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In this work, the nearly pure hexagonal phase of lanthania nanoparticles (NPs) was successfully synthesized using three methods: microwave, sol–gel, and hydrothermal. The samples were characterized using nine techniques including powder X-ray powder diffraction, thermogravimetry, transmission electron microscopy, scanning electron microscopy, field emission microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, far infrared spectroscopy, and ultraviolet–visible absorption spectroscopy. This study showed that the method of synthesizing lanthania NPs can affect the size, which in turn has impact on structural, morphological, and optical properties.

[Fe3O(OOCH)6(H2O)3]OOCH·HCOOH, and [Cr3O(OOCH)6(H2O)3]OOCH·2.5HNO3 were synthesized and the molecular structure and vibrational assignments of their cations were investigated by means of density functional theory (DFT) calculations. The harmonic vibrational frequencies of [Fe3O(OOCH)6(H2O)3]+ and [Cr3O(OOCH)6(H2O)3]+ were obtained at the UB3LYP level using a series of basis sets. The topological properties of the charge distribution of both cations in their ground states are discussed in detail by means of natural bond orbital (NBO) theory and of [Fe3O(OOCH)6(H2O)3]+ by the quantum theory of atoms in molecules (AIM). The calculated geometrical parameters and vibrational frequencies were compared with the experimental results. The scaled theoretical frequencies and the structural parameters were found to be in good agreement with the experimental data.

The perovskite-type LaFe 0.9 Co 0.1 O 3 (LFCO1) and LaFe 0.1 Co 0.9 O 3 (LFCO2) nanoparticles (NPs) were prepared via sol–gel method. The structure and morphology of NPs were characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), scanning tunneling microscopy (STM), energy dispersive X-ray spectroscopy (EDX), and Brunauer–Emmett–Teller (BET). The average particle size of NPs is approximately between 20 and 40 nm. The ability of calcined NPs to remove vitavax as a typical pesticide in aqueous solutions was assessed. The removal kinetic studies were conducted on LFCOs NPs with different contact time, temperatures, initial pesticide concentrations, and adsorbent doses to find the optimum conditions. The results showed both NPs can remove the vitavax from aqueous solution with a very high adsorption capacity. The removal process follows first-order kinetics and the Langmuir adsorption isotherm model. The activation energy and Arrhenius factor were obtained from temperature dependence of the rate constant. The thermodynamic parameters of the adsorption were also determined.

Highlights: ► Fabrication of nano Delafossite LiCo{sub 0.5}Fe{sub 0.5}O{sub 2} by sol–gel method. ► Kinetic study of the adsorption properties. ► Removal of reactive blue 5 (RB5) as a reactive dye by the prepared new nanocatalyst. - Abstract: In this paper, nanoparticles of delafossite-type LiCo{sub 0.5}Fe{sub 0.5}O{sub 2} were prepared by sol–gel method in the presence of maleic acid as a chelating agent. The nanoparticles were characterized using differential thermal analysis, X-ray powder diffraction, Fourier infrared spectroscopy, transmission electron microscope, scanning electron microscopy and scanning tunneling microscopy. The nanoparticles showed the excellent adsorption properties towards reactive dye, reactive blue 5 (RB5). The adsorption studies were carried out at different pH values, various adsorbent dosages and contact time in a batch experiments. The kinetic studies indicate that the removal process obeys the second-order kinetic equation. Also, the isotherm evaluations reveal that the adsorption of RB5 by the nanoparticles follows the Freundlich model.

The nano-sized Co2CrO4 spinel was produced for the first time by thermal decomposition of Cr–Co gel prepared by sol–gel method. It was shown that well-crystallized spinel structure is formed after calcination at 450 °C. The usual characterizations were performed and the results showed the particle size of the prepared spinel is 9 nm. Moreover, the prepared nano-sized Co2CrO4 spinel was applied in a simple, efficient and recyclable method for selective oxidation of sulfides to their corresponding sulfoxides with aqueous hydrogen peroxide in tert-butanol.

