Reaction of Red Phosphorus with 4-Methoxystyrene in KOH-DMSO System: One-Pot Synthesis of Tris[2-(4-methoxyphenyl)ethyl]phosphane Oxide

Abstract

Red phosphorus reacts with 4-methoxystyrene in the KOH-DMSO superbase system (130 °C, 3 h, Ar) in the presence of a small quantity of H₂O to give tris[2-(4-methoxyphenyl)ethyl]phosphane oxide as the main product in 30% yield. Microwave activation of the reaction (600 W, 6 min) affords basically a mixture of the phosphane oxide and tris[2-(4-methoxyphenyl)ethyl]phosphane (in a ratio of 1:1). When the mixture is exposed to air (r.t., 24 h), the phosphane oxide is formed in 85% yield.

GRAPHICAL ABSTRACT     

Reaction of Red Phosphorus with Electrophilic Reagents in Superbasic Systems

Abstract

A new method for generating highly nucleophilic ions from red phosphorus in superbasic systems, such as alkali metal hydroxide-dipolar aprotic solvent (HMPA, DMSO) or solvent of moderate polarity (toluene) with or without a phase-transfer catalyst, has been developed and shown to cover non-standard convenient routes to triorganylphosphines, -phosphine oxides and their derivatives. This is illustrated by the following examples:     

Reactions of Elemental Phosphorus and Phosphine with Electrophiles in Superbasic Systems: XIV.1 Phosphorylation of 2-Vinylnaphthalene with Elemental Phosphorus and Phosphines in the KOH-DMSO System

Elemental phosphorus (red or white) reacts with 2-vinylnaphthalene while heating at 90-96°C in the superbasic KOH-DMSO system to form 2-(2-naphthyl)ethylphosphine, 2-(2-naphthyl)ethylphosphinic acid, bis[2-(2-naphthyl)ethyl]phosphine, bis[2-(2-naphthyl)ethyl]phosphine oxide, and tris[2-(2-naphthyl)ethyl]phosphine oxide in a total yield of up to 40%. Selective conditions for preparing the tertiary phosphine oxide from white phosphorus and 2-vinylnaphthalene in 58% yield were found. Phosphine and (2-phenylpropyl)phosphine add to 2-vinylnaphthalene in the KOH-DMSO system to form, under certain conditions, corresponding secondary phosphines in high yields.     

增强多孔纳米红磷的光氧化和光还原性能

通过水热法获得了多孔纳米结构的红磷,其中水热处理24 h所得的红磷(H-RP24h)具有最高的光催化活性,光氧化罗丹明B(RhB)和光还原Cr(Ⅵ)的速率常数分别是9.2×10^-2和3.4×10^-2 min^-1,是商业红磷的23和26倍。进一步研究发现水热处理减小了红磷的尺寸、增强了光响应、提高了光生电子和空穴(h^+)的分离,从而提高了它的光催化活性。通过自由基捕获实验发现在光降解反应过程中起主要作用的活性物种是h+和超氧自由基。     

红磷中磷化氢的缓释研究

利用顶空气相色谱法和加速老化技术研究了工业红磷中微量杂质对磷化氢产生的影响以及减慢磷化氢产生的方法。混入抑制剂可以减慢磷化氢的释放速度,加入纳米氢氧化镁可大大减慢磷化氢的生成速度小于而使之04mg/(m3·d),而且红磷的分散性和流动性很好。     

红磷/石墨复合材料的制备及电化学性能

研究了一种先通过机械球磨和水热法制得的亚微米红磷,再通过球磨亚微米红磷与石墨得到的块状亚微米红磷/石墨复合材料(smRP/G),并利用扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线光电子能谱分析(XPS)、循环伏安法(CV)等手段其进行了表征。 相对比普通红磷,亚微米红磷更容易通过球磨与石墨复合,能有效提升石墨材料的储锂容量。 为红磷在锂离子电池负极材料上的应用提供了一种思路。 在少量添加红磷的条件下,当红磷质量分数为3%时smRP/G表现最佳(3%smRP/G)。 在100 mA/g电流密度下展示出了1417 mA·h/g的首次放电容量,首次库伦效率67.4%。 并在循环200圈后依然保持着700 mA·h/g的可逆循环容量。     

