Synthesis,Crystal Structure and Properties of A Triphenyltin Schiff Complex with Salicylidene-2-aminophenol

The triphenyltin complex with salicylidene-2-aminophenol （C31H24NO2Sn, 1） has been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and X-ray single-crystal diffraction. The complex crystallizes in monoclinic system, P21/c space group with a = 1.09515（8）, b = 1.17739（8）, c = 2.29075（14） nm, β = 117.070（4）°, V = 2.6302（3） nm3, Z = 4, Dc = 1.417 g/cm3, ？ = 0.999 mm–1, F（000） = 1123, R = 0.0472 and wR = 0.1169. X-ray single-crystal diffraction showed that 1 demonstrates a one-dimensional chain structure. The quantum chemical calculation of 1 has been investigated. Complex 1 emits fluo- rescence at 558 nm and exhibits certain inhibitory activity against NCI-H460, A549 and MCF-7.

SYNTHESIS,CHARACTERIZATION,THERMAL DEGRADATION AND ELECTRICAL CONDUCTIVITY OF OLIGO[2-(2-HYDROXYPHENYLIMINOMETHYLBENZYLIDENE)AMINOPHENOL]AND OLIGOMER-METAL COMPLEXES

The oxidative polycondensation reaction conditions of 2-[(2-hydroxyphenyliminomethylbenzylidene)amino- phenol](2-HPIMBAP)has been accomplished by using air O_2 and NaOCl oxidants in an aqueous alkaline medium between 50-90℃.The optimum reaction conditions of the oxidative polycondensation and the main parameters of the process were established.At the optimum reaction conditions,yield of the products were found to be 67.72% and 61.49% for air O_2 and NaOCl oxidants respectively.The structures of the monomer ...

SYNTHESIS,CHARACTERIZATION,THERMAL DEGRADATION AND ELECTRICAL CONDUCTIVITY OF OLIGO[2-(THIEN-2-YLMETHYLENE)AMINOPHENOL]AND OLIGOMER-METAL COMPLEXES

The optimum reaction conditions of the oxidative polycondensation of 2-(thien-2-yl-methylene)aminophenol (2-TMAP) has been accomplished by using air O_2,H_2O_2 and NaOCl oxidants in an aqueous alkaline medium between 20℃and 90℃.The structures of the monomer and oligomer were confirmed by FT-IR,UV-Vis,~1H-NMR and ^(13)C-NMR and elemental analysis.TGA-DTA,size exclusion chromatography(SEC) techniques and solubility tests were applied for characterization.The ~1H-NMR and ^(13)C-NMR data show that the polymeriz...

Zinc Complexes of New Chiral Aminophenolate Ligands: Synthesis, Characterization and Reactivity toward Lactide

The syntheses of a library of new chiral aminophenolate bidentate O,N-type ligands HOC6H4(2-R- 4-R′)CH2N(Me)CH(Me)C6H5 [R = R′ = But, 1;R = R′ = Pent, 2;R = But, R′ = Me, 3;R = Me, R′ = But, 4;R = R′ = Me, 5] and tridentate O,N,O-type ligands HOC6H4(2,4-But)CH = NCH(R′′)C6H5 [R′′ = Me, 6;R′′ = CH2OMe, 7] are reported. These ligands were characterized by elemental analysis, nuclear magnetic resonance spectroscopy (1H & 13C), and single crystal X-ray diffraction. These ligands serve as chiral auxiliaries for inorganic chemists to design chiral metal-based complexes for asymmetric catalysis and stereoselective polymerization reactions. Three new heteroleptic zinc complexes based on these ligands have been synthesized in moderate yields via a ligand-exchange transamination reaction between homoleptic [Zn(N(SiMe3)2)2] and one equivalent of corresponding ligands to afford [L3ZnN- (SiMe3)2] (3a), [L4ZnN(SiMe3)2] (4a), and [L7ZnN(SiMe3)2] (7a). Solvent-free polymerization of raclactide at 130°C using these zinc compounds yielded atactic polylactides with Mw 10,000 g/mol and narrow polydispersity of 1.3.

Theoretical Study on the Reaction Mechanism of o-Aminophenol, Acetic Acid and Phosphorus Oxytrichloride One-pot to Form 2-Methyl Benzoxazole

The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the GGA/PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Two possible reaction pathways were investigated in this study. The result indicates that the reaction Re→TS1→IM1→TSA2→IMA2→TSA3→IMA3→TSA4→IMA4→TSA5→P2 is the main pathway, the activation energy of which is the lowest. Re→TS1→IM1 is the rate-limiting step, with the activation energy being 221.54 kJ·mol;and the reaction heat being 10.06 kJ·mol;. The dominant product predicted theoretically is in agreement with the experiment results.

