- RATE OF LIGAND EXCHANGE OF TRIS(ACETYLACETONATO)IRON(III) WITH TRIFLUOROACETYLACETONE AND TRIS(TRIFLUOROACETYLACETONATO)IRON(III) WITH ACETYLACETONE
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The rate of ligand exchange of tris(acetylacetonato)iron(III) with trifluoroacetylacetone and tris(trifluoroacetylacetonato)iron(III) with acetylacetone in carbon tetrachloride has been measured spectrophotometrically and the reaction mechanism was discus
- Sekine, Tatsuya,Inaba, Kazuho
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- ELECTRON PARAMAGNETIC RESONANCE OF FERRIC ACETYL ACETONATE.
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X and Q band EPR spectra for Fe(acac)//3 in the temperature range from 100 to 443 K indicate coexistence of two types of Fe(III) high spin complexes. A temperature dependence study of EPR spectra exhibits a phase transition temperature at 353 K.
- Hedewy,Hoffmann
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- The direct electrochemical synthesis of transition metal acetylacetonates
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Acetylacetonates were prepared electrochemically in good yield using the pure liquid ligand, acetylacetone, as the solvent, in which the supporting electrolyte, tetra-n-butyammonium hexafluorophosphate, was dissolved; the metal of interest served as the electrodes. The products were characterized by UV-visible spectrometry (color) and mass spectrometry. Both a lower, M(AcAc)2, and a higher, M(AcAc)3, oxidate state were formed for the cobalt and manganese systems; the identity of the product(s) could be biased by a careful choice of the potential used for the synthesis.
- Long,Lagowski
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- A Novel [Fe(acac)3] Interspersed g-C3N4 Heterostructure for Environmentally Benign Visible-Light-Driven Oxidation of Alcohols
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The present work describes facile synthesis of a novel Fe(acac)3 decorated g-C3N4 heterostructure. Mixing of iron(III) complex with g-C3N4 thorough simple ultrasonication leads to the formation of the heterostructure. The material was thoroughly characterized by FT-IR, powder XRD, SEM, TEM, UV/Vis DRS and XPS analysis. The analytical results clearly indicate that the FeIII complex is uniformly interspersed with g-C3N4. The results also suggest that there exists synergy between two components in the heterostructure for enhance catalytic performance. This novel material was used as heterogeneous catalyst for visible light driven oxidation of a number of alcohols by H2O2. The best ratio of the Fe(acac)3 and g-C3N4 is determined with PL analysis. Cold LED light was used as source of visible light. Metal complex decorated g-C3N4 heterostructured materials have been rarely used as catalysts for synthetically useful organic transformations. Thus present work on the use of this materials promises to open up new avenues in future growth in metal complex-graphitic nitride based heterostructure nanocatalysis.
- Devi, Meghali,Ganguly, Sreejeeb,Bhuyan, Bishal,Dhar, Siddhartha Sankar,Vadivel, Sethumathavan
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- Achirality in the low temperature structure and lattice modes of tris(acetylacetonate)iron(III)
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Tris(acetylacteonate) iron(iii) is a relatively ubiquitous mononuclear inorganic coordination complex. The bidentate nature of the three acetylacteonate ligands coordinating around a single centre inevitably leads to structural isomeric forms, however whether or not this relates to chirality in the solid state has been questioned in the literature. Variable temperature neutron diffraction data down to T = 3 K, highlights the dynamic nature of the ligand environment, including the motions of the hydrogen atoms. The Fourier transform of the molecular dynamics simulation based on the experimentally determined structure was shown to closely reproduce the low temperature vibrational density of states obtained using inelastic neutron scattering.
- Ellis, Thomas K.,Kearley, Gordon J.,Piltz, Ross O.,Jayasooriya, Upali A.,Stride, John A.
