Synthesis,crystal structure and magnetic properties of a new tri‐nuclear iron (II,III) complex,a precursor for the preparation of superparamagnetic Fe3O4 nanoparticles applicable in the removal of Cd2+

This study reports the structural and spectroscopic characterization of a novel metal organic compound formulated as [Fe (bpy)₃] [Fe (dipic)₂]₂.7H₂O ( 1 ) (dipic = pyridine‐2,6‐dicarboxylate and bpy = 2,2^′‐bipyridine). 1 was investigated by elemental analysis, FT‐IR spectroscopy, powder X‐ray diffraction and single crystal X‐ray diffraction (SC‐XRD), which revealed a triclinic structure of expected composition. Thermal degradation of 1 was also investigated. Complex 1 was used as a precursor to prepare superparamagnetic nanoparticles of Fe₃O₄ by thermal analysis. The obtained Fe₃O₄ was characterized by Fourier transformed infrared spectroscopy (FT‐IR), powder X‐ray diffraction (XRD) and scanning electron microscopy (SEM). Fe₃O₄ nanoparticles were used as a nano‐adsorbent to remove Cd²⁺ from water at room temperature. The results showed that this nano‐adsorbent is effective in removing Cd²⁺ from contaminated water sources, and that the maximal effectivity of adsorption occurs at pH = 6. Magnetic measurements of complex 1 and Fe₃O₄ nanoparticles at room temperature revealed paramagnetic and superparamagnetic behavior, respectively.     

Cu(II) immobilized on mesoporous organosilica as an efficient and reusable nanocatalyst for one‐pot Biginelli reaction under solvent‐free conditions

Cu(II) immobilized on mesoporous organosilica nanoparticles (Cu²⁺@MSNs‐(CO₂^?)₂) has been synthesized, as a inorganic–organic nanohybrid catalyst, through a post‐grafting approach. Its characterization is carried out by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy dispersive X‐ray (EDX), Thermogravimetric/differential thermal analyses (TGA‐DTA), and Nitrogen adsorption–desorption analysis. Cu²⁺@MSNs‐(CO₂^?)₂ exhibits high catalytic activity in the Biginelli reaction for the synthesis of a diverse range of 3, 4‐dihydropyrimidin‐2(1H)‐ones, under mild conditions. The anchored Cu(II) could not leach out from the surface of the mesoporous catalyst during the reaction and it has been reused several times without appreciable loss in its catalytic activity.     

Reactive adsorption of hydrogen sulfide by promoted sorbents Cu‐ZnO/SiO2: active sites by experiment and simulation

In the Cu_x‐Zn_(1‐x)O/SiO₂ sorbents for ultradeep adsorptive removal of H₂S from gaseous fuel reformates for fuel cells at room temperature, Cu promoter sites significantly increase sulfur uptake capacity of the sorbents. We report characterization of the family of Cu_x‐Zn_(1‐x)O/SiO₂ sorbents for reactive adsorption of H₂S using X‐ray diffraction (XRD), Brunauer‐Emmett‐Teller (BET) surface area analysis, electron spin resonance (ESR), ultraviolet–visible (UV–vis) diffuse reflectance spectroscopy (DRS) and calculations by the density functional theory (DFT). Both the supported ZnO phase and Cu promoter sites in the Cu_x‐Zn_(1‐x)O/SiO₂ sorbents are nano‐dispersed, as shown by XRD. The Cu_x‐Zn_(1‐x)O/SiO₂ sorbents contain Cu promoter as the Cu²⁺ site of octahedral geometry, as found by the complementary ESR and UV–vis DRS. Mechanism of the promoter effect of the Cu²⁺ site in the Cu_x‐Zn_(1‐x)O/SiO₂ sorbents in reaction with H₂S is proposed based on DFT calculations. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis of propyl aminopyridine modified magnetite nanoparticles for cadmium (II) adsorption in aqueous solutions

