X-ray peak profiling,optical parameters and catalytic properties of pure and CdS doped ZnO–NiO nanocomposites

Russian Journal of Applied Chemistry - In the current study, XRD peak profile analysis, optical and catalytic properties of pure ZnO–NiO and CdS doped ZnO-NiO nanocomposites were...     

Experimental and Computational Studies on the CH Amination Mechanism of Tetrahydrocarbazoles via Hydroperoxides

The acid‐catalyzed reactions of photochemically generated tetrahydrocarbazole peroxides with anilines have been studied experimentally and computationally to identify the underlying reaction mechanism. The kinetic data indicate a reaction order of one in the hydroperoxide and zero in the aniline. Computational investigations using density functional theory support the experimental findings and predict an initial tautomerization between an imine and enamine substructure of the primarily generated tetrahydrocarbazole peroxide to be the rate controlling step. The enamine tautomer then loses hydrogen peroxide upon protonation, generating a stabilized allylic carbocation that is reversibly trapped by solvent or aniline to form the isolated products.     

Effect of particle size distribution on magnetic behavior of nanoparticles with uniaxial anisotropy

The effect of particle size distribution on the field and temperature dependence of the hysteresis loop features like coercivity(H_C), remanence(M_R), and blocking temperature(T_B) is simulated for an ensemble of single domain ferromagnetic nanoparticles with uniaxial anisotropy. Our simulations are based on the two-state model for T T_B and the metropolis Monte-Carlo method for T T_B. It is found that the increase in the grain size significantly enhances H_C and T_B. The presence of interparticle exchange interaction in the system suppresses H_C but causes MRto significantly increase.Our results show that the parameters associated with the particle size distribution(D_(d,δ)) such as the mean particle size d and standard-deviation δ play key roles in the magnetic behavior of the system.     

Entangled coherent states for quantum information processing

Entangled coherent states (ECSs) with relative phase equal to the phase shift between two coherent states are constructed. We study the degree of entanglement and the nonclassical features exhibited by the so-constructed states keeping in view their role in quantum information processing (QIP).     

双金属镍-锰/γ-Al2O3催化剂对甲烷二氧化碳重整反应的影响 (cited: 1)

用浸渍法制备γ-Al₂O₃负载的Ni-Mn双金属催化剂．在500～700 oC按照17:17:2的CO₂/CH₄/N₂比例,以36 mL/min的载气流速进行甲烷二氧化碳重整反应, 利用甲烷二氧化碳的转化率、生成的合成气H₂/CO比例以及长期稳定性等指标评价了催化剂的催化性能． 实验表明, 添加Mn提高催化性能并使双金属催化剂的稳定性更高, 比单金属催化剂更好地抑制焦炭生成,Mn最合适的添加量0.5wt％ ．通过BET、CO2-TPD、TGA、XRD、SEM、EDX和FTIR各种技术对催化剂进行了表征．     

Easy preparation of 1,4,5-trisubstituted 5-(2-alkoxy-1,2-dioxoethyl)-1,2,3-triazoles by chemoselective trapping of copper(I)–carbon bond with alkoxalyl chloride

We found that alkoxalyl chloride (ClCOCO₂R) did not carry out an acylation on 1-copper(I) alkyne in solvent without additives, but chemoselectively on 5-copper(I) 1,2,3-triazole (an intermediate in cycloaddition of 1-copper(I) alkyne and azide). Thus, a one-pot preparation of 1,4,5-trisubstituted 5-(2-alkoxy-1,2-dioxoethyl)-1,2,3-triazole was achieved by simply stirring the mixture of 1-copper(I) alkyne, azide, and alkoxalyl chloride at room temperature for 4 h.     

