三草酸合铁(Ⅲ)酸钾合成方法的改进

三草酸合铁(III)酸钾具有工业生产价值,其合成作为化学专业本科生的经典实验项目,按教材实验的效果却不尽人意。本文在严谨的化学平衡理论分析基础上,首次提出提高合成产率的关键是严格控制草酸和草酸钾的用量,改进后的合成条件为：氧化步骤H2O2的浓度为6%,水浴温度为40°C;充分氧化后,微沸2分钟;酸溶步骤中草酸稍微过量,草酸钾过量10%;结晶时做到充分冷却。经此改进,可简化操作,节约原料,实验室平均产率达87%,教学中学生实验平均产率超过70%。     

Synthesis and the thermal decomposition of iron(III) tris(oxalato) ferrate(III) tetrahydrate

The paper describes the synthesis and thermal decomposition of Fe[Fe(C₂O₄)₃]4H₂O in air. The compound is completely dehydrated at 170°C and some reduction in the inner sphere iron(III) occurs. At 290°C, a mixture of ferric oxide and ferrous oxalate is obtained. Beyond 420°C, the decomposition is complete and final residue is ferric oxide. A probable reaction mechanism is proposed.     

Synthesis and Crystal Structure of Tris(N-p- methylphenyl-3-hydroxy- 2-ethyl-4-pyridinonato)iron(III)

1 INTRODUCTION A number of hydroxypyrones and hydroxypyridinones are being assessed or considered as orally effective chelators for treatment iron or aluminum overload[1,2]. Almost all present and potential applications involve the tris-ligand complexes of metal(III) cations, as for example in administration of iron(III) complexes for the treatment of anaemia[3], and the appropriate isotopes (e.g. 67Ga, 111In, 90Y) for radiotherapy or the isotopes of gadolinium for magnetic resonance …     

Tris(2,2,2-trichloroethoxy)iron(III) complexes

Summary The preparation, magnetic moments, i.r., reflectance and⁵⁷Fe Mössbauer spectra of adducts of tris(2,2,2-trichloroethoxy)iron (III) complexes are reported. An alkoxybridged structure is supported by i.r. spectra.⁵⁷Fe Mössbauer spectra are explained in terms of two inequivalent sites in highspin iron(III) octahedral symmetry.Abbreviations Pic-O -picolineN-oxide - Ur urea - DMU N,N-dimethylurea - Suc succinimide - Diox dioxan - Bipy 2,2-bipyridine - Phen 1,10-phenanthroline     

Synthesis and Crystal Structure of Tris(N-p- methylphenyl-3-hydroxy- 2-ethyl-4-pyridinonato)iron(III)①

The complex [Fe(C14H14NO2)3](2H2O has been prepared by reaction of N-p-methylphenyl-3-hydroxy-2-ethyl-4-pyridinone with FeCl3(6H2O. A single-crystal X-ray study shows that the iron atoms lie in a trigonally distorted octahedral environment coordinated to the hydroxy and ketone oxygen atoms of three ligands in the mer configuration Mr=773.57(C42H46N3O8Fe). The crystal is hexagonal with space group P1c; a=15.943(2), c=17.612(4)?, V=3877.0(12)?3, Z=4, Dc=1.325g/cm3, (=0.445mm－1, F(000)=1634, R=0.0446, wR= 0.1154 for 3085 reflections with I >2((I). The bond lengths from iron to oxygens are 1.980(1)? for the ketone oxygens and 2.071(1)? for the hydroxy oxygens. The molecule exhibits the expected propeller shape, and the angle of the trigonal twist is 48.37(. The dihedral angles are 0.5(2)° between chelate ring plane and pyridine ring plane and 71.31(7)° between pyridine ring plane and benzene ring plane. The solvent H2O(O(3) and O(4)) molecules are linked with O(2) and O(1) by hydrogen bonds with bond lengths 2.900(1) and 2.999(1), respectively.     

Tris(oxalato)phosphorus acid and its lithium salt

The conversion of three equivalents of anhydrous oxalic acid with phosphorus pentachloride yields tris(oxalato)phosphorus acid 1, which crystallizes from diethyl ether solutions as protonated diethyl ether complex [(Et2O)2H](+)[P(C2O3)3)]-. The superacidic compound can be used as catalyst for Friedel-Crafts-type reactions. Upon neutralization with lithium hydride, the lithium salt Li[P(C2O3)3] 2 is obtained, which is highly soluble in aprotic solvents and which exhibits a wide voltage window. Thus, the lithium compound is a promising candidate as electrolyte for high performance non-aqueous batteries.     