Quality Control of Paracetamol Generic Tablets Marketed in Benin and Search of Its Two Impurities P-Aminophenol and P-Nitrophenol by HPLC-UV/Visible

In this work, we evaluated the quality of paracetamol generic tablets while seeking its two main impurities namely 4-para-aminophenol (4-AP) and 4-para-nitrophenol (4-NP) which have nephrotoxic and teratogenic properties. Ninety-four (94) samples were collected at various levels of the medicine supply chain and illegal markets in Benin for quality control tests such as visual inspection, pharmacotechnical tests as mass variation, disintegration test, dissolution test, followed by HPLC UV-Vis identification and assay of paracetamol, 4-AP and 4-NP. The analytes were separated on C18 Lichrocart column (250 mm × 4.0 mm i.d, 5 μm);the mobile phase was MeOH:10 mM ammonium acetate buffer pH 6.8 (35:65) pumped at a flow rate of 1 ml/min. The detection was done at 245 nm. Analysis of our results shows that 77.7% of the samples did not comply with the visual inspection test requirements, 2.1% did not pass the mass variation test, 24.3% of the sample batches didn’t comply with the disintegration test requirements. In addition none of these uncomply batches passed the dissolution test, even if the identification test indicated that all samples contained paracetamol. None contained 4-NP (acceptance limit < 0.05% m/m;BP), while 3 of 94 samples contained 4-AP but within acceptance limit (4-AP < 0.1% m/m;BP). As for the paracetamol assay, 80.9% complied with the specifications of the pharmacopoeias taken as reference (90% - 110%;USP). Further, broader studies should be conducted according to the same rules of good practice for a more comprehensive analysis of the situation. Generally the quality control of paracetamol in most African countries, particularly in Benin, is based on pharmacotechnical tests and paracetamol assay. This work, in addition to the usual tests, showed the importance to search for paracetamol and other drugs’ impurities during their routine quality control.

Non-Conducting Poly(O-Aminophenol) Films in the Field of the Bioelectrochemistry

The practical use of non-conducting poly(o-aminophenol) (POAP) films in the field of the bioelectrochemistry is discussed in this paper. Particular emphasis is given to the effects of applied potential, solution pH and interferents on the response current of biosensors based on POAP.

Spectroscopic and molecular structure characterization of the bis(2-aminophenol)(5, 10, 15, 20-tetraphenylporphyrinato) cobalt(II) complex

The reaction of the cobalt(II) meso-tetraphenylporphyrin (TPP) starting material with an excess of 2-aminophenol (Hon) in organic solvents, yields the cobalt(II) porphyrin species [CoII(TPP)(Hon)2] (1). This compound has been characterized by UV-vis., IR, MSI MS and 1H NMR spectroscopy. The UV-vis data and especially the proton NMR results, for the isolated product, indicated that complex 1 is a Co(II) mesoporphyrin derivative.The X-ray molecular structure of the title compound bis(2-aminophenol) (tetraphenylporphyrinato) cobalt(II) has been determined. This structure is the first one reported of a metalloporphyrin with a 2-aminophenol axial ligand species. The central metal is hexacoordinated by the four nitrogen atoms of the pyrrole rings and the nitrogen atoms of the two Hon trans axial ligands.

Permselectivity of 4－Aminophenol，Paracetanol and Phenacetin on the Self－Assembled n－Alkanethiol Monolayer Modified Gold Electrode

The gold electrodes coated by n-alkanethiol with various chain lengths were used to study the permeability of uric acid,ascorbic acid,4-aminophenol,paracetanol and phenacetin by means of linear sweep voltammetry.The results show that the optimum chain length is n=10.The improvements in the selectivity and the stability of the amperometric detection of these compounds in a flow stream were obtained by n-alkanethiol self assembled monolayers modified electrodes based on their differences in the hydrophobicity and the permeability.

Reactive Extraction of o-Aminophenol Using Trialkylphosphine Oxide

Extraction of o-aminophenol (OAP) using trialkylphosphine oxide (TRPO) was studied with different diluents. The neutral OAP was extracted using TRPO under an equilibrium pH in the range of 6—7.5, and a maximum distribution coefficient occurred. It was confirmed that the pH value and the TRPO concentration are the key factors that affect dis-tribution coefficient. Nonpolar diluents could provide better extraction distribution coefficient for the extraction of OAP and the order is: kerosene >n-octanol >chloroform.

