Copper doped nickel aluminate: Synthesis,characterisation, optical and colour properties

Novel environment friendly inorganic nano green pigments, Ni_1-xCu_xAl₂O₄ (x=0, 0.02, 0.04, 0.06, 0.08, 0.1) were successfully synthesised by simple, cost effective sol-gel method using citric acid as a gelling agent. Synthesised nano pigments were characterised by powder XRD, FT-IR, UV-DRS, SEM-EDX and TEM. Distribution of elements such as Ni, Cu, Al and O for the pigment Ni_0.98Cu_0.02Al₂O₄ was authenticated by elemental mapping analysis. The colour parameters were studied using CIE-LAB parameters. It is evident from the DRS measurement that the band gap energy of NiAl₂O₄ (3.11 eV) has been massively diminished to 2.63 eV when x=0.02, unexpectedly changed the colour of the pigment from cyan to green. Whilst x=0.1 the pigment colour has turned into grey and the corresponding band gap condensed into 2.17 eV. Effect of mineralisers like NaF, CaF₂, NH₄H₂PO₄ and Li₂CO₃ on the colour of Ni_0.98Cu_0.02Al₂O₄ was investigated.     

4,4'-二胺基-2,2',6,6'-四甲基二苯基环己烷的合成与纯化

在浓盐酸中由环己酮和２,６－二甲基苯胶一步合成了多取代基的４,４＇－二胺基－２,２＇,６,６＇－四甲基二苯基环己烷。报道了该二胺的纯化,井使用元素分析、红外光谱、核磁共振谱等分析手段对其进行了表征。     

介孔SO_4~(2-)/ZrO_2的制备、表征及性能

以正丙醇锆为锆前躯体,硫酸铵为硫源,十六烷基三甲基溴化铵(CTAB)为模板剂,溴化钾为添加剂,按n(Zr4+)∶n(CTAB)∶n(SO24-)=2∶1∶2,在水热条件、酸性介质中合成了介孔ZrO2/SO24-。通过X射线衍射(XRD),N2物理吸附,扫描电镜(SEM),FTIR分析手段对其结构进行了表征;并以乙酸正丁酯的酯化反应为探针反应,考察了其催化活性。结果表明,采用两步焙烧法去除模板剂后,该样品的介孔结构类似于MCM-41,d值为3.85nm;在500℃焙烧后,该样品仍具有274m2/g的比表面积及3.2nm的平均孔径;SEM显示焙烧后的样品形貌为球形颗粒;FTIR分析得出,焙烧产物ZrO2/SO42-中S=O键对Zr4+有强的吸电子作用,产生强的Lewis酸中心。当催化剂用量为正丁醇质量的2.5%,n(乙酸)∶n(正丁醇)=1∶2,反应3h后,乙酸的转化率达91.48%。     

N，N，N-三（2-甲基苯并咪唑）胺氧钒配合物的合成、表征及光谱性质研究

本文用微波法合成了配体N,N,N-三（2-甲基苯并咪唑）胺,并以无水甲醇为溶剂,在常温条件下合成了配体与硫酸氧钒的配合物。通过红外光谱和元素分析对其结构进行了表征,并对其紫外吸收峰随pH值的变化及荧光性质进行了研究,结果表明配体在紫外光区吸收峰的强度随pH值的增大而降低,而配合物吸收峰的强度随pH值的增大先降低后增高,二者均发生红移;氧钒配位后使配体发生荧光猝灭。     

N,O-Diarylation of N-Hydroxycarbamates. Rearrangement and Cleavage Reactions of the Intermediate N,O-Diarylhydroxylamines

The reactions of benzyl N-hydroxycarbamate with 2- and 4-nitrofluorobenzene yielded the corresponding benzyl N-(nitrophenoxy)carbamates. Their reaction with nitrofluorobenzenes yielded derivatives of biphenyl and of diphenyl ether. The formation of these products has been rationalized by assuming the existence of N,O-diphenylhydroxylamines as intermediates which undergo rearrangement analogous to the benzidine rearrangement.     

Synthesis,formation and characterisation of FeNbO4 powders

A modified mixed oxide synthetic route has been developed for the synthesis of iron niobate, FeNbO₄ (FN). A rapid vibro-milling technique was employed, with the formation of FeNbO₄ phases investigated as a function of calcination temperature and dwell time by XRD and DTA. The particle size distribution of the calcined powder was determined by laser diffraction techniques, and the morphology, phase composition and crystal structure determined via SEM, TEM and EDX. It has been found that the unreacted Fe₂O₃ and FeNb₂O₆ phases tend to form together with FeNbO₄, with the latter appearing in both monoclinic and orthorhombic phases, depending on calcination conditions. It is seen that optimisation of calcination conditions can lead to a 100% yield of FeNbO₄ in an orthorhombic, α -PbO₂-type phase.     