In this paper, nanospinels NiMnxFe2−xO4 (x = 0.05, 0.1, 0.3, 0.5, 0.7, and 1) were prepared by sol–gel method in the presence of nitrate–metal–ethylene glycol (EG) polymerized complex. The nanospinels were characterized using thermogravimetry analysis (TGA), X-ray powder diffraction (XRD), Fourier infrared spectroscopy (FTIR), and transmission electron microscope (TEM). The adsorption of an azo dye, reactive blue 5 (RB5), from water was determined using the prepared nanospinels. The effect of operational parameters such as the initial dye concentration, the concentration of nanospinels, temperature, and pH on the degradation of dye was investigated. The adsorption process follows second-order kinetics and Arrhenius behavior. Two common models, the Langmuir and Freundlich isotherms were used to investigate the interaction of dye and nanospinels. The isotherm evaluations revealed that the Freundlich model provides better fit to the experimental data than that of the Langmuir model. The photocatalytic degradation of RB5 at pH 1 under UV irradiation was examined. The results showed that the degradation of RB5 dye follows merely an adsorption process.

In the present study, nanoparticles of perovskite-type La0.5Ca0.5NiO3 − δ (LCNO) were fabricated by sol–gel method in the presence of nitrate–metal–ethylene glycol (EG) polymerized complex. A series of analytical techniques were used to characterize the crystallinity, morphology, specific surface area and grain size of La0.5Ca0.5NiO3 powders. Thermal decomposition process of the complex precursor was examined by means of differential thermal analysis–thermal gravimetric analysis (DTA/TGA). X-ray diffraction (XRD) results showed that single perovskite phase has been completely formed after calcination at 750 °C. In addition, transmission electron microscopy (TEM) images revealed that the average size of the particles is approximately 10–32 nm in diameter. The surface morphology and composition of these nanopowders were also investigated using scanning tunneling microscopy (STM), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDX). LCNO nanoparticles showed the excellent adsorption efficiency towards reactive blue 5 (RB5) as a reactive dye in aqueous solution. The adsorption studies were carried out at different pH values, dye concentrations, various adsorbent dosages and contact time in a batch experiments. The dye removal efficiency was found to be decreased with increasing in initial pH of dye solution, and LCNO exhibited good dye removal efficiency at acidic pH specially pH 2. Experimental results indicated that the adsorption kinetic data follow a pseudo-second-order rate for tested dye. The isotherm evaluations revealed that the Langmuir model attained better fits to the experimental equilibrium data than the Freundlich model. Finally, the photocatalytic degradation of RB5 using LCNO under solar light and UV irradiation at pH 2 was also investigated. The results showed that the nanoparticles cannot act as pure photocatalyst and the degradation of RB5 dye follows only an adsorption process.

Bis(4-amino-3-penten-2-onato) nickel(II), (Ni(APO) 2 ), and its NH deuterated analog, Ni(DAPO) 2 , were synthesized and their molecular structure and vibrational assignments were investigated by means of density functional theory (DFT) calculations. The molecular stability was investigated by applying the NBO and geometry calculations. The harmonic vibrational frequencies of Ni(APO) 2 and Ni(DAPO) 2 were obtained at the B3LYP level using 6-311G ∗ basis set. The calculated geometrical parameters and vibrational frequencies were compared with the experimental results. The measured vibrational band frequencies were interpreted in terms of the calculated vibrational normal modes. The scaled theoretical frequencies and the structural parameters were found to be in good agreement with the experimental data.

Bis(4-aminopent-3-en-2-onato) copper(II), Cu(APO) 2 , was synthesized and its total X-ray crystallographic data were determined. The molecular structure and vibrational spectra of this compound were investigated by means of density functional theory (DFT) calculations at the B3LYP level using 6-31G ** , 6-311G * , and 6-31++G * basis sets, and the results were compared with the experimental data. For comparison, the geometrical parameters and vibrational wavenumbers of Cu(APO) 2 were also calculated at the HF and MPW1PW91 levels using mixed basis sets (GEN), 6-311+G * for the Cu atom and 6-31G ** for all the other atoms. All of the measured IR and Raman bands were interpreted in terms of the calculated vibrational modes. The scaled theoretical frequencies and the structural parameters were in good agreement with the experimental data.