In this study, 2‐aminopyridine functionalized magnetite nanoparticles were chemically synthesized and used for removing Cd²⁺ ions from aqueous solutions. The synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis of X‐rays (EDX), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM). The SEM results showed the synthesized magnetite nanoparticles have particle size around 26 nm. The effects of several variables including solution pH and volume, adsorbent mass, ionic strength and contact time on the Cd²⁺ adsorption were studied in batch experiments and finally the optimum conditions for adsorption were obtained. The kinetic data were investigated by pseudo‐ first‐order, pseudo‐ second‐order, intraparticle diffusion and Elovich kinetic models and data were described reasonably by pseudo‐ second‐order model (R² = 0.9996) with q_e = 2.31 mg g^?1. Adsorption data were analyzed using Langmuir, Freundlich and Temkin isotherm models. The results indicated that the data were well fitted to the Freundlich isotherm model (R² = 0.9907). After study the possible interference effect of foreign ions on Cd²⁺ removal, the applicability of the proposed nanoparticles for adsorption from real samples confirmed the successfully removal of Cd²⁺ ions with removal efficiency higher than 92%. The obtained results showed that the synthesized nanoparticles as a reusable adsorbent can act as a good choice for Cd²⁺ removal with an easy procedure.     

Polymer complexes. LXXVI. Synthesis,characterization, CT‐DNA binding,molecular docking and thermal studies of sulfoxine polymer complexes

Novel polymer complexes of 8‐hydroxyquinoline‐5‐sulfonic acid hydrate ( H ₂ L ) with Cu²⁺, Co²⁺ and Ni²⁺ chloride were prepared and characterized. Microanalysis, magnetic susceptibility, IR spectra, electron spin resonance, mass spectra, X‐ray, molar conductance, thermal, and UV–Vis spectra studies have been used to confirm the structure of the prepared polymer complexes. The molecular and electronic structures of the hydrogen bond conformers for ligand ( H ₂ L ) were optimized theoretically and the quantum chemical parameters were calculated. On the basis of elemental and IR data, the chemical structure of metal chelates commensurate that the tri‐dentate (H₂L) coordinate to metal chlorides through oxygen atom of phenolic OH and oxygen atom of SO₃‐H group by replacing H atoms and nitrogen of the quinoline ring. The magnetic studies suggested the octahedral geometrical structure for all produced polymer complexes with general formula {[ML (OH₂)₃] .xH₂O}_n (M = Cu²⁺, x = 1.; Co²⁺, x = 2 and Ni²⁺, x = 2) in molar ratio (1:1). Coats–Redfern and Horowitz–Metzger methods have been used for calculating the activation thermodynamic parameters of the thermal decomposition for H ₂ L and its polymer complexes. The interaction between H ₂ L and its transition metal complexes with the calf thymus DNA (CT‐DNA) was determined by UV–Vis spectra. Binding efficiency between H ₂ L with the receptors of the prostate cancer (PDB code 2Q7L Hormone) and the breast cancer (PDB code 1JNX Gene regulation) was studied by molecular docking. The inhibition behaviour of H ₂ L against the corrosion of carbon steel / HCl (2 M) solution was studied by weight loss, Tafel polarisation, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. The adsorption isotherm was found to be Friendlish isotherm. The morphology of inhibited carbon steel? s surface was studied using scanning electron microscope (SEM) and energy dispersive X‐ray spectroscopy (EDS).     