Equilibrium Adsorption Studies of CO2, CH4, and N2 on Amine Functionalized Polystyrene

Adsorption of CO₂, CH₄, and N₂ has been investigated using amine functionalized polymeric resins having diethanolamine, imidazole, dimethylamine, and N-methyl piperazine covalently attached to the styrene-divinyl benzene copolymer (PS) matrix. The equilibrium adsorption of CO₂, CH₄, and N₂ was examined on these functionalized polymers at pressures from atmospheric to 40 atm for CO₂ and N₂ while up to 10 atm for CH₄ at 303 K. PS-Imidazole showed the highest adsorption capacity for CO₂ as compared to other functionalized polymers. No significant uptake of CH₄ and N₂ was observed at low pressures by any of the functionalized polymers. The adsorption isotherms were analyzed using dual mode sorption model and Ideal Adsorbed Solution Theory (IAST).     

（TAGH）ClO4的结构、热力学及感度性能

以三氨基胍和高氯酸为原料,合成了三胺基胍高氯酸盐(TAGH)ClO_4).利用X-射线单晶衍射仪测定了其晶体结构.结果表明,晶体属于单斜晶系,空间群为P2(1)/c,晶胞参数为a=1.021 3(11)nm,b=1.486 9(15)nm,c=1.093 6(11) nm,β=102.91(2)°.该化合物的分子式为CH_9ClN_6O_4是由三胺基胍离子和高氯酸根结合形成的离子化合物,分子中含有大量的氢键.利用元素分析、红外光谱、DSC、TG-DTG等方法对标题化合物的组成和热力学行为进行了表征,结果表明,在10 ℃/min线性升温速率下标题化合物在457.03℃时质量损失达到99.7%.感度实验结果表明,标题化合物具有较低的摩擦感度,在撞击和火焰作用下均不发火.     

逆向浸取法制取硫酸镁、氢氧化镁及氧化镁

介绍了以硫酸铵、白云石为原料制备硫酸镁、氢氧化镁、轻质氧化镁的实验条件及工艺过程。讨论了实验条件对产品质量、性能的影响。与白云石的开发利用其它工艺比较，该方法具有原料来源方便、生产成本较低等优点，无三废污染，废渣可加工成CaSO4产品，所排氨气也可回收利用。     

吡啶盐染料DEHSPI的合成、结构与光物理性质

合成了一种新型吡啶盐染料4-［4-（N,N-二乙胺基）-2-羟基-苯乙烯基］-N-甲基吡啶碘盐（DEHSPI〖HTSS〗）。用X射线衍射方法测定了其晶体结构,DEHSPI单晶属于单斜晶系,C2/c空间群。晶胞参数：a=3.5970（4）nm,b=1.16270（15）nm,c=2.2081（3）nm,β=114.341（7）°,V=8.4139（18）nm3,Z=8,F（000）=3632,μ=1.536 mm-1,Dc=1.417 g·cm-3,R=0.0501。DEHSPI〖HTSS〗与没有羟基取代化合物的晶体结构分析比较发现,分子中2-羟基基团的存在提高了分子阳离子骨架的平面性。研究了它在不同溶剂和聚合物浸泡的溶胶-凝胶复合玻璃基质中的光物理性质,发现在复合玻璃基质中的荧光强度相对于溶液中大大增强,即使掺杂浓度较高时也没有因生成分子的聚集体而发生明显的荧光猝灭,材料的稳定性提高。     

Solid-phase synthesis, characterization, and antibacterial activities of metallocene-peptide bioconjugates

This work shows how the introduction of an organometallic group enhances and modifies the specificity of biologically active peptides. Ferrocene was chosen as an organometallic group because it has been shown to alter the pharmacodynamic profile of bioactive compounds. A comparison with the isosteric cobaltocenium group allows one to explore the influence of charge and redox potential on the biological activity of the conjugates. Arginine and tryptophan containing peptides H-WRWRWR-NH(2) and H-RWRWRW-NH(2) and the metallocene peptide bioconjugates [M]-C(O)-RWRWR-NH(2) and [M]-C(O)-WRWRW-NH(2), where [M]=[Co(Cp)(C(5)H(4))](+), [Fe(Cp)(C(5)H(4))] were prepared by solid-phase peptide synthesis (SPPS). They were purified by HPLC, characterized by ESIMS and NMR spectroscopy, and tested for antibacterial properties against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus using the minimum inhibitory concentration (MIC) test. In most cases, no metal-specific activity could be observed. However, the conjugate [Fe(Cp)(C(5)H(4))-C(O)-WRWRW-NH(2)] 6 was found to be particularly effective against the Gram-positive S. aureus. The activity of this metallocene-pentapeptide conjugate (7.1 microM) was even better than the 20 amino acid naturally occurring pilosulin 2, which was used as a positive control. Unlike all other compounds tested, which were most active against the Gram-negative E. coli strain, the ferrocene conjugate 6 was the only compound in this series that was most active against Gram-positive bacteria. Given the health concerns resulting from multidrug resistant S. aureus strains, the incorporation of metallocenes may provide a novel line of attack.     