Tris(1-adamantanecarboxylato)bismuth(III): Synthesis and structure

Tris(1-adamantanecarboxylato)bismuth(III) was synthesized by reacting triphenylbismuth with 1-adamantanecarboxylic acid in toluene. The bismuth atom in tetramer {Bi[OC(O)C₁₀H₁₅]₃}₄ is coordinated by 10 oxygen atoms of bidentate-chelating and two types of chelate-bridging adamantanecarboxylate ligands (Bi-O, 2.191–2.955 and 3.634 Å).     

Ligand field analysis of metal-oxygen interactions—I. Tris(oxalato)cobaltate(III)

Ligand field analysis of [Co(ox)₃]³⁻ has been performed using the angular overlap model (AOM) approach. The metal-oxygen interactions were treated as locally anisotropic. Experimental spectra were well reproduced by the calculations in which the Trees' correction was included. The effect of geometrical distortions on the calculated energies of ligand field states has been investigated.     

Binuclear Nickel(II) and Cobalt(III) Complexes with Dissimilar Bridges: Synthesis,Spectroscopy, Crystal Structure,and Magnetism

Two novel binuclear nickel(II) and cobalt(III) complexes with two or three dissimilar bridges, [Ni₂(tacn)₂(μ‐N₃)₂(μ‐O₂CPh)](ClO₄)?H₂O ( 1 ) and [Co₂(tacn)₂(μ‐N₃)(μ‐OH)(μ‐O₂CPh)](ClO₄)₃ ( 2 ) (tacn=1,4,7‐triazacyclononane), were synthesized and structurally as well as magnetically characterized. Both compounds have a discrete binuclear structure, bridged by two N₃^? ions and one carboxylato group of the benzoate ion for 1 and one N₃^? ion, one carboxylato group of the benzoate ion, and one hydroxy group for 2 ; the macrocyclic ligand tacn acts as terminal ligand. The magnetic data of compound 1 were analyzed by means of ? = ?2J?₁?₂?D(?₁²+?₂²), leading to J = 19.6 cm^?1, g=2.07, D = 4.01 cm^?1, and zJ′ = 0.32 cm^?1. The ferromagnetic interaction is discussed on the basis of the structural features.     

Photoelectron detachment and solvated electron dynamics of the cobalt(III) and iron(III) oxalato complexes

The photochemical redox reaction kinetics of [M(III)(C(2)O(4))(3)](3-) [M = Co, Fe] complexes have been reexamined and studied by time-resolved spectroscopy. The redox mechanisms of the two systems, Co and Fe, were found to be similar to each other, and solvated electrons were observed immediately after 266/267 nm photoexcitation. A reaction mechanism is proposed that involves photoelectron detachment as a primary process. The charge-transfer bands for both complexes, which had been attributed to ligand to metal charge-transfer (LMCT) transitions previously, are reassigned to charge transfer to solvent (CTTS) transitions.     

Carboxylate-Free Manganese(II) Phosphonate Assemblies: Synthesis, Structure, and Magnetism

The reaction of manganese(II) salts with organophosphonic acid [t-BuPO(3)H(2) or cyclopentyl phosphonic acid (C(5)H(9)PO(3)H(2))] in the presence of ancillary nitrogen ligands [1,10-phenanthroline (phen) or 2,6-bis(pyrazol-3-yl)pyridine (dpzpy)], afforded, depending on the stoichiometry of the reactants and the reaction conditions, dinuclear, trinuclear, and tetranuclear compounds, [Mn(2)(t-BuPO(3)H)(4)(phen)(2)]·2DMF (1), [Mn(3)(C(5)H(9)PO(3))(2)(phen)(6)](ClO(4))(2)·7CH(3)OH (2), [Mn(3)(t-BuPO(3))(2)(dpzpy)(3)](ClO(4))(2)·H(2)O (3), [Mn(4)(t-BuPO(3))(2)(t-BuPO(3)H)(2)(phen)(6)(H(2)O)(2)](ClO(4))(2) (4), and [Mn(4)(C(5)H(9)PO(3))(2)(phen)(8)(H(2)O)(2)](ClO(4))(4) (5). Magnetic studies on 1, 2, and 4 reveal that the phosphonate bridges mediate weak antiferromagnetic interactions between the Mn(II) ions have also been carried out.     