Introduction of organic/inorganic Fe3O4@MCM‐41@Zr‐piperazine magnetite nanocatalyst for the promotion of the synthesis of tetrahydro‐4H‐chromene and pyrano[2,3‐d]pyrimidinone derivatives

Fe₃O₄@MCM‐41@Zr‐MNPs modified with piperazine is easily prepared and characterized using Fourier transform infrared spectroscopy (FT‐IR), X‐ray powder diffraction (XRD), N₂ adsorption–desorption, Transmission electron microscopy (TEM), Energy‐dispersive X‐ray (EDX), Vibrating sample magnetometry (VSM) and Thermogravimetric analysis (TGA) techniques. The characterization results showed that Zr highly dispersed in the tetrahedral environment of silica framework and piperazine is successfully attached to the surface of the nanocatalyst in connection with zirconium. The prepared nanosized reagent (10–30 nm), shows excellent catalytic activity in the synthesis of tetrahydro‐4H‐chromene and pyrano[2,3‐d]pyrimidinone derivatives. All reactions are performed under mild and completely heterogeneous reactions conditions in high yields during short reaction times. On the other hand and due to its superparamagnetic nature the catalyst can be easily separated by the application of an external magnetic field and reused for several times.     

Sucrose chelated auto combustion synthesis of BiFeO3 nanoparticles: Magnetically recoverable catalyst for the one‐pot synthesis of polyhydroquinoline

Sucrose chelated Bismuth ferrite (BiFeO₃) nanoparticles as a novel heterogeneous catalyst was synthesized by an auto combustion route. Different calcination temperatures (150 °C, 450 °C, 550 °C, 650 °C, 750 °C and 850 °C) have been employed to obtain single phased BiFeO₃ nanoparticles. The perovskite structure formation and disappearance of organic phase (sucrose) was obtained by Fourier transform infrared spectroscopy (FT‐IR). Phase determination and structural characterization was carried out by powder X‐ray diffraction (XRD). The magnetic properties were analyzed by vibrating sample magnetometer (VSM) whereas surface area/pore volume was obtained by Brunauer–Emmett–Teller (BET). Transmission electron microscope (TEM) analyzed the particles size and morphology. Thermal stability was investigated by thermogravimetric analysis (TGA) and determination of constituent elements was carried out by X‐ray Photo‐Electron Spectroscopy (XPS). Raman spectroscopy confirmed the perovskite structure of the synthesized materials. The BiFeO₃ nanoparticles so obtained were employed as heterogeneous catalyst for the synthesis of polyhydroquinoline derivatives. All the polyhydroquinoline derivatives were characterized by Fourier transform infrared spectroscopy (FT‐IR) and Nuclear magnetic resonance spectroscopy (¹H NMR). For the very first time ever we have used BiFeO₃ as a recyclable magnetic nanocatalyst in the one‐pot four component cyclization reaction of benzaldehyde, ethylacetoacetate/methylacetoacetate, dimedone/cyclohexane‐1,3‐dione, and ammonium acetate for the synthesis of polyhydroquinoline derivatives without solvent under refluxing conditions to provide excellent yields of products. BiFeO₃ nanocatalyst (without any functionalization/surface coatings) shows easy magnetic separation, recyclability, reusability along with excellent yield of polyhydroquinoline derivatives in an economic and benign way.     

Synthesis of Fe3O4@SiO2@DOPisatin‐Ni(II) and Cu(II) nanoparticles: Highly efficient catalyst for the synthesis of sulfoxides and disulfides

The catalytic activity of two magnetic catalysts Fe₃O₄@SiO₂@DOPisatin‐M(II) (M = Ni, Cu) was investigated in the environmentally green H₂O₂ oxidant‐based oxidation of sulfides to sulfoxides and oxidative coupling of thiols to disulfides. By using these catalysts, various substrates were successfully converted into their corresponding product. These catalysts could also be reused multiple time without significant loss of activity. The physical and chemical properties of the catalysts were determined using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), energy dispersive X‐ray spectroscopy (EDX) and atomic absorption spectroscopy (AAS).     

