synthesized according to the literature. The structure and composition of the obtained materials were characterized by SEM and XRD. OMS-2 was applied to the selective oxidation of alcohols to generate corresponding aldehydes or ketones. The effects of reaction time and temperature on the catalytic reactions were investigated in ionic liquid [bmim]PF6 when different OMS-2 materials were used as catalysts. The conversion and selectivity of benzylic or allylic alcohols catalyzed by H-K-OMS-2 both reached over 90%. The solvent and catalyst could be recovered from the reaction system by extraction method and vacuum distillation method respectively. The catalytic system recovered by vacuum distillation method showed better recycling performance.
2,6-Di(2′-imidazoline-2′-yl)pyridine, even though it is not fully aromatic, has the same distribution of heteroatoms as 2,6-di(2′-benzimidazol-2′-yl)pyridine and has been synthesized from pyridine 2,6-dicarboxylic acid and ethylenediamine under microwave irradiation and without catalyst. The composition and structure of the product were identified and characterized by IR, mass spectrometry, 1H NMR, 13C NMR and melting point determination. The ratio of products and byproduct was found to be different under different experimental conditions(solvents, proportion of reacting mass, power of microwave irradiation). Among them, solvents have very obvious effects on the ratio of product and byproduct. The experimental results indicate that the best solvent is ethylene glycol. The optimal reaction condition are follows:molar ratio of raw materials 1∶2.7, microwave power 450 W, irradiation time 65 min, irradiation temperature 130 ℃ and the overall yield 71.2%. The binding of this compound with calf thymus DNA was investigated by UV and viscosity measurements. The binding constant Kb is meaused to be (9.60±0.05)×104 L/mol, which is lower than those observed for typical classical intercalators. The results of viscosity measurement reveal that the presence of 2,6-di(2′-imidazoline-2′-yl)pyridine has no obvious effect on the relative viscosity of DNA. It may bind to DNA by hydrogen bonding and grooveface binding.
Inhibitory effects of two Schiff bases N,N′-bis(salicylidene)-1,2-ethylendiamine(SB-Ⅰ) and salcylidene-pyridine-2-yl-amine(SB-Ⅱ) on the corrosion of carbon steel in 1 mol/L HCl solution were studied via mass loss measurement method, polarization and electrochemical impedance spectroscopy. The results show that compounds SB-Ⅰ and SB-Ⅱ have fairly good inhibiting properties for carbon steel corrosion in hydrochloric acid with the best efficiencies of 85% and 92%, respectively, at 20 mmol/L additive concentration, and they belong to anodic inhibitors.
The applications of polyhydroxyl terephthalic acids in medicines and functional materials have captured much research attentions. This article reviews the synthesis and application of four typical chemicals with utmost importance and value. The preparation process of polyhydroxyl terephthalic acid substances through Koble-Schmitt reaction with phenol-type substances as starting materials has advantages such as simple operation, low production cost and environment benign, and so on.
Graphene oxide (GO) and reduced graphene oxide (RGO) were prepared by modified Hummers method and hydrothermal reduction, respectively. They were characterized by transmission electron microscopy (TEM), UV-Vis absorption spectroscopy (UV-Vis), Fourier transform infrared (FTIR) spectroscopy, and photoluminescence emission and excitation spectroscopy(PL, PLE). PL spectra indicate that the broad near-infrared(NIR) photoluminescence ranging from 600 to 800 nm can be acquired from graphene oxide under excitation of visible light. By comparing PL spectra from GO with that from RGO, and through the analysis of their UV-Vis absorption and FTIR spectra, the oxygen related groups, such as C=O and COOH, are found to be responsible for the NIR PL from GO. NIR fluorescence is favorable for bio-imaging because of its excellent penetrating ability and little damage to tissues. This indictates that GO has great potential applications in bio-imaging.
Five kinds of 4,6-diaryl-2-aminopyrimidine derivatives were synthesized and characterized by IR, MS and 1H NMR. The Escherichia coli methionine aminopeptidase(EcMetAP) inhibitactivities and the CXCR4 receptor antogonists activities of the five compounds were determined. The results show that all the five compounds have the EcMetAP inhibit-activities, and they also have CXCR4 receptor antogonists activities except the compound 2. The structure-activity relationships were studied by the FieldTemplater and FieldAlign software through molecular field analysis. The results show that the pharmacophore could be 3-N atom and 4,6-bencycles used as the EcMetAP inhibitor，and the EcMetAP inhibit-activities could be increased by addition of electron-donating groups at 6-benzyl. It also shows that the pharmacophore could be 2-C atom and 4,6-bencycles used as the CXCR4 receptor antogonists. The CXCR4 receptor antogonists could be increased by addition of electrondonating substituent at 2-C.