Synthesis and Extended 3D Hydrogen-bonded Structure of Complex Tris(violurato-N,O) Cobalt(III) Hexahydrate

1 INTRODUCTION The study of cobalt complexes plays an important role in pharmacology, coordination chemistry and bio- inorganic chemistry. The recent work on organoco- baloximes shows that it has outgrown its initial rele- vance of Vitamin B12 model and acquired an indepen- dent research field because of its rich chemistry[1~4]. At the same time, research on the complexes with oxime ligands has considerable interest owning to their special catalytic, electric, magnetic properties and bio…     

Synthesis and Characterization of Tris(tetraethylammonium) Pentacyanoperoxynitritocobaltate(III)

We report the first synthesis of a stable complex of peroxynitrite coordinated to a transition‐metal ion. Solid tris(tetraethylammonium) pentacyanosuperoxocobaltate(III) reacts with 1 equiv. of gaseous nitrogen monoxide to yield tris(tetraethylammonium) pentacyanoperoxynitritocobaltate(III) ( 1 ). This novel complex is characterized by a UV absorption band at 280 nm (ε≈2000 M ⁻¹ cm⁻¹) in H₂O. The IR spectrum of the sodium salt of the complex, 2 , shows vibration bands due to peroxynitrite. Nitrated and hydroxylated products are observed when the complex is dissolved in H₂O in the presence of phenol. The rate constant of hydrolysis is k=4.9×10⁻⁶ s⁻¹. The complex is less stable in MeCN and in MeOH and perhaps reacts with these solvents.     

Tris(2,6-dimethoxyphenyl)antimony Diazide: Synthesis and Structure

Tris(2,6-dimethoxyphenyl)antimony diazide has been synthesized and characterized by X-ray diffraction. The antimony atoms in four crystallographically independent molecules have a distorted trigonal pyramidal coordination. Axial angles range within 174.57°–178.95°.     

Tris(3-fluorophenyl)antimony Dihalides: Synthesis and Structure

Russian Journal of General Chemistry - Tris(3-fluorophenyl)antimony dichloride, dibromide, and diiodide were obtained by the reaction of tris(3-fluorophenyl)antimony with chlorine, bromine, and...     

Synthesis and Structure of Tris (methylcyclopentadienyl)Praseodymium

1INTRODUCTIONThestructuralvariationsofbase-freerareearthcomplexes,R3Ln(R=cy-clopentadienylorsubstitutedcyclopentadienyl),areoftenstronglyinf1uencedbythenatureofsubstituentsonthecyclopentadienylringandtheradiusofcentralmet-alt1-6i.Forthesamemetalcompounds,theirstructuresdisplaysubstantialvariationswhenthesizeandpropertiesofthesubstituentoncyclopentadienylringarechanged.[4all6iInordertogainabet1erunderstandingofthediversevarietyofthestructuresofsubstitutedcyclopentadienyllanthanidecomplexe…     

Imidotitanium Tris(pyrazolyl)hydroborates: Synthesis, Solution Dynamics, and Solid-State Structure

Reaction of [Ti(NBu(t))Cl(2)(py-Bu(t))(2)] (1; py-Bu(t) = 4-tert-butyl pyridine) with 1 equivalent of K[Tp(Me2)], K[Tp(Pri)] or K[Tp(Pri,Br)] affords the corresponding complexes [Tp(Me2)Ti(NBu(t))Cl(py-Bu(t))] (2), [Tp(Pri)Ti(NBu(t))Cl(py-Bu(t))] (3), and [Tp(Pri,Br)Ti(NBu(t))Cl(py-Bu(t))] (4), respectively, which are the first examples of imido Group 4 tris(pyrazolyl)hydroborates [Tp(Me2) = tris(3,5-dimethylpyrazolyl)hydroborate; Tp(Pri) = tris(3-isopropylpyrazolyl)hydroborate; Tp(Pri,Br) = tris(3-isopropyl-4-bromopyrazolyl)hydroborate]. Complexes 2-4 are fluxional on the (1)H and (13)C NMR time scales, the spectra indicating restricted rotation about the Ti-py-Bu(t) bond. Activation parameters for this dynamic process have been determined both by (13)C NMR lineshape analysis and by coalescence measurements. The solution-state structure for 2 has been unambiguously assigned from a low temperature, phase-sensitive (1)H NOESY DQF spectrum and the solid-state X-ray crystal structure of the dichloromethane solvate of 3 has been determined (space group P2(1)/n; a = 12.539(3), b = 14.686(3), c = 21.747(4) ?; beta = 91.28(3) degrees; R(1) = 0.0694 and wR(2) = 0.154 for 1578 observed reflections). (13)C NMR Deltadelta values (Deltadelta = delta(C(alpha)) - delta(C(beta))) for the tert-butyl imido ligand in 2-4 suggest that the donor ability of the tris(pyrazolyl)hydroborate ligands increases in the order Tp(Pri,Br) < Tp(Pri) < Tp(Me2). None of these ligands, however, is as effective a donor to the metal center as either eta-C(5)H(5) or eta-C(5)Me(5).