Magnetic mesoporous polyimide composite for efficient extraction of Rhodamine B in food samples

A core‐shell structured magnetic polyimide composite has been synthesized by the covalent coating of a mesoporous polyimide polymer onto the surface of magnetite nanoparticles. The nanocomposite was characterized by scanning electron microscopy, transmission electron microscopy, N₂ adsorption‐desorption isotherms, X‐ray diffraction, infrared spectroscopy, and vibrating sample magnetometry. The results showed that the prepared composite had a large surface area (306.45 m²/g), a unique pore size (2.15 nm), and strong magnetic properties (45.7 emμ/g), rendering it a promising sorbent material for magnetic solid‐phase extraction. The parameters that affect the extraction efficiency of rhodamine B were optimized with the assistance of response surface methodology. Under the optimal conditions, the developed method has been successfully applied to determine the rhodamine B in food samples. The linearities and limits of detection of rhodamine B in hot pepper, red wine, and chili powder samples were measured. Satisfactory recoveries in the range of 94.8–103.3% with relative standard deviations <5.5% were obtained. Investigation of the adsorption mechanism of magnetic polyimide composite indicated that multiple interactions, including hydrophobic, π‐π, and hydrogen bonding interactions, were involved in the adsorption process.     

Green synthesis of 1,2,3‐triazoles via Cu2O NPs on hydrogen trititanate nanotubes promoted 1,3‐dipolar cycloadditions

Cu₂O nanoparticles supported on hydrogen trititanate nanotubes (Cu₂O/HTNT) catalysts have been efficiently catalyzed the multicomponent synthesis of 1,2,3‐triazoles in water at room temperature from different azide precursors, for example organic halides, sulfonates and anilines. The catalysts were synthesized by hydrothermal & wet‐impregnation methods and was characterized by HR‐TEM, EDS, XRD, XPS, N₂‐adsorption desorption and ICP‐MS analysis. The catalyst could be recycled by centrifugation and reused up to seven cycles. The 1‐benzyl‐4‐(4‐chlorophenyl)‐1H‐1,2,3‐triazole ( 25 ) structure was proven by single crystal X‐ray diffraction studies.     

Glassy carbon electrode modified by new Copper(I) oxide nanocomposite for glucose detection: An electroanalysis study

The Glucose amount of human blood is very vital because in higher levels than allowed value the corporal biological system was hampered. Therefore, in this study, the Cu₂O was deposited on the reduced Graphene oxide (RGO) by polydopamin (PDA) as linker. The new RGO‐PDA‐Cu₂O nanocomposite was deposited on the glassy carbon electrode (GCE) surface after its characterization by UV–Visible, fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), Energy‐dispersive X‐ray (EDX), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) techniques. The electroanalysis of the new electrode was investigated by the cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) methods. The obtained detection limit of glucose (Glu) showed that the deposited GCE by RGO‐PDA‐Cu₂O nanocomposite has a high potential for its diagnosis. In addition, this electrode was applied to the Glu detection as biosensor in real samples in order to utilize in commercial applications.     

On‐surface Synthesis of a Semiconducting 2D Metal–Organic Framework Cu3(C6O6) Exhibiting Dispersive Electronic Bands

A 2D metal–organic framework (2D‐MOF) was formed on a Cu(111) substrate using benzenehexol molecules. By means of a combination of scanning tunneling microscopy and spectroscopy, X‐ray photoelectron spectroscopy and density‐functional theory, the structure of the 2D‐MOF is determined to be Cu₃(C₆O₆), which is stabilized by O–Cu–O bonding motifs. We find that upon adsorption on Cu(111), the 2D‐MOF features a semiconductor band structure with a direct band gap of 1.5 eV. The O–Cu–O bonds offer efficient charge delocalization, which gives rise to a highly dispersive conduction band with an effective mass of 0.45 m_e at the band bottom, implying a high electron mobility in this material.     