For the first time, nanoparticles of zinc chromite, spinel ZnCr(2)O(4) have been fabricated by the thermal decomposition of Zn-Cr gel prepared by sol-gel method in the presence of oxalic acid as a chelating agent. It was shown that the well-crystallized spinel structure is formed after calcination at 450°C. The nanospinel has been characterized by differential thermal analysis (DTA), X-ray powder diffraction (XRD), infrared spectroscopy (IR), and transmission electron microscope (TEM). The average particle size is approximately 13 nm according to the TEM image. The nanoparticles of zinc chromites showed excellent adsorption properties towards reactive dye, reactive blue 5 (RB5). The adsorption studies have been carried out for contact time, different pH values, different temperatures, and adsorbent doses. The investigation of removal kinetics of RB5 indicates that the removal process obeys the rate of second-order kinetic equation. The results indicate that the Langmuir adsorption isotherm fitted the data better than the Freundlich. Also, the photocatalytic degradation of RB5 using spinel ZnCr(2)O(4) under UV irradiation at pH=1 has been also examined. The results showed that the degradation of RB5 dye follows merely an adsorption process.

New oxo-bridge, mixed metal complex, [Fe2NiO(CH3CH2COO)6(H2O)3]·0.5H2O has been synthesized from the direct reaction between metal nitrate and propanoic acid and characterized by elemental analysis, infrared and electronic spectroscopy and single-crystal X-ray crystallography. This complex have a typical μ3-oxo trinuclear structure: (a) three metal atoms are situated in the apexes of the equilateral triangle; (b) μ3-oxygen atom and six propanoate ligands fulfill the bridge functions; (c) the monodentate water ligands complete the octahedral geometry of the metal ions. It crystallized in the triclinic, space group type P 1 ¯ . Two strong bands were observed in IR spectra at ∼1590 and ∼1420 (cm−1) stretching vibrations, the coordination mode of the carboxylate ligand can be assigned on the basis of the difference (Δν ⩽ 200 cm−1) of these two frequencies.

A new mixed ligand palladium(II) complex with bidentate NS-donor chelate, [PdCl(PPh3)L] (L: S-allyl β-N-(benzylidene)dithiocarbazate), has been prepared and characterized using single crystal X-ray diffraction and spectroscopic (electronic, IR, 1H NMR and 13C NMR) techniques. The shorter PdP bond distance, 2.255(7) A, than the sum of the single bond radii for palladium and phosphorus (2.41 A), showed partial double bond character. Visualizing and exploring the crystal structure using Hirshfeld surface analysis showed the presence of π··· π, N··· π, CH··· π, Cl···H and weak CH···S interactions as most important intermolecular interactions in the crystal lattice, which are responsible to extension of the supramolecular network of the compound and stabilization of the crystal structure.

Three new oxo-centered trinuclear complexes, one of them a mixed-valence complex [Mn3O(C7H4O2Cl)6(Py)3]Py (1) and the others, mixed-metal complexes of [Fe2MnO(C7H4O2Cl)6(Py)3]NO3 (2) and [Fe2CoO(C7H4O2Cl)6(Py)3] (3) were synthesized by the direct reaction between metal nitrates and p-chlorobenzoic acid. These complexes were characterized by elemental analyses (CHN), atomic absorption spectroscopy and spectral (IR, electronic) studies. These are new type of oxo-bridged mixed-metal complexes in which the carboxylate ligand is pchlorobenzoic acid. The UV spectra of the complexes exhibited a strong band in the region 42,500 cm-1 which is related to the (? ? ?*) transitions of the pyridine ligand. The IR spectra of these compounds showed two strong stretching vibrations bands, indicating a bridging coordination mode of the carboxylic group of the ligand in the complexes.

Two novel oxo-centered trinuclear compounds, [M2M′O(C3H3O2)6(H¬2O) 3]+ (M = Cr, M′ = Cr, Fe) have been synthesized. The complexes were characterized by elemental analysis, infrared and electronic spectroscopy and thermogravimetric analysis (TGA). These complexes contain unsaturated carboxylate bridging ligands that cause them to have potential scopes for polymerization in the solid state by cross-linking of substituents. Bridging coordination modes for carboxylates were indicated by presence of asym (M2M'O) vibrations in the infrared spectra.

A new bidentate Schiff base (HL) derived from the condensation of S-allyldithiocarbazate with pyrrole-2-carboxaldehyde and its complex NiL2 have been prepared and characterized by elemental analyses, IR, NMR, UV-Vis spectroscopy, mass spectrometry, and molar conductivity measurements. The structures of ligand and NiL2 complex have been determined using X-ray diffraction analysis. Ligand and Ni(II) complex crystallize in the tetragonal space group P42 /n with the unit cell parameters a = 22.1827(18) A, c = 4.5388(3) A, V = 2233.4(3) A3, Z = 8 and in the monoclinic space group P21 /c with the unit cell parameters a = 9.9998(14) A, b = 15.1322(16) A, c = 7.5920(11) A, β = 99.397(17)°, V = 1133.4(3) A3, and Z = 2, respectively. X-ray crystallographic structural analysis confirms that two Schiff bases of S-allyldithiocarbazate is coordinated to nickel as a uninegatively charged bidentate NS chelating agent via the azomethine nitrogen and the thiolate sulfur. NiL2 is square planar with cis-configuration.