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- Investigation of nanocrystalline phases in Li-La-Fe-O system formed by the decomposition of acetylacetonato complexes
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Applying a new synthesis route based on the thermal decomposition of a mixture acetylacetonato complexes, Li(AA), La(AA)3 and Fe(AA)3, Li, La ferrite (Li0.5La0.08Fe2.42O4) was formed. The element analysis performed by ICP technique and the Rietveld refinement data indicate that the sample is composed of three phases: Li0.5La0.08Fe2.42O4 (69%, SG P4332, a = 8.3445(3) ?), La0.14Fe3O4 (16%, SG F d over(3, ?) m, a = 8.403(1) ?) and LiFeO2 (15%, SG F m over(3, ?) m, a = 4.2291(8) ?). A partial substitution Fe3+ → La3+ in Li ferrite and La insertion at 16c site in Fe3O4 occur at low concentrations. A partial cation ordering at 4b and 12d octahedral sites in Li0.5La0.08Fe2.42O4 was noticed. TEM micrograph shows that the nanoparticles are spherically shaped and that the particle distribution is in the range between 7 and 33 nm. The sample exhibits superparamagnetic behavior, thus the composite has potential industrial applications.
- Vu?ini?-Vasi?,Antic,Kremenovi?,Nikolic,Blanusa,Raki?,Spasojevic,Kapor
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- Isomerism, molecular structure, and vibrational assignment of tris(triflouroacetylacetonato)iron(III): An experimental and theoretical study
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The isomerism, optimized molecular structure, UV spectrum, metal-ligand bond strength, and vibrational assignment of tris(triflouroacetylacetonato)iron(III), Fe(TFAA)3, were investigated by the aid of theoretical calculations (using DFT and Atoms-in-Molecules (AIM) at the B3LYP/6-311++G(d,p) level) and experimental methods (vibrational and UV spectroscopy). To explore the effect of the CF3 substituent in the β-position on the properties of complex, the above theoretical and experimental results of the titled complex compared with the corresponding data for tris(acetylacetonato) iron(III), Fe(AA)3. Both theoretical and experimental results confirmed that there is no significant difference in the strength of the Fe?O bond in these complexes. The effect of the CF3 group on the experimental vibrational bands of the chelated ring agrees with the calculated results. Comparing the observed and calculated vibrational spectra suggests that vibrational spectroscopy cannot be used to determine the type of isomer in the sample. However, due to the small difference of energy between the fac and mer isomers in the Fe(TFAA)3, the presence of both isomers in the sample is possible. The computed quantum chemical descriptors of Fe(TFAA)3 and Fe(AA)3 were also compared.
- Gandomi, Farzad,Takjoo, Reza,Tayyari, Sayyed Faramarz,Vakili, Mohammad
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- Effect of technique of applying layers of metal acetylacetonates on acid-base and chromatographic properties of sorbents
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A series of chromatographic sorbents, which differ by way of applying modifying chelates of acetylacetone was obtained. The acid-base and chromatographic properties of sorbents with thermally and chemically grafted layers of metal acetylacetonates were investigated. It was shown that the modifi cation of the mineral sorbents with metal acetylacetonates leads to a change in the surface acidity, as well as to an increase in the polarity and selectivity with respect to different classes of compounds.
- Slizhov, Yu. G.,Matveeva,Minakova
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- Preparation and characterisation of crystalline tris(acetylacetonato)Fe(III) films grown on p-Si substrate for dielectric applications
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Thin tris(acetylacetonato)iron(III) films were prepared by sublimation in vacuum on glass and p-Si substrates. Then comprehensive studies of X-ray fluorescence (XRF), X-ray diffraction (XRD), optical absorption spectroscopy, AC-conductivity, and dielectric permittivity as a function of frequency and temperature have been performed. The prepared films show a polycrystalline of orthorhombic structure. The optical absorption spectrum of the film was identical with that of the bulk powder layer. For electrical measurements of the complex as insulator, sample in form of metal-insulator-semiconductor (MIS) structure was prepared and characterised by the measurement of the capacitance and AC-conductance as a function of gate voltage. From those measurements, the state density Dit at insulator/semiconductor interface and the density of the fixed charges in the complex film were determined. It was found that Dit was of order 1010 eV-1/cm2 and the surface charge density in the insulator film was of order 1010 cm-2. The frequency dependence of the electrical conductivity and dielectric properties of MIS structures were studied at room temperature. It was observed that the experimental data follow the correlated barrier-hopping (CBH) model, from which the fundamental absorption edge, the cut off hopping distance, and other parameters of the model were determined. It was found that the capacitance of the complex increases as temperature increases. Generally, the present study shows that the tris(acetylacetonato)iron(III) films grown on p-Si is a promising candidate for low-k dielectric applications, it displays low-k value around 2.0.
