Kinetic Modelling of the Concentrations of the Stabilizer DPA and Some of Its Consecutive Products as Function of Time and Temperature

By kinetic modelling of the possible reactions of diphenylamine (DPA) and its nitrated consecutive products used to stabilize cellulose nitrate (CN), one can get reactivities for the nitrated DPA compounds for the situation inside a real CN formulation and therewith determine their stabilizing contribution. Concentration data of DPA and seven of its consecutive products have been determined by HPLC from isothermal ageing of a CN formulation at temperatures between 65 and 90°C for up to 344 days. A comparison between the modelling presented and modellings published in the literature using the steady-state approximation is made. The steady-state approximation oversimplifies the stabilizer reaction behaviour in a CN formulation. From the applied modelling the question about N—NO—DPA as a key intermediate can be answered.This revised version was published online in November 2005 with corrections to the Cover Date.     

二苯胺磺酸钠还原法制备粒径可控的金纳米粒子

采用二苯胺磺酸钠还原四氯合金酸的方法,在室温条件下,用SDS(十二烷基硫酸钠)、SDBS(十二烷基苯磺酸钠)作表面活性剂,成功地合成了金纳米粒子.分别讨论了还原剂二苯胺磺酸钠、表面活性剂(SDS、SDBS)及四氯台金酸的浓度等对金纳米粒子的粒径和形貌的影响.通过控制反应条件,可以合成出平均粒径大约为10、14、30、36nm的金纳米粒子.利用透射电镜(TEN)、紫外-可见(UV-Vis)吸收光谱对金纳米粒子进行了表征.研究结果表明不同的SDS或SDBS/HAuCl4的摩尔比,对金纳米粒子的尺寸大小有影响.     

High-yield Synthesis of Branched Gold Nanocrystals by a Sodium Diphenylamine-4-Sulfonate Reduction Process in Polyethylene Glycol Aqueous Solution

For developing new excellent electrocatalysts toward methanol and oxygen, branched Au nanocrystals have been prepared in high yield by the reaction of HAuCl₄ and sodium diphenylamine‐4‐sulfonate in the presence of PEG (polyethylene glycol) at room temperature. When the amount of PEG was in the range of 1–3 mL, branched Au nanocrystals were all obtained, and the amounts of sodium diphenylamine‐4‐sulfonate and HAuCl₄ had no obvious effect on the morphology of gold nanocrystals. PEG molecules play an important role in the formation of branched gold nanocrystals. The nanocrystals were characterized by transmission electron microscopy (TEM), selected area electron diffraction, high‐resolution transmission electron microscopy (HRTEM) and UV‐Vis absorption spectrum. HRTEM research suggests that the tips of gold nanocrystals grow selectively in the [111] directions. The UV‐Vis absorption spectrum displays two‐separated surface plasmon resonance peaks.     

二苯胺与邻氨基酚共聚的原位紫外-可见光谱电化学研究

运用循环伏安法(CV)和原位紫外-可见光谱电化学法研究了二苯胺(DPA)和邻氨基酚(OAP)在4mol/L H2SO4中单独聚合及二者共聚的电化学过程。DPA和OAP单独聚合及二者共聚时不同的电化学行为表明DPA和OAP之间发生了共聚作用。原位紫外-可见光谱研究表明,在DPA与OAP的共聚过程中,DPA与OAP首先被氧化生成阳离子自由基,然后,两者的阳离子自由基与溶液中的DPA和OAP单体或其自由基发生交互反应产生混合二聚物中间体,其吸收峰位于508 nm处。进一步研究发现,DPA和OAP的共聚过程与溶液中各单体的浓度比有关。     

不等性双枝有机分子的合成及其光学性质

以N-乙基二苯胺为母体,通过Vilsmeier反应、碘化、Heck反应和无溶剂Wittig反应合成了新的不等性双枝有机分子(5),其结构经1H NMR, IR, MS和元素分析表征.研究了5在7种溶剂中的紫外可见吸收和荧光发射性质.     