RECOVERY OF p-AMINOPHENOL (PAP) FROM AQUEOUS SOLUTION BY HYPER-CROSS-LINKED RESIN AND ITS USE FOR WASTEWATER TREATMENT

p-Aminophenol (PAP), a typical amphoteric compound, has been widely used as raw chemical material and important intermediate in various fields. To study on the recovery of PAP, an experimental comparison of the adsorption and desorption properties of PAP onto three types of hyper-cross-linked resins in aqueous solutions was performed. This paper focuses on the static equilibrium adsorption and desorption behaviors, the adsorption thermodynamics, the column dynamic adsorption and desorption, and other influencing factors of adsorption, such as temperature and pH values. All the isothermal data fit well to the Freundlich model. The capacity of equilibrium adsorption for PAP on NG-10 is the highest within the temperature range 288K^318K,which may greatly contribute to the advantage in specific surface area, especially the micropore area, of the adsorbent. While in the desorption experiments, NG-9 achieved relative well regeneration efficiency whether by ethanol or by 4% hydrochloric acid. Furthermore, the results of column tests and field applications were also proved that NG-9 was an effective sorbent for the reclamation PAP from wastewater.

Synthesis of bifunctional Pt/MgAPO-5 catalysts and their catalytic performance in the hydrogenation of nitrobenzene to p-aminophenol

MgAPO-5 molecular sieves have been synthesized using diethylaminoethanol as the templating agent in a wide range of the MgO/Al2O3 ratio.The samples were characterized by XRD,SEM,solid state NMR,FT-IR and NH3-TPD.Using MgAPO-5 as acidic supports,bifunctional Pt/MgAPO-5 catalysts were prepared for hydrogenation of nitrobenzene to p-aminophenol (PAP).The results showed that the MgO/Al2O3 ratios influenced the Mg content and the acidity of MgAPO-5 samples,thereby greatly affecting the catalytic performance of Pt/MgAPO-5 catalysts.The selectivity to PAP over Pt/MgAPO-5 was dependent on the amount of strong acid sites of MgAPO-5.When the MgO/Al2O3 molar ratio was 0.5,the synthesized MgAPO-5 sample exhibited the largest amount of strong acid and a highest PAP yield of 41.1% was achieved over Pt/MgAPO-5 catalyst.

Synthesis and characterization of aminophenolate-ligated rare-earth metal amide complexes and their catalytic activity for lactides polymerization

Amine elimination of Ln[N(SiMe3)2]3(μ-Cl)Li(THF)3 with aminophenol H[ON]{H[ON]=2-(CH2 NC5 H10)-4,6-tBu2-C6 H3OH}in 1:2 molar ratio in THF gave the monometallic rare-earth metal amide complexes[ON]2 LnN(SiMe3)2(Ln=Yb(1),Y(2),Gd(3),Sm(4),Nd(5))in 57%-73%isolated yields.All these complexes were characterized by elemental analysis.The molecular structures of complexes 1-4 were determined by single crystal X-ray diffraction.These complexes are highly active for L-Iactide polymerization to give high molecular weight polymers with unimodal molecular weight distributions.In addition,these complexes can also initiate rac-lactide polymerization with high activity to afford heterotactic-rich polylactides.

Determination of tetraethyl ammonium by ion-pair chromatography with indirect ultraviolet detection using 4-aminophenol hydrochloride as background ultraviolet absorbing reagent

A method was developed for the determination of tetraethyl ammonium （TEA） by reversed-phase ion- pair chromatography with indirect ultraviolet detection, Chromatographic separation was achieved on a reversed-phase C18 column using background ultraviolet absorbing reagent - ion-pair reagent - organic solvent as mobile phase. The effects of the background ultraviolet absorbing reagents, detection wavelength, ion-pair reagents, organic solvents and column temperature on the determination method were investigated and the retention rules discussed. Results found that TEA could be successfully analyzed by using 0.7 mmol/L 4-aminophenol hydrochloride and 0.15 mmol/L 1-heptanesulfonic acid sodium mixed with 20% （v/v） methanol as mobile phase at a UV detection wavelength of 230 nm. Under these conditions, the retention time of tetraethyl ammonium was 2.85 min. The detection limit （S/N = 3） for TEA was 0.06 mg/L. The relative standard deviations （n = 5） for peak area and retention time were 0.35% and 0.02%, respectively. The method has been successfully applied to the determination of synthesized tetraethyl ammonium bromide. Recovery of tetraethyl ammonium after spiking was 99.1%.