- Dakhel,Ali-Mohamed
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- Immobilisation of iron tris(β-diketonates) on a two-dimensional flat amine functionalised silicon wafer: A catalytic study of the formation of urethane, from ethanol and a diisocyanate derivative
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A series of immobilised iron tris(β-diketonato) catalysts on a Si-wafer was prepared, by covalently anchoring the Fe(β-diketonato) 3 complexes [where β-diketonato = (RCOCHCOR′)-, with 1 = acac (R = CH3; R′ = CH3), 2 = dbm (R = C6H5; R′ = C6H5), 3 = tfaa (R = CH3; R′ = CF3), and 4 = hfaa (R = CF3; R′ = CF3)], onto an aminated functionalised Si-wafer. These new catalysts were characterised by X-ray photo-electron spectroscopy (XPS) and atomic force microscopy (AFM). XPS data revealed that ca. 27-91% of all the amine groups anchored the catalyst, Fe(β-diketonato)3. Different Gaussian peaks could be fitted into the F 1s peak, due to the fluorine either being positioned adjacent to the -C-O-Fe-, or to the -C-N-Fe-. The binding energy of the Fe 2p3/2 peak varied between ca. 710.4 and 711.0 eV, depending on the electron donating properties of the R-groups on the β-diketonato ligands, expressed as the sum of the Gordy group electronegativities of the R-groups in the β-diketonato ligands. The AFM photographs showed that the surface changed dramatically after each treatment: after amination (binding of the aminate silane onto the hydroxylate Si-wafer) the Si-wafer turned from flat with a few spikes, to a very wavy surface with smooth lumps. The surface topography again changed, after covalent anchoring of the iron tris(β-diketonato) complexes, to a nodular surface with poorly defined grain boundaries. These immobilised iron tris(β-diketonato) on Si-wafer catalysts, were evaluated for their catalytic activity, during the formation of hexamethylenediurethane from hexamethylenediisocyanate and ethanol. The TOF varied between 15 and 46 s-1, depending on the electron donating properties of the R-groups on the β-diketonato ligands. The more electron donating the R groups, the higher the TOF.
- Conradie,Conradie,Erasmus
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- Novel Synthesis of Tris(acetylacetonato)iron(III)
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The reaction of iron(III) hydroxide with acetylacetone, in the absence of any buffer, readily gives highly crystalline tris(acetylacetonato)iron(III), , in very high yield.Its mass spectrum provides evidence for rearrangement to give Fe-CH3 spe
- Chaudhuri, Mihir K.,Ghosh, Soumitra K.
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- Kinetics and Mechanism of Ligand Exchange of Tris(acetylacetonato)-iron(III) in Acetylacetone
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Tris(acetylacetonato)iron(III) undergoes ligand exchange in acetylacetone at 4-16 deg C without side reactions.The exchange rate is expressed by Rate = (ka + kb)( ca. 0.01 M, ca. 0.05 M), and the rate constant (10.2 deg C) and activation parameters are ka = (8.9 +/- 1.2) * 10-4 s-1, ΔH = 14.4 +/- 0.9 kcal mol-1, ΔS = -22 +/- 3 cal K-1 mol-1 and kb = (2.22 +/- 0.20) * 10-2 M-1 s-1, ΔH = 16.9 +/- 0.4 kcal mol-1, ΔS = -6.1 +/- 1.3 cal K-1 mol-1 (1 cal = 4.18 J, 1 M = 1 mol dm-3).No deuterium isotope effect on the rate.The rate-determining steps seem to correspond to the formation of intermediates containing a one-ended acac- and an Hacac molecule (the ka path), and the anion and a water molecule (the kb path), by the SN2 mechanism.