Reaction of Activated Red Phosphorus with Phenylacetylene in the KOH-HMPA System

Russian Journal of General Chemistry -     

二元醇改性密胺甲醛树脂包覆红磷

用乙二醇和1,4-丁二醇对密胺甲醛树脂(MF)包覆红磷(MFRP)进行了化学改性,并对改性前后MFRP的磷化氢释放情况进行了比较。 在模拟材料加工条件下,纯红磷(RP)的磷化氢释放量为44.51 mg/L,MFRP磷化氢释放量降低到24.13 mg/L,而二元醇改性包覆红磷,磷化氢释放量降低到8.05 mg/L。 改性包覆效果显著。 用傅里叶红外光谱(FTIR)表征改性前后MFRP的结构,证实改性剂成功介入树脂结构中。 热重分析(TG/DTG)结果表明,改性后,MFRP的初始分解温度由未改性的264 ℃降到182 ℃,最大失重速率由11%/min下降到4.1%/min,800 ℃时,改性前后的MFRP残留量相同,均为11%。     

密胺树脂/硼酸锌双层包覆微胶囊化红磷的制备及其在阻燃聚烯烃中的应用

描述了采用密胺树脂和硼酸锌连续双层包覆微胶囊化红磷(MRP)的最新制备方法。采用红外光谱、电子能谱和透射电镜等分析手段对其进行了表征，并证实红磷已被完全包覆。实验数据表明：经包覆的MRP的热稳定性获得了明显改善，吸水率和磷化氢的发生量均大大减少。MRP作为阻燃助剂应用于聚烯烃阻燃材料表现出了良好的阻燃效果。实时红外和热失重测量以及扫描电镜观察表明：其阻燃机制是红磷受热时与树脂反应促进了含磷膨胀炭层的形成，从而提高了材料的热稳定性，碳层起到了隔氧、隔热作用，而且主要在凝聚相中发挥其阻燃作用。     

Facile Conversion of Red Phosphorus into Soluble Polyphosphide Anions by Reaction with Potassium Ethoxide

Soluble polyphosphide anions were successfully generated in a number of organic solvents by the reaction between shelf‐stable red phosphorus and potassium ethoxide. The species were identified by ³¹P NMR spectroscopy in solution and by X‐ray crystal‐structure determination of (Bu₄N)₂P₁₆ in the solid state. The reaction was scaled up to gram quantities by using a flow‐chemistry process.     

微胶囊化超细红磷的制备及其安定性研究

研究了用硝酸铝溶胶凝胶法制备微胶囊化超细红磷的工艺，通过着火点测试研究了包覆材料和包覆工艺以及影响包覆效果的因素，发现以5%氢氧化铝溶胶凝胶制备微胶囊化红磷在150 ℃左右真空干燥得到的样品安定性较好，XPS表明有95.3%的红磷被包覆，透射电镜显示形成一层均匀的包覆层，超细红磷的安定性得到了较大的提高。     

Reaction of Vinylpyridines with Active Modifications of Elemental Phosphorus in KOH/DMSO

The phosphorylation of 2-vinyl- and 4-vinylpyridines by white phosphorus and active modifications of red phosphorus (obtained by thermal polymerization of white phosphorus in the presence of graphite or the action of ionizing radiation in benzene) in the KOH/DMSO superbase system at room temperature leads to the formation of tris[2-(2-pyridyl)ethyl]- and tris[2-(4-pyridyl)ethyl]phosphine oxides in 58-72% yield. These oxides are promising ligands for design of metal complex catalysts. These vinylpyridines react less efficiently with ordinary red phosphorus and the yield of the corresponding tris(2-pyridylethyl)phosphine oxides does not exceed 10%.     