Spectral and photochemical properties of bifunctional compounds and their charge-transfer complexes. Derivatives of diphenylamine

Spectral properties of diphenylamine (DPA) derivatives Ph₂N-(CH₂) _n -NPh₂ (n = 1, 3, 5, and 9) and their charge-transfer complexes with CBr₄ have been studied. The interaction of two Ph₂N groups results in hypsochromic shifts of absorption bands and changes in their intensities in spectra of diamines whenn = 1 and 3 compared to the spectra ofN-alkyl-substituted derivatives of DPA. The spectrum of the diamine complex whenn = 1 is shifted hypsochromically, while those of the other diamine complexes are shifted bathochromically relative to the spectrum of theN-methyldiphenylamine complex. The positions of absorption maxima in the spectra correlates with the values of redox potentials of amines. Irradiation at the charge-transfer band ( 365 nm) of complexes between diamines and CBr₄ results in the formation of dyes, which absorb at 550 to 700 nm and presumably have di- and triphenylmethane structures.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1725–1730, September, 1995.This work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-08673).     

KF—Al2O3催化二苯胺的苄基化

氟阴离子(主要指无水碱金属氟化物、它的季铵盐及其载体试剂)作为一种碱性催化剂,近年在有机合成中的应用得到迅速发展。与其它催化剂比较有下述优点:反应条件温和、催化活性好、选择性强、后处理简单、产率高且可再生重复使用。     

Acridine-based ligands from cobalt(II) mediated rearrangement of diphenylamine-based starting materials

The synthesis and characterisation of two cobalt(II) complexes, [Co^IIL^Br-acrCl₂] (1a) and [Co^IIL^H-acrCl₂] (1b), with acridine head-units resulting from an unexpected ligand rearrangement from a diphenylamine head-unit, and the intended cobalt(II) complex, Co^IIL^Br-dpa(Cl)(H₂O) (2), are reported. Single crystals of the two dark green acridine-based cobalt(II) complexes, 1a and 1b, form in a one-pot reaction of cobalt(II) chloride, the chosen diphenylamine-2,2′-dicarboxaldehyde (Ia 4,4-′dibromo- or Ib unsubstituted), triethylamine and two equivalents of 2,4-dimethylaniline in acetonitrile, in 23% yield. In contrast, the intended diphenylamine-based complex was isolated in two steps: first isolation of the Schiff base ligand, then complexation with cobalt(II) chloride and deprotonation with potassium tert-butoxide, in methanol/dichloromethane, giving 2 as a bright yellow solid in 67% yield. All three complexes feature cobalt(II) centres, with N₂Cl₂ approximately tetrahedral coordination for 1a and 1b confirmed by single crystal structure determinations. It is proposed that after one imine ‘arm’ forms, cobalt(II) coordination facilitates the other aldehyde undergoing an intramolecular cyclisation to form the new heterocyclic acridine head-unit. The structures of both of the resulting acridine-based complexes, 1a and 1b, and that of the originally intended Schiff base ligand, HL^Br-dpa, were confirmed by single-crystal X-ray diffraction. These are the first examples of complexes of an acridine ligand of this type.     

多溴代二苯胺热力学性质的密度泛函理论研究

在B3LYP/6-31G*水平上对209个多溴代二苯胺(PBDPA)系列化合物进行了全优化和振动分析计算, 得到各分子在298.15 K, 101.3 kPa标准状态下的热力学参数. 设计等键反应, 计算了PBDPA系列化合物的标准生成热(ΔfHÖ)和标准生成自由能(ΔfGÖ). 研究了热力学参数SÖ与溴原子的取代位置及取代数目(NPBS)之间的关系, 结果表明: PBDPA系列化合物的SÖ, ΔfHÖ和ΔfGÖ与NPBS之间有很强的相关性(R2≥0.984). 根据异构体标准生成自由能的相对大小, 从理论上求得异构体的相对稳定性. 以Gaussian 03程序的输出文件为基础, 采用统计热力学程序计算了PBDPA化合物在200 K至1000 K的摩尔恒压热容(Cp,m), 并用最小二乘法求得Cp,m与温度之间的相关方程, 发现Cp,m与T, T－1和T－2之间有着很好的相关性(R2＝1.000).     

The influence of surfactants on the acid—base and redox properties of reagents of the diphenylamine series

The influence of aqueous solutions of surfactants on the redox and acid—base properties of diphenylamine redox reagents was studied by potentiometric titration and UV spectroscopy. The formal redox potentials, the pK _a values of the reagents in aqueous solutions and in the presence of surfactants, and the constants of binding of the reagents by micellar solutions of surfactants were estimated. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1386–1388, August. 2000.