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.     

Synthesis and Crystal Structure of Cobalt(Ⅲ) Tris(diethyldithiocarbamato) Complex

1INTR0DUCTI0NRecently,thedesignandsynthesisofdinuclearcomplexeshavebeenafascinat-ingareaofresearchowingt0theirimportanceinbasicandappliedchemistry"'.Par-ticularintersthasdevelopedindinuclearcomplexesasmodelsformeta1loproteins"'.Inanattempttosynthesizethetypeof[Ln(S,CN(C2H,)2)3j[Co(S2CN(C2H5)2)2jdinuc1earcomplex,thepurefinecrystalsofCo[S2CN(C2H5)2)2)3were0btained.2EXPERIMENTAL2'1Preparation0fC0[S,CN(C,H,),j,TotheclearsolutionoftheanhydrousSmCl3(0.5mmol)in5mLanhydrousethanolw…     

Synthesis of bis(diethyldithiocarbamato)manganese(II) and tris(diethyldithiocarbamato)manganese(III)

An ideal undergraduate introduction to the challenges of synthesis and characterization of air-sensitive compounds is accomplished in the preparation of bis(diethyldithiocarbamato)manganese(II). This economical experiment employs a glovebag, low-cost and low-toxicity chemicals, and is completed in one undergraduate laboratory period. For comparison purposes, the synthesis and characterization of air-stable tris(diethyldithiocarbamato)manganese(III) is also described.     

Solvent and Temperature Dependence of 59Co NMR Chemical Shifts of Tris(acetylacetonato)cobaIt(III) and Tris(dipivaloylmethanato)cobalt(III)

Cobalt-59 NMR chemical shifts of Co(acac)₃, and Co(dpm)₃ (acac^– = acetylacetonate ion and dpm^– = dipivaloylmethanate ion) in 14 organic solvents, C₆H₁₄, C₆H₆, CH₂Cl₂, CHCl₃, CCl₄, CH₃CN, CH₃OH, C₂H₅OH, CH₃CH(OH)CH₃, (C₂H₅)₂O, (CH₃)₂CO, (CH₃)₂SO, (CH₃)₂NCHO and C₆H₅NO₂, were measured at five temperatures ranging from 289 to 329 K. The observed chemical shift (_obs) was linearly correlated to the maximum absorption wavelength in the visible spectra (_max) corresponding to the d-d electronic transition energy between the ground ¹A_1g and excited ¹T_1g states. The _obs-_max relation was explained by the ligand field theory. The temperature coefficients of _obs, of each complex showed a negative correlation with _obs. The _obs, of Co(acac)₃ decreased with the increasing electrophilic ability of the solvent (Mayer's acceptor number), whereas no tendency was observed in the case of Co(dpm)₃.     

三(对乙酰基苯基)甲烷的合成及表征

以三苯甲烷（TPM）和乙酰氯为原料,以无水三氯化铝为催化剂,二氯乙烷为溶剂,经过乙酰化反应得到三（对乙酰基苯基）甲烷（TAcPM）．讨论了原料配比、溶剂、温度和后处理等因素对产率的影响,并采用红外、核磁及元素分析对TAcPM的结构进行了表征．     

Synthesis and spectral properties of cobalt(II) and cobalt(III) tetraarylporphyrinates

Reactions of 5,10,15,20-tetraphenylporphin, 5,10,15,20-tetra(4′-methoxyphenyl)porphyrin, and 5,10,15,20-tetra(4′-chlorophenyl)porphyrin with cobalt(II) acetate in dimethylformamide were studied by spectrophotometry. The corresponding cobalt(II) porphyrinates were synthesized and identified. The corresponding cobalt porphyrinates in +3 oxidation state were obtained by reaction of cobalt(II) 5,10,15,20-tetraphenylporphyrinate and cobalt(II) 5,10,15,20-tetra(4′-methoxyphenyl)porphyrinate with 2,3-dichloro-5,6-dicyano-p-benzoquinone in chloroform. The oxidation of cobalt(II) 5,10,15,20-tetra(4′-chlorophenyl)porphyrinate with hydrochloric acid in dimethylformamide leads to cobalt(III) porphyrinate.     

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).     

Die Kristallstruktur von Tris(N,N-diethyl-N′-benzoylselenoureato)cobalt(III)

The Crystal Structure of Tris(N,N-diethyl-N′-benzoylselenoureato)cobalt(III) Co(C₁₂H₁₅N₂OSe)₃ crystallizes in the trigonal space group P3 . The cell parameters are a = 16.697(4), c = 8.557(8) Å, Z = 2. The structure was solved with Patterson and direct methods and was refined to a final R-value of 4.59%. Co^III is bidentally coordinated to three N,N-diethyl-N′-benzoylselenourea molecules to form a distorted octahedron with facial arrangement of the selenium and oxygen donor atoms. The Co? Se and Co? O bond lengths are 2.328(2) and 1.943(6) Å, respectively. The arrangement of the molecules within the unit cell leads to the formation of hexagonal channels parallel to the crystallographic c-axis. The wall of the channels is formed by carbon atoms of the phenyl group. The diameter of the channels is 8.148 Å.     

Synthese und Röntgenstrukturanalyse von Tris(diethyldithiocarbamato) dimethylphenylphosphantechnetium(III), einem Technetium-Komplex mit der Koordinationszahl 7

Preparation and Crystal and Molecular Structure of Tris(diethyldithiocarbamato)dimethylphenylphosphinetechnetium (III) The title compound Tc(S₂CNEt₂)₃(Me₂PhP) I has been prepared by the reaction of TcCl₃(Me₂PhP)₃ with NaS₂CNEt₂. The crystal structure of I has been determined by single-crystal X-ray diffraction methods at room temperature. Crystals are rhombic, space group P2₁2₁2₁, with a = 8.708(1), b = 12.012(1), c = 29.626(3) Å and Z = 4. The compound consists of discrete I molecules. The technetium atom has a seven-coordinated environment which is best described as a distorted pentagonal bipyramid. The Tc—P distance (2.330(3) Å) is remarkably short compared with other technetium complexes with mono-dentate phosphine ligands.     

Limiting interdiffusion coefficients of Tris(acetylacetonato)cobalt(III) in water and in organic solvents

The diffusion coefficients of tris(acetylacetonato)-cobalt(III) in water (5, 15, 25, and 40°C), methanol (25°C), ethanol (15, 25, and 45°C), 1-propanol (25°C), 1-butanol (45°C), acetone (25 and 40°C), 2-butanone (25°C), acetonitrile (25°C), tetrahydrofuran (25°C), benzen (25°C), toluene (25°C), and carbon tetrachloride (25°C) have been measured at concentrations close to infinite dilution. The Stokes-Einstein coefficient (f=kT/Dr) has been calculated for Co(acac)₃ in each solvent and is found to be larger in water than in organic solvents. Furthermore, it increases as the temperature is lowered (or as the viscosity is increased) in water while it decreases with increasing viscosity of organic solvents. The differences are discussed in terms of the enhancement of the water structure by the solute.     

Synthesis of Cellulose Tris (4-Methylbenzoate) as Gas Chromatographic Stationary Phase and its Characterization

Cellulose (MC) is the most accessible optically active polymer. Its benzoate and phenylcarbamate derivatives exhibit a high chiral recognition ability for a variety of racemic compounds as chiral stationary phases (CSPs) for high performance liquid chromatography1-3. However, the application of cellulose derivatives in gas chromatography has seldom been reported except that Zou reported cellulose tribenzoate (CTB) which was used as a stationary phase for gas chromatography 4. Cellulose and…     

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%。