S-allyl-β-N-[(2-hydroxyphenyl)methylene]hyrazinecarbodithioate) (1, H2L), the Schiff base of dithiocarbazate with unsaturated allyl substitution, can act as a new tridentate SNO ligand H2–L and react with cobalt(II) nitrate hexahydrate to form the novel linear trinuclear isovalence Co(II) complex, [Co3(H–L)2(L)2] 2C2H5OH (2). The compounds were characterized by elemental analysis, infrared, and ultraviolet spectroscopy. Compound 2 was also characterized by single-crystal X-ray analysis and crystallizes in the orthorhombic space group, Pbcn, with a = 30.643(1) A, b = 9.118(4) A, c = 19.017(7) A, α = β = γ = 90°, V = 5312.95 A3, Z = 4, and R 1 = 0.0790, (wR 2) = 0.1223. The six-coordinate central Co(II) atom is bonded to two deprotonated metal-containing ligands. The terminal Co(II) atoms are in a square planar SNON four-coordinate environment and connected to the central Co(II) by N-atoms from the ligand backbone. For quantifying the intermolecular interactions in crystal lattice, the new d norm surface and the breakdown of fingerprint plots have been used for visualizing and exploring the compound 2.

S-allyl-β-N-(benzylidene)dithiocarbazate (sabdtc, 1), prepared from hydrazine hydrate, carbon disulfide, allyl bromide and benzaldehyde, reacts with copper(II) nitrate in ethanol solution to form the complex Cu(sabdtc)2 (2). 1 function as a single negatively charged bidentate chelating ligand and coordinates via the azomethine nitrogen atom and thioenolate sulfur atom to the metal ion. 1 and 2 were characterized by elemental analyses, 1H NMR, 13C NMR, UV/Vis, IR, and mass spectra. Spectroscopic evidences suggest a four-coordinate distorted square planar structure for 2. The molecular and crystal structure of 2 was determined by single crystal X-ray analysis. Crystallographic data for 2 at 291(2) K: space group C2/c, a = 20.340(3), b = 15.503(3), c = 7.659(1) A, β = 95.96(2)°, Z = 4, R1 = 0.044 and wR2 = 0.0689.

Three new oxo-centered trinuclear mixed-bridged carboxylate complexes with terminal unsaturated ligands ([M2M′(μ3-O)(μ-O2C3H3)5(μ-O4C6H7)(O2C3H3) (H2O)2]·2H2O [M = Fe, M′ = Fe (1); M = Fe, M′ = Cr (2); M = Cr, M′ = Fe (3)]) have been synthesized and characterized by means of elemental analyses, IR spectra and crystal structure analyses. The compounds crystallize isotypically in the orthorhombic space group type Pbcn with a = 24.622(3) A, b = 16.304(2) A, c = 17.491(2) A, V = 7021.5(15) A3 (1), a = 24.708(5) A, b = 16.290(2) A, c = 17.394(2) A, V = 7001.0(18) A3 (2), a = 24.611(4) A, b = 16.300(3) A, c = 17.359(3) A, V = 6964(2) A3 (3), and Z = 8. The infrared spectra show resolved bands arising from νasym(OCO) and νsym(OCO) vibrations of monodentate and bridging carboxylate ligands along with those of νasym(M2M′O) vibrations in the complexes.