A Study of the Reaction of Phosphorus Trichloride with Paraformaldehyde in the Presence of Carboxylic Acids

Abstract

We investigated the mechanism of the reaction of paraformaldehyde with phosphorus trichloride in the presence of carboxylic acids (acetic, propanoic, and formic). Our results revealed that bisphosphonic acids were obtained without the use of water. The structures of the reaction products were studied by 1D and 2D homonuclear and heteronuclear ¹H-, ¹³C-, ³¹P- NMR spectroscopy.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional tables.]     

镧对红壤硝化、磷转化和酚分解作用的影响

通过室内培养和盆栽试验研究了La对红壤硝化作用,磷转化作用和酚分解作用的影响,低浓度下,La对土壤的硝化作用和磷转化作用均有某些刺激作用,但随着浓度的升高产生抑制作用并不断增加,La对土壤酚分解作用表现为剧烈的抑制作用,并随着浓度的升高,抑制作用不断增强,随着培养时间的延长,La对土壤硝化作用和酚分解作用的抑制作用有降低的趋势。     

物理技术辅助的Knoevenagel反应*

Knoevenagel反应的副产物是水,微波、超声波、研磨等物理技术辅助的有机合成方法高效、节能、环保,使物理技术辅助的Knoevenagel反应非常符合绿色化学的要求。目前,Knoevenagel反应被广泛应用于有机合成中,各种物理辅助合成技术的涌现对于提高其产率、简化其操作、扩大其应用范围具有日益重要的作用。同时,利用研磨新技术进行Knoevenagel反应的工业化探索也开始引人注目。本文按微波、超声波、研磨等物理辅助技术的不同,综述了近年来Knoevenagel反应研究的新进展,特别是涉及多组分反应、串联反应的Knoevenagel反应在多杂环化合物合成中的新应用。为了使Knoevenagel反应更加绿色化,可以预见在未来的Knoevenagel反应研究中,基于上述物理技术的利用Knoevenagel反应的合成方法学研究与Knoevenagel反应的工业化研究值得重视。     

A Thermogravimetric Study of Cotton Fabric Flame‐Retardancy by Means of Impregnation with Red Phosphorus

The effect of red phosphorus was found to be effective for flame‐retardancy of a pure cotton fabric. The laundered bone‐dried weighed samples were impregnated with red phosphorus at suitable concentrations. Vertical flame spread test was accomplished. The optimum add‐on value to impart flame‐retardancy onto cotton fabric was determined around 3.95 g of red phosphorus per 100 g of fabric. TG/DTG curves of treated samples showed a well‐timed weight loss occurred with regard to untreated specimens. This illustrates the sufficiency of impregnation and support its catalytic action on flame‐retardancy, which is compliance with data obtained via flammability test. The results are in favor of "Chemical Action Theory", "Gas Theory" and "Condensed Phase Retardation".     

微波辐射下4,6-二羟基嘧啶与醛的反应研究

以甲胺为催化剂、醋酸为溶剂, 微波促进下芳香醛与两分子4,6-二羟基嘧啶反应得到6-羟基-5-[(4-羟基-6-氧代-1,6-二氢嘧啶-5-基)芳甲基]嘧啶-4(3H)-酮衍生物.     

甲酚红分光光度法测定替米沙坦的含量

在pH为6.60的B-R缓冲介质中,替米沙坦(TMST)与甲酚红反应生成离子缔合物。当以试剂空白作参比时,在572nm及428nm波长处分别有正、负吸收峰。测定在572nm处增色反应的吸光度或在428nm处褪色反应的吸光度均与TMST的浓度之间呈线性关系,可作为测定TMST的基础。在所提出的方法中采用572nm作为测定TMST的检测波长。在此条件下TMST的浓度在4.6×10-7～1.3×10-5 mol.L-1之间与所测吸光度呈线性关系,其表观摩尔吸光率为5