基于Pt-PDDA/还原石墨烯纳米电极材料的构建及电化学检测4-氨基苯酚

通过Hummer法将天然石墨粉氧化得到氧化石墨,再将其超声分散于去离子水中形成稳定的氧化石墨分散液。为了引入铂粒子并使之与氧化石墨烯片牢固锚定,将氧化石墨分散液与氯铂酸溶液混,合成Pt-PDDA/还原石墨烯(Pt NPs-PDDA/rGO)纳米电极材料。通过红外、紫外光谱分析以及扫描循环伏安曲线、交流阻抗曲线对该复合电极材料进行了表征。由于铂优良的催化性能,聚二烯丙基二甲基氯化铵(PDDA)的防聚合功能,石墨烯巨大的表面积、优异的电子传导性能及对4-氨基苯酚(4-AP)强大的吸附作用,将制备得到的Pt-PDDA/还原石墨烯纳米电极材料构建电化学传感器,用于对4-AP超灵敏的检测。结果表明,在0.5 mol/L的磷酸盐缓冲液(PBS)中对不同浓度的4-AP进行测定,Pt NPs-PDDA/rGO复合膜修饰的GCE与裸露的GCE和功能化石墨烯(PDDA-rGO)修饰的GCE相比,4-AP的氧化还原峰电流显著增加,表明Pt NPs-PDDA/rGO具有对4-AP的电催化活性。然后对实验条件进行了优化,研究了不同实验条件对电化学传感器性能的影响。结果表明,在最理想的条件下,4-AP浓度在1.00×10^(-5)~1.00×10^(-3)mol/L范围内时,氧化峰电流与浓度呈良好的线性关系,相关系数为0.992 2。最后将其应用于河水和自来水中的4-AP检测,获得令人满意的结果,回收率为98.0%~106.0%。

Synthesis of Chiral Aminophenols Based on Proline and Their Application in Enantioselective Addition of Diethylzinc to Aldehydes

Three 2-{(3R, 7aS)-1, 1-disubstituted-tetrahydro-1H-pyrrolo [1,2-c][1,3]oxazol-3-yl} phenols have been synthesized from salicylaldehyde and amino alcohols derived from L-proline, and used as ligands hi enantioselective addition of diethylzinc to aldehydes, the ee values of obtained secondary alcohols were found in the range of 0-90%.

Study on Free Radicals Produced During the Photolysis of p-aminophenol in Aqueous TiO_2 Suspension

Recently, study on the photocatalytic degradation of harmful substances by usingsemiconductors has received much attention,because semiconductors, as a stable andinexpensive photocatalyst, may be effective for the degradation of pollutants from the stand-point of solar energy utilization, e.g. TiO2, the photoinduced holes with high oxidationpotential, may be used as strong oxidant to decompose a large number of

Synthesis and Structure of Inclusion Complex of Cyclomalto- heptaose (β-Cyclodextrin) with m-Aminophenol

The supramolecular compound, β-CD/m-aminophenol[(C_(42)-H_(70)O_(35))·(C_6H_7ON)·(H_2O)_(7.5)·CH_3OH], was synthesized and characterized byX-ray diffraction analysis. It crystallizes in monoclinic system, P2_1 space group, with a =1.5122(4) nm, b = 1.0335(4) nm, c = 2.0915(3) nm, β= 109.58(2)°, V = 3.0798(3) nm^3 and final R =0.0598. The system belongs to ' shallow inclusion' which is rarely found. In this supramolecule, theguest is located over the narrow rim of the host. There are so many hydrogen bonds that they builda dense hydrogen bond net. The hydrogen-bond interactions are the main force to form the wholesystem and keep the stability.

Supported bimetallic catalyst Pt-Pb/SiO2 for selective conversion of nitrobenzene to p-aminophenol in pressurized CO2/H2O system

Various supported Pt-Pb bimetallic catalysts were prepared and applied for the catalytic conversion of nitrobenzene to p-aminophenol in the environmentally benign pressurized CO2/H2O system.Among the bimetallic catalysts prepared,Pt-Pb/SiO2 is the best and nitrobenzene could be converted to paminophenol with a selectivity as high as 82% when the reaction was carried out using this catalyst at110 ℃ under 5 MPa CO2 and 0.2 MPa H2.