Nano NiO/AlMCM‐41, a green synergistic,highly efficient and recyclable catalyst for the reduction of nitrophenols

Highly ordered mesoporous molecular sieves AlMCM‐41 and a new NiO/AlMCM‐41 nanocomposite were synthesized using a sol–gel method. Fourier transform infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX), and N₂ adsorption desorption analyses were used to examine the structure, morphology, size and phase composition of the synthesized NiO/AlMCM‐41 nanocomposites. AlMCM‐41 embedded with NiO nanoparticles was subsequently prepared using different nickel loadings in a direct synthetic route. The results show the successful deposition of NiO nanoparticles onto the framework of AlMCM‐41. AlMCM‐41 provides enormous benefits such as environmentally safe, economic viability and porosity when used as support for NiO nanoparticles. The excellent catalytic activities of AlMCM‐41 and NiO/AlMCM‐41 were investigated for the reduction of nitrophenols (4‐NP, 2‐NP) to aminophenols (4‐AP, 2‐AP) in water at ambient temperature. The best observed performance of reduction of NP with 100% conversion into analogous amino derivatives occurred within 6 min with an estimated rate constant of 0.46 min^?1. The efficiency of reduction was observed to increase as a function of NiO enrichment. The NiO/AlMCM‐41 nanocomposite could be recycled and reused up to five times without noticeable change in its structure and activity. These properties make NiO/AlMCM‐41 nanocomposite an ideal platform to study various heterogeneous catalytic processes which can have application in purification, catalysis, sensing devices, and green chemistry.     

Phosphate uptake behavior and mechanism analysis of facilely synthesized nanocrystalline Zn‐Fe layered double hydroxide with chloride intercalation

Zn‐Fe layered double hydroxide with chloride intercalation (ZFCL) was synthesized by a coprecipitation method at room temperature. ZFCL was characterized by N₂ adsorption‐desorption isotherms, X‐ray diffraction, scanning electron microscope, Zeta‐sizer analyzer, X‐ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The results showed that ZFCL had large surface area and layered structure. The maximum adsorption capacity of ZFCL was 150.6 mg/g at 25°C. That was higher than most other adsorbent which were reported. The kinetic data were described better by the pseudo‐second‐order adsorption kinetic rate model. The adsorption isotherm on the adsorbent was described by Langmuir, Freundlich, and Sips models at pH 6 and followed the fitting order: Sips >Freundlich>Langmuir. Thermodynamic analyses indicated that the phosphate adsorption on ZFCL was endothermic and spontaneous in nature. The sequence of coexisting cations and anions competing with phosphate was Ca²⁺ > Mg²⁺ > Na⁺ and SO₄²⁻ > NO₃⁻ > Cl⁻. ZFCL can be regenerated by the sequential use of NaOH and ZnCl₂. The adsorption capacity remained high as 108.6 mg/g after regeneration of 3 times. The results of zeta potential, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy analyses indicated that the phosphate adsorption mechanisms involved ion exchange, Zn₃(PO₄)₂ precipitation, and the formation of inner‐sphere complex via replacement of surface hydroxyl groups by phosphate.     

Polyelectrolyte brushes as efficient platform for synthesis of Cu and Pt bimetallic nanocrystals onto TiO2 nanowires

A Cu–Pt nanoparticle catalyst supported on TiO₂ nanowires (NWs) was prepared through regenerative counterion exchange–reduction using polyelectrolyte brush as template. Cationic polydimethyl aminoethyl methacrylate brushes were grafted onto TiO₂ NWs. Cu–Pt nanocrystals were produced by anionic counterions CuCl₄^2? and PtCl₆^2? bound with the polymer brush through in situ reduction with NaBH₄ of high density and low polydispersity. The as‐prepared TiO₂ NWs/polymer brush/Cu–Pt was characterized by Fourier transform infrared spectroscopy (FT‐IR spectrometry), X‐ray photoelectron spectroscopy, transmission electron microscopy, and UV–Vis adsorption spectrometry analyses. Results showed that the highly dispersed Cu and Pt nanoparticles were present on the surface of the TiO₂ NWs/polymer brush. The resultant TiO₂ NWs/polymer brush/Cu–Pt exhibited extremely high catalytic activity and reduced p‐nitrophenol at room temperature. Copyright © 2017 John Wiley & Sons, Ltd.     