Synthetic, biochemical, antifertility and antiinflammatory aspects of manganese and iron complexes

Manganese(II) and iron(II) macrocyclic complexes of polyamide groups have been synthesized by the template codensation of diamines (2,6 diaminopyridine, 1,2 phenylenediamine and 1,3 phenylenediame) and triamine (diethylenetriamine) with phthalic acid in 1:2:2 molar ratios. On the basis of elemental analysis, IR, electronic, magnetic moment, M?ssbauer, mass and X-ray spectral studies, octahedral structure has been assigned to [M(N4macn)Cl2] (M = Mn(II) and Fe(II), n = 1 to 4) complexes. The complexes have been screened in vitro against a number of fungi and bacteria to assess their growth inhibiting potential. An attempt has been made to correlate the structural aspects of the compounds with their antiinflammatory and antifertility activities.     

6-羟基-2-萘磺酸铜、镁、锌、钴、镍配合物的合成和结构表征

6-羟基-2-萘磺酸钠分别和CuSO4,MgSO4,ZnSO4、Co(phen)3Cl2反应,物质的量比为5∶1,得到一系列铜、镁、锌、钴、镍配合物并通过红外和元素分析确定结构。测定了钴的配合物的单晶结构,结果表明,钴配合物1属于三斜晶系,P-1空间群,a=12.4120(15),b=12.4711(16),c=20.090(2),α=90.0450(10)°,β=103.161(2)°,γ=113.519(2)°,V=2761.9(6)3,Z=2。     

对氟苯甲醛缩乙醇胺席夫碱合成、表征及抑菌活性的测试

通过对氟苯甲醛与乙醇胺的反应，合成了对氟苯甲醛缩乙醇胺席夫碱，并对其进行了元素分析、核磁共振氢谱、红外光谱、紫外光谱表征。抑菌实验表明，该席夫碱对金黄色葡萄球菌和革兰氏阴性菌均有较好的抑制作用。     

Inversion,chemical complexity,and interstitial transport in spinels

Spinels with the generic chemical formula AB₂O₄ have potential applications in nuclear energy and batteries. In both cases, their functionality is related to mass transport through the crystal. Here, using long-time atomistic simulations, we examine the impact of the cation structure on interstitial transport in two spinel chemistries, inverse MgGa₂O₄ and double MgAlGaO₄. We emphasize two aspects of the transport properties: the unit mechanisms that are described by individual barriers, for which we introduce pole-figure-like plots, and the aggregate behavior of those unit mechanisms. Compared to previous work on normal spinels, we find that inversion significantly reduces the rate of interstitial transport in these structures and has an impact on the stability of defects as they move through the lattice. In particular, B cation interstitials are found to be kinetically stable only in the inverse MgGa₂O₄. These results provide new insight into relationship between structure, chemistry, and transport in spinels.     

Synthesis, Cruzain docking, and in vitro studies of aryl-4-oxothiazolylhydrazones against Trypanosoma cruzi

Research in recent years has demonstrated that the Trypanosoma cruzi cysteine protease cruzain (TCC) is a valid chemotherapeutic target. Herein we describe a small library of aryl-4-oxothiazolylhydrazones that have been tested in assays against T. cruzi cell cultures. The docking studies carried out suggest that these compounds are potential ligands for the TCC enzyme. The most promising compound of this series, N-(4-oxo-5-ethyl-2'-thiazolin-2-yl)-N'-phenylthio-(Z)-ethylidenehydrazone (6 f), was shown to be very active at non-cytotoxic concentrations in in vitro assays with mammalian cells and has a potency comparable with reference drugs such as nifurtimox (Nfx) and benznidazole (Bdz).     