- Kido, Hiroaki,Saito, Kazuo
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- The pentacyanonitrosylferrate(2-) ion. IV. Reactions with the carbanions of pentane-2,4-dione and 3-methylpentane-2,4-dione
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The products from the reaction of pentane-2,4-dione (acac H) with the anion 2- in the presence of alkali are , 4-, NO, and the oxime HON=C(COCH3)2.A reaction mechanism is prposed involving formation of an adduct of 2- and the carbanion, metal-to-ligand charge transfer, loss of NO ligand rearrangement.A similar reaction occurs with 3-methylpentane-2,4-dione.
- Butler, Anthony R.,Calsy, Adrianne M.,Glidewell, Christopher
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- Optimized molecular geometry, vibrational analysis, and Fe-O bond strength of Tris(α-cyanoacetylacetonate)iron(III):An experimental and theoretical study
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Tris(α-cyanoacetylacetonate)iron(III), Fe(CNacac)3, was synthesized and its molecular geometry, Raman, IR, and UV spectra were recorded and analyzed with the mentioned calculated spectra by using the B3LYP/6-311++G(d,p) level and comparing with tris(acetylacetonate)iron(III), Fe(acac)3, as parent molecule. A full assignment along to major contributes for of UV and vibrational experimental bands with their potential energy distribution (PED) of Fe(CNacac)3, has been done. The calculated and experimental results, including molecular geometry, Atoms in Molecules (AIM), Natural bond orbital (NBO) analysis, vibration and UV-Vis spectra were shown the cyano substitution in α position, increases the resonance of chelating ring and increases the Fe?O bond strength of the mentioned molecule in comparison to that Fe(acac)3.
- Darugar, Vahidreza,Gandomi, Farzad,Takjoo, Reza,Tayyari, Sayyed Faramarz,Vakili, Mohammad
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- Reactivity and Moessbauer spectroscopic characterization of an Fe(IV) ketimide complex and reinvestigation of an Fe(IV) norbornyl complex
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Thermolysis of Fe(Ni=CtBu2)4 (1) for 8 h at 50 °C generates the mixed valent Fe(III)/Fe(II) bimetallic complex Fe2(Ni=CtBu2)5 (2) in moderate yield. Also formed in this reaction
- Lewis, Richard A.,Smiles, Danil E.,Darmon, Jonathan M.,Stieber, S. Chantal E.,Wu, Guang,Hayton, Trevor W.
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p. 8218 - 8227
(2013/08/23)
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- Process for making metal acetylacetonates
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The present invention provides an improved, economical and environmentally benign process for metal complexes of acetylacetone having the general formula, M(acac)n wherein M is a metal cation selected from the group consisting of Fe, Co, Ni, Cu, Zn, Al, Ca, Mg, Mo, Ru, Re, U, Th, Ce, Na, K, Rb, Cs, V, Cr, and Mn etc., n is an integer which corresponds to the electrovalence of M, are obtained by reacting the corresponding metal hydroxide, metal hydrated oxide or metal oxide with a stoichiometric amount of acetylacetone and separating the product.
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Page/Page column 5
(2010/02/07)
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- Kinetics and mechanism of ligand substitution in β-diketone complexes of iron(III). Solvolysis controlling the substitution process in alcohol media
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Conventional and stopped-flow spectrophotometry was used to study the kinetics of ligand substitution in a number of tris β-diketone iron(III) complexes, Fe(O∩O)3, by 8-hydroxyquinoline (=HO∩N) in alcohol media (O∩O-=anion of the β-diketones pentane-2,4-dione, 2,6-dimethylheptane-3,5-dione, 2,2,6,6-tetramethylheptane-3,5-dione, 1-phenylbutane-1,3-dione, 1,3-diphenylpropane-2,3-dione, and 1-(2-thienyl)-4,4,4-trifluorobutane-1,3-dione). As shown by spectrophotometry, the solutions of complexes Fe(O∩O)3 in alcohols ROH are subject to solvolytic dissociation, leading to solvento species Fe(O∩O)2S2 and to binuclear complexes [Fe(O∩O)2(RO)]2 (S=ROH and RO-, respectively). The reaction of complexes Fe(O∩O)3 with HO∩N in alcohol media, leading to Fe(O∩N)3, is triphasic. The corresponding first-order rate constants k1, k2, and k3 are independent of the concentration of the entering ligand HO∩N and follow the order k1>k2>k3, with k1/k2≈10 and k1/k3≈102. For a given system Fe(O∩O)3/HO∩N/ROH, the size of k1, k2, and k3 correlates with the solvent polarity parameter ET(30). Rate constant k1 describes the solvolytic dissociation of the complexes Fe(O∩O)3 and rate constant k3 the solvent-initiated splitting of the binuclear complexes [Fe(O∩O)2(RO)]2. Rate constant k2 is assigned to the solvolytic dissociation of the intermediate complex Fe(O∩O)2(O∩N). Depending on the nature of the coordinated β-diketone and solvent ROH, k1 ranges from 0.04 to 2 s-1, k2 from 0.007 to 0.2 s-1, and k3 from 0.002 to 0.01 s-1 at 298 K. The mechanism of the ligand substitution processes is discussed.