In Situ Fabrication of Inorganic/Organic Hybrid Based on Cu/Co‐ZIF and Cu2O

We successfully fabricate a well‐defined inorganic/organic hybrid Cu₂O@Cu/Co‐ZIF (ZIF=zeolitic imidazolate frameworks) by use of growth of dual‐metal Cu/Co‐ZIF on the obtained Cu₂O hollow spheres. The key point of the strategy is coupling the in situ self‐sacrificing template. Cu₂O and the coordination of metal ions (Cu⁺ and Co²⁺) with 2‐methylimidazole. This new hybrid was characterized by powder X‐ray diffraction, (scanning) transmission electron microscopy, energy‐dispersive spectroscopy mapping, in situ FT‐IR spectroscopy, UV/Vis diffuse reflection spectroscopy, N₂ sorption measurements, and electron spin resonance. It was evidenced that Cu/Co‐ZIF nanocrystals have been assembled to continuous shells surrounding the Cu₂O cores as well as in the voids between layers and inner pores. Cu₂O@Cu/Co‐ZIF exhibits visible light responsiveness and holds potential as narrow band gap semiconductor and visible photocatalyst.     

Synthesis,Characterization, and Crystal Structure of Three Coordination Polymers from 5‐(Pyridin‐2‐ylmethyl)aminoisophthalic Acid

Three new complexes: [M(L)(H₂O)] [M = Zn ( 1 ), Co ( 2 ), Ni ( 3 ); H₂L = 5‐(pyridin‐2‐ylmethyl)aminoisophthalic acid] were synthesized under hydrothermal conditions at 180 °C and were characterized by elemental analysis, FT‐IR spectroscopy, single‐crystal X‐ray diffraction, and thermogravimetric analysis (TGA). The results of X‐ray diffraction analysis reveal that complexes 1 – 3 are isostructural and crystallize in the monoclinic system with space group P2₁/c. Each of the complexes displays a (3,3′)‐connected two‐dimensional (2D) wave‐like network with (4,8²) topology, within which five‐membered uncoplanar N,N‐chelated metallacycles are shaped. Delicate N–H ··· O and O–H ··· O hydrogen bonding interactions exist in complexes 1 – 3 . Adjacent 2D layers are linked by intermolecular interactions, resulting in the construction of extended metal‐organic frameworks (MOFs) in complexes 1 and 2 .     

Synthesis of graphene oxide supported copper–cobalt ferrite material functionalized by arginine amino acid as a new high–performance catalyst

A novel Cu_0.5Co_0.5Fe₂O₄@Arg–GO catalytic system was successfully prepared by immobilization of copper substituted cobalt ferrite nanoparticles on arginine–grafted graphene oxide nanosheets, in which ferrite moiety acts as an oxidation catalyst and arginine has the role of base catalyst. Also, arginine amino acid was used to modify the surface of graphene oxide nanosheets which the prepared support can improve dispersion and uniform loading of nanoparticles. The prepared nanocomposite was characterized by flame atomic absorption spectroscopy (FAAS), inductively coupled plasma optical emission spectrometer (ICP–OES), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT–IR), ultraviolet–visible spectroscopy (UV–vis), Raman spectroscopy, thermogravimetric analysis (TGA), x–ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analysis. The prepared Cu_0.5Co_0.5Fe₂O₄@Arg–GO nanocomposite was used as an efficient catalyst for one–pot tandem oxidative synthesis of 2–phenylbenzimidazole derivatives in good yields.     