Preparation,dielectric property and microwave absorption property of Cu doped SiC nanopowder by combustion synthesis

Abstract

Cu doped SiC nanopowders have been prepared via combustion synthesis, using silicon powder and carbon black as the raw materials, copper powder as the doping source and polytetrafluoroethylene as the chemical activator respectively. The microstructure of prepared nanopowders has been characterised by X-ray diffraction and scanning electronic microscope. The electric permittivities of prepared SiC nanopowders in the frequency range of 8·2–12·4 GHz have been determined. Results show that prepared β-SiC nanopowders have fine spherical particles and narrow particle size distribution, and a quantity of SiC whisker increases with increasing Cu doping content. The Cu₃Si impurity has been generated when Cu content is up to 10%. The β-SiC doped with 10% Cu has the highest real part ?′ and dielectric loss tanδ values. The 5% Cu doped SiC nanopowder with matching thickness of 2 or 2·5 mm exhibits the best microwave absorption properties in the frequency range of 8·2–12·4 GHz.     

New Unsymmetrically Benzene-Fused Bis (Tetrathiafulvalene): Synthesis,Characterization, Electrochemical Properties and Electrical Conductivity of Their Materials

The synthesis of new unsymmetrically benzene-fused bis (tetrathiafulvalene) has been carried out by a cross-coupling reaction of the respective 4,5-dialkyl-1,3-dithiole- 2-selenone 6–9 with 2-(4-(p-nitrophenyl)-1,3-dithiole-2-ylidene)-1,3,5,7-tetrathia-s-indacene- 6-one 5 prepared by olefination of 4-(p-nitrophenyl)-1,3-dithiole-2-selenone 3 and 1,3,5,7-tetrathia-s-indacene-2,6-dione 4. The conversion of the nitro moiety 10a–d to amino 11a–d then dibenzylamine 12a–d groups respectively used reduction and alkylation methods. The electron donor ability of these new compounds has been measured by cyclic voltammetry (CV) technique. Charge transfer complexes with tetracyanoquino-dimethane (TCNQ) were prepared by chemical redox reactions. The complexes have been proven to give conducting materials.     

Removal of Co, Cs, and Zr radioisotopes from aqueous solutions using cellulose iminodiacetic acid chelating cum cation-exchanger

The iminodiacetic acid group containing resin acts as a chelating ion exchanger as well as a weakly acidic cation exchanger, depending upon the species present in the solution. Iminodiacetic acid group has been incorporated onto cellulose by a modified Porath's method of functionalization of polysaccharides. The resin has been used for removal of ⁵⁸Co, ¹³⁴Cs, and ⁹⁵Zr radioisotopes from their separate aqueous solutions. ⁹⁵Zr as [Zr(OH)₂(H₂O)₄]⁸⁺ tetrameric species is adsorbed from the aqueous solution at low pH through cation exchange cum chelate formation. ⁵⁸Co as Co²⁺ is complexed with the resin. ¹³⁴Cs as Cs⁺ is exchanged with equivalent amount of H⁺ ions. Cs⁺ was eluted from resin using 0.3N HCl, Co²⁺ with 4N HCl and Zr(IV) with 5N HCl. Final disposal of the resin can be done by encapsulation in the cement concrete.     

M2(Si,Al)4(N,C)7 (M=La,Y,Ca) carbonitrides: I. Synthesis and structural characterisation by XRD and NMR

A series of new nitrides and carbonitrides has been identified with crystal structures similar to those of the hexagonal quaternary nitrides of the type (Ba,Sr,Eu)YbSi₄N₇. The large divalent cations in these structures can be replaced by trivalent cations such as Ln and/or Y, if valency balance is preserved by the simultaneous substitution of carbon for nitrogen in the unique [4]-coordinated anion site. This has been demonstrated by carbon-13 magic-angle spinning NMR spectra which for the yttrium member of this series shows a peak at 36.7 ppm corresponding to carbon atoms occupying the central non-metal atom site in the characteristic [C(NSi₃)₄] structural unit. The resulting compounds have compositions of the types La₂Si₄N₆C, Y₂Si₄N₆C or (La,Y)₂Si₄N₆C; the crystal structure of a related mixed (Ca,Y) derivative of composition (Ca,Y)₂Si₄(N,C)₇ is reported in Part II of this series. When the two large cations are different, the hexagonal symmetry characteristic of the (Ba,Sr,Eu)YbSi₄N₇ compounds is maintained; when both cations are the same, lower symmetries are observed. The powder diffraction pattern of La₂Si₄N₆C indexes on an orthorhombic unit cell with a=6.0360(7), b=10.1246(9), c=10.5664(11) Å and the crystal structure has been determined. An alternative way of achieving valency balance without incorporation of carbon is to replace some of the silicon by aluminium; related derivatives of the type M₂Si₃AlN₇, where M=La, Y or mixed La,Y have been prepared and their unit cell dimensions are reported.