The reaction of 4-amino-1,2,4-Δ 2 -triazoline-5-thione (ATT, 1) with AgNO3 in methanol led to the complex (Ag(ATT)2)NO3 (2). 2 was characterized by elemental analyses, 1 H NMR, IR, and Raman spectroscopy as well as single-crystal X- ray diffraction. The molecular structure of 1 was also determined by single crystal X-ray analysis. Crystal data for 1 at -80 C: space

The transamination reaction of Sm{N(SiMe3)2}2(THF)2 with two dipyrrole ligands of formula RR‘C(α-C4H3NH)2 (R = R‘ = Et; R = Me, R‘ = Ph) has been examined. The reactions in THF and under N2 gave two similar tetranuclear dinitrogen complexes, {[Et2C(α-C4H3N)2Sm}4(THF)2](μ-N2)·2THF and [{[(C6H5)(CH3)C(α-C4H3N)2]Sm}4(DME)2](μ-N2), where the dinitrogen unit has undergone a four-electron reduction via cooperative attack of four divalent samarium atoms and remained coordinated both side-on and end-on between the four coplanar metal centers. The same reaction carried out with diethyldipyrrolylmethane under an argon atmosphere afforded the divalent samarium macrocyclic cluster {[Et2C(α-C4H3N)2]Sm}8(THF)4·4THF. In the case of the reaction with the methylphenyldipyrrolylmethane ligand under N2, the unprecedented hexanuclear mixed-valence SmII/SmIII cluster [([(C6H5)(CH3)C(α-C4H3N)2][(C6H5)(CH3)C(α-C4H3N)(β-C4H3N)]{[(C6H5)(CH3)C]2(α-C4H3N)2(α,α‘-C4H2N)}Sm3)(THF)3]2, containing tripyrrolide, “N-confused”, and regular...

The reaction of 4-amino-1, 2, 4-triazin-3(2H)-thione-5-one (ATTO, 1) with [Cu(PPh3)2]NO3 in ethanol led to the complex [Cu(PPh3)2(ATTO)]NO3 (2). 2 was characterized by elemental analyses, IR, 1H NMR and Raman spectroscopy. A single-crystal X-ray diffraction of compound 2 revealed that ATTO acts as a bidentate ligand via its nitrogen and sulfur atoms. Crystal data for 2 at 20 °C: space group P21/n with a = 975.7(1), b = 1533.5(2), c = 2504.2(3) pm, β = 92.25(1)°, Z = 4, R1 = 0.0632.

In the title compound, C10H16N+·C12H15F3N2O3P−, the two P—N distances are significantly different [1.740 (2) and 1.641 (2) Å]. In the crystal structure, cations and anions are connected via intermolecular N—H...O hydrogen bonds to form chains of centrosymmetric rings propagating in the b-axis direction.

The reaction of 4-amino-5-methyl-1,2,4-triazol-3(2H)-thione (HAMTT, 1 ) with cadmium(II) acetate in ethanol leads to[Cd(η 2 -AMTT) 2 (H 2 O) 2 ]( 2 ); the reaction of 2 with nitric acid inethanol produces the single-crystals of [Cd(η 2 -HAMTT) 2 -(H 2 O) 2 ](NO 3 ) 2 ( 3 ). 2 and 3 have been characterized by IR, Raman, 1 H NMR spectroscopy and elemental analyses; furthermore, 3 has Synthese und Kristallstruktur von Diaqua-bis(4-amino-3-methyl-1,2,4-triazol-5-thion)cadmium(II)-nitrat Inhaltsubersicht. Die Reaktion von 4-Amino-5-methyl-1,2,4-tria-zol-3(2H)-thion) (HAMTT, 1 ) mit Cadmiumacetat in Ethanol er-gibt [Cd(η 2 -AMTT) 2 (H 2 O) 2 ]( 2 ); die Reaktion von 2 mit Salpeter-saure in Ethanol ergibt Einkristalle von [Cd(η 2 -HAMTT) 2 -(H 2 O) 2 ](NO 3 ) 2 ( 3 ). 2 und 3 wurden mittels IR-, Raman- und 1 H-NMR-Spektroskopie sowie durch Elementaranalysen charakte- 1 Introduction The chemistry of N N C S linkage has been extensivelystudied and reviewed [1 3]. One class of such compoundsis the 4-amino-5-thio substituted 1,2,4-triazoles. Metal che-lates of these derivatives containing sulfur and nitrogencould be of interest from the viewpoint of chemical reactiv-ity and biological activity [4]. These compounds have beenreported to possess significant antifungal, antibacterial andinsecticidal properties [5 7]. Some of new triazole deriva-tives have been synthesized as potential antidepressants [8]and plant growth regulators [9]. Furthermore, metal com-plexes containing triazole ligands may also show biologicalactivity [10]. 4-amino-5-thio substituted 1,2,4-triazoles existin the two tautomeric forms as shown in Figure 1.