Two pyridyl imidazo[4,5-f]1,10-phenanthroline derivates, namely 2-(3-pyridyl)-imidazo[4,5-f]1,10-phenanthroline(G1) and 2-(4-pyridyl)imidazo [4,5-f]1,10-phenanthroline(G2), were synthesized and characterized by elemental analysis, 1H NMR and MS. Under various concentrations of cucurbit[n]urils(Q[n], n=6,7), the interaction of Q[n] with G1 and G2 were studied in buffer solutions with different pH values by using UV-Vis spectroscopy and fluorescence spectrophotometry. The results revealed that cucurbit[n]urils(n=6,7) form a 1∶1 complex with G1, and Q form a 1∶1 complex with G2 in acidic solution, fluorescent sensitizing effects of both Q and Q toward guests were determined. Under acidic solution Q formed a 2∶1 complex with G2, and a fluorescent quenching effect of Q on G2 was observed. Association constants(K) of Q[n](n=6,7) with G1 were found to be 3.00×104 L/mol, 1.86×104 L/mol respectively, while those of Q[n](n=6,7) with G2 are 1.64×104 L/mol and 1.01×103 L/mol respectively. With decreasing acidity of the systems, the interaction between guests and Q[n](n=6,7) weakened and no interaction was observed under neutral conditions.
In order to provide a reference for octenyl succinic anhydride(OSA)-modified starch and methyl oleate used in green pesticide preparations, the formulation of the lambda-cyhalothrin oil-in-water emulsion with OSA-modified starch and methyl oleate as emulsifier and solvent was studied. Furthermore, the effects of different processing parameters, including the concentration of pretreating fluid of OSA-modified starch, rotational speed and shearing time on the stability of emulsion were studied by measuring oil droplet diameter distribution. Results demonstrated that OSA-modified starch had excellent emulsification ability to methyl oleate. High stable emulsions(2.5%) could be prepared with OSA-modified starch. The mean droplet diameters of emulsion were about 1.2 μm, and increased by only 0.1~0.3 μm after storing at 25 ℃ for 6 months or at (54±2) ℃ for 14 days, and approximately 100% of the oil remained stable in the emulsion. Higher stable emulsions could be prepared by emulsification at high viscosity with mass fraction of pretreating fluid of OSA-modified starch in the range of 15%~25%. Smaller oil droplet diameters were obtained when the rotational speed was increased, which had no significant effect on homogeneity of emulsions. On the other hand, an increase of the shearing time reduced the span of oil droplet diameter distribution, but had no significant impact on the mean oil droplet diameter. Lambda-cyhalothrin oil-in-water emulsion prepared with OSA-modified starch had a better stability than the conventional emulsions. The results of this study show that OSA-modified starch and methyl oleate can be used as an effective emulsifier and solvent for the environment-friendly lambda-cyhalothrin oil-in-water emulsion formulations.
A novel dinuclear macrocyclic polyamine Zn(Ⅱ) complex was synthesized from 1,4,7,10-tetraazacyclododecane, the structures of the compounds were characterized by 1H NMR, MS and elemental analysis. The interactions between calf thymus(CT) DNA and these compounds were investigated by fluorometric detection. The fluorescence intensity of the DNA/EB system was decreased to 47.3% of that of the initial system at c(complex 6)/c(DNA)=0.51, which indicates that the dinuclear complex was inserted into the CT DNA. The order of fluorescence quenching values of the DNA/EB systems by these ompounds:dinuclear macrocyclic polyamine Zn(Ⅱ) complexd＞dinuclear macrocyclic polyamine ligand＞CyclenZn(Ⅱ) complex＞Cyclen.
Employing heterogeneous reaction, 6-deoxy-tosyl-β-cyclodextrin(6-OTs-β-CD) was prepared by the reaction of β-CD with p-toluenesulfonyl chloride at low temperature in sodium hydroxide aqueous solution. The compound has been characterized by means of UV-Vis, IR, 1H NMR and 13C NMR spectroscopies. The mechanism of cyclodextrin mono tosylation was confirmed by 1H NMR. The effect of hydrolysis factors on product and the influence of reaction conditions on the yield were investigated. Under optimal reaction conditions molar ratio of reactant n(TsCl)∶n(CD)=4∶1, alkali concentration 0.75 mol/L, mass fraction of reactants 4.7%, reaction temperature 0 ℃ and reaction time 5 h, a yield of 43.4% can be obtained.