Effect of Nano‐support and Type of Active Metal on Reforming of CH4 with CO2

Two series of Co and Ni based catalysts supported over commercial (ZrO₂, CeO₂, and Al₂O₃) nano supports were investigated for dry reforming of methane. The catalytic activity of both Co and Ni based catalysts were assessed at different reaction temperatures ranging from 500—800 °C; however, for stability the time on stream experiments were conducted at 700 °C for 6 h. Various techniques such as N₂ adsorption‐desorption isotherm, temperature‐programmed reduction (H₂‐TPR), temperature‐programmed desorption (CO₂‐TPD), temperature‐programmed oxidation (TPO), X‐ray diffraction (XRD), thermogravimetric analysis (TGA) were applied for characterization of fresh and spent catalysts. The catalytic activity and stability tests clearly showed that the performance of catalyst is strongly dependent on type of active metal and support. Furthermore, active metal particle size and Lewis basicity are key factors which have significant influence on catalytic performance. The results indicated that Ni supported over nano ZrO₂ exhibited highest activity among all tested catalysts due to its unique properties including thermal stability and reducibility. The minimum carbon deposition and thus relatively stable performance was observed in case of Co‐Al catalyst, since this catalyst has shown highest Lewis basicity.     

New N‐(Aryl)‐5‐((quinolin‐8‐yloxy)methyl)‐1,3,4‐oxa/Thiadiazol‐2‐amines and 4‐Aryl‐5‐((quinolin‐8‐yloxy)methyl)‐2H‐1,2,4‐triazole‐3(4H)‐thiones,Synthesis and Characterization

In this study, methyl 2‐(quinolin‐8‐yloxy) acetate ( 2 ) obtained by reaction of 8‐hydroxyquinoline ( 1 ) with methyl chloroacetate was condensed with hydrazine hydrate to afford the carbohydrazide ( 3 ). Thio/semicarbazide derivatives ( 4a , 4b , 4c , 4d , 4e , 4f , 4g ) were obtained by treatment of the 3 with substituted phenyl iso/thioisocyanates. The 4a , 4b , 4c , 4d , 4e , 4f , 4g on acidic and basic intramolecular cyclization led to N‐(aryl)‐5‐((quinolin‐8‐yloxy)methyl)‐1,3,4‐oxa/thiadiazol‐2‐amines ( 5a , 5b , 5c , 5d , 5e , 5f , 5g ) and 4‐aryl‐5‐((quinolin‐8‐yloxy)methyl)‐2H‐1,2,4‐triazole‐3(4H)‐thiones ( 6a , 6b , 6c , 6d , 6e , 6f , 6g ), respectively. All the synthesized compounds were characterized by spectroscopic techniques and elemental analyses. The thiosemicarbazide ( 4c ) was also confirmed by X‐ray crystallography.     

Orange Peel Derived C‐dots Decorated CuO Nanorods for the Selective Monitoring of Dopamine from Deboned Chicken

A novel electrode based on orange peel derived C‐dots decorated CuO nanorods (CR@C‐dot) modified lead pencil (LP) electrode has been fabricated for highly sensitive and selective monitoring of dopamine (DA). Prior to the functionalization with C‐dot, electrochemical efficacy of CR was evaluated and compared with CuO nano‐needles (CN) and nano‐spheres (CS). The morphology, surface area and composition of synthesized nanoparticles was confirmed through field emission scanning electron microscopy (FE‐SEM), N₂‐adsorption‐desorption isotherm, X‐ray diffraction (XRD), Raman spectroscopy and X‐ray photoelectron spectroscopy (XPS). Our results indicated that CR has high electrocatalytic activity compared to CN and CS by expositing greater fraction of catalytic active sites, large surface area and short diffusion pathways. The electrochemical efficacy of CR is further enhanced by decorating with orange peel derived C‐dots, which surprisingly lead to the integrations of surface‐active sites with current collectors with minimum resistance by acting as an electron transport mediator and providing more surface defects. The developed CR@C‐dot sensor enables highly sensitive and selective recognition of DA detection (0.0007 μM), over good linear range (5–2250 μM) with rapid response time. the developed CR@C‐dot sensor was successfully used to monitor the DA from deboned chicken, thus suggesting reliability of the developed electrode.