Influence of the preparation conditions of Pd‐ZrO2 and AuPd‐ZrO2 nanoparticle–decorated functionalised MWCNTs: Electron spectroscopy study aided with the QUASES

The Pd, AuPd, and ZrO₂ nanoparticle–decorated functionalised multiwalled carbon nanotubes (f‐MWCNTs) were reported as efficient catalysts of formic acid (FA) electro‐oxidation. Different preparation conditions influence their chemical and structural properties analysed by X‐ray photoelectron spectroscopy aided with the quantitative analysis of surfaces by electron spectroscopy. Different reduction procedures such as NaBH₄, a polyol microwave‐assisted method (PMWA), and a high pressure microwave reactor (HPMWR) were applied for decorating ZrO₂/f‐MWCNTs with Pd and AuPd nanoparticles. The ZrO₂ nanoparticles are attached through oxygen groups to the surface of f‐MWCNTs. In NaBH₄ and HPMWR procedures, Pd nanoparticles precipitate predominantly on ZrO₂ of nearly nominal stoichiometry, whereas in PMWA procedure, Pd and AuPd nanoparticles precipitate predominantly on the surface of f‐MWCNTs, bridging with oxygen groups and ZrO_x (x < 2) and leading to Pd‐O‐Zr phase formation. Strong reducing procedures (NaBH₄ and FA) led to smaller Pd nanoparticle size, Pd oxide content, and PdO_x overlayer thickness in contrary to weak reduction procedures (HPMWR and PMWA). The highest content of Pd‐O‐Zr phase appeared for Pd predominant precipitation on ZrO₂ nanoparticles (HPMWR) in contrary to Pd and AuPd predominant precipitation on surface of f‐MWCNTs (NaBH₄ ~ FA > PMWA). Larger content of Pd‐O‐Zr phase in AuPd‐decorated ZrO₂/f‐MWCNTs in contrary to Pd‐decorated sample (PMWA) could be justified by different electronic properties of nanoparticles. The FA treatment of Pd and AuPd‐ZrO₂/f‐MWCNTs samples provided decreasing Pd oxide content, overlayer thickness, nanoparticle size, increasing nanoparticle surface coverage and density, amount of Pd‐O‐Zr, what results from reduction of oxygen groups bridging with Pd and ZrO_x nanoparticles, also through Pd‐O‐Zr phase.     

Mono‐ and dinuclear CuII complexes of the benzyldipicolylamine (BDPA) ligand: crystal structure,synthesis and characterization

The crystal structures of mono‐ and dinuclear Cu^II trifluoromethanesulfonate (triflate) complexes with benzyldipicolylamine (BDPA) are described. From equimolar amounts of Cu(triflate)₂ and BDPA, a water‐bound Cu^II mononuclear complex, aqua(benzyldipicolylamine‐κ³N ,N′ ,N ′′)bis(trifluoromethanesulfonato‐κO )copper(II) tetrahydrofuran monosolvate, [Cu(CF₃SO₃)₂(C₁₉H₁₉N₃)(H₂O)]·C₄H₈O, (I), and a triflate‐bridged Cu^II dinuclear complex, bis(μ‐trifluoromethanesulfonato‐κ²O :O ′)bis[(benzyldipicolylamine‐κ³N ,N′ ,N ′′)(trifluoromethanesulfonato‐κO )copper(II)], [Cu₂(CF₃SO₃)₄(C₁₉H₁₉N₃)₂], were synthesized. The presence of residual moisture in the reaction medium afforded water‐bound complex (I), whereas dinuclear complex (II) was synthesized from an anhydrous reaction medium. Single‐crystal X‐ray structure analysis reveals that the Cu^II centres adopt slightly distorted octahedral geometries in both complexes. The metal‐bound water molecule in (I) is involved in intermolecular O—H…O hydrogen bonds with triflate ligands and tetrahydrofuran solvent molecules. In (II), weak intermolecular C—H…F(triflate) and C—H…O(triflate) hydrogen bonds stabilize the crystal lattice. Complexes (I) and (II) were also characterized fully using FT–IR and UV–Vis spectroscopy, cyclic voltammetry and elemental analysis.