- Gumbel, Gerhard,Elias, Horst
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- Solid-Phase Synthesis of Iron(III) Acetylacetonate upon Mechanical Activation
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The solid-phase interaction of iron(III) chloride and sodium acetylacetonate with formation of iron(III) acetylacetonate and sodium chloride in the course of mechanical treatment in a vibratory ball mill was studied. This interaction proceeded with the intermediate formation of an activated mixture, which, being heated or mechanically activated for a longer time, gave the reaction products. The effects of the mechanical treatment conditions on the process, on the yield of iron(III) acetylacetonate, and some properties of the activated mixtures were studied. The yield of iron(III) acetylacetonate reaches ～80% under optimal conditions. After a preliminary mechanical activation of a reaction mixture, the synthesis of iron(III) acetylacetonate can be carried out in the self-propagating mode.
- Petrova,Borisov,Aleshin,Makhaev
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p. 328 - 331
(2008/10/08)
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- Synthesis. Characterization and Biological Activity of some 3d Metal Complexes of N-Isonicotinoyl-N'-2- Furanthiocarbohydrazide
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A new ligand, N-isonicotinoyl-N'-2-furanthiocarbohydrazide (H2INfth) has been prepared by the reaction of isonicotinic acid hydrazide and carboxymethyl-2-furandithioate. The complexes [VO(HINfth)2], [Mn(HINfth)2], [Fe(HINfth)2], [Fe(INfth)(acac)], M[INfth)(H2O)2] [M=Co(II),Ni(II)], [M(INfth)] and [M(H2INfth)Cl2] [M=Cu(II),Zn(II)] have been prepared and characterized by elemental analyses, magnetic susceptibility, electronic, NMR, IR, mass and FAB mass spectral data. The room temperature ESR spectraof oxovanadium(IV) and iron(III) complexes yield values characteristic of square-pyramidal and octahedral complexes, respectively. The Moessbauer spectra of [Fe(HINfth)2] and [Fe(INfth)(acac) at room temperatureand 78 K suggest the presence of highspin iron(II) and the intermediatespin state of iron(III) with an (4)A2 ground state. The ligand and the complexes have been screened for activity against a number of bacteria and fungi.
- Singh, Nand K.,Kushawaha, Surendra K.,Dixit, Ajai Kumar
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p. 1236 - 1264
(2008/10/08)
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- Preparation and properties of heterobimetallic alkoxides of iron(III) with aluminium(III), niobium and tantalum
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Reactions of anhydrous FeCl3 with Ki)4> and Ki)6> (M = Nb, Ta) in 1:3 molar ratios in isopropyl alcohol-benzene mixture result in products having the compositions. i)4>3>(1a) and i)6>3> (2a and 3a) respectively.Reactions of these products with alcohols of varying steric bulk yield mixed alkoxy-isopropoxy bimetallic complexes.All these bimetallic alkoxide derivatives have been characterized by elemental/group analysis and molecular weight determinations as well as by infrared, visible spectral and magnetic studies.
- Shah, A,Singh, J,Singh, A,Mehrotra, R C
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p. 1018 - 1023
(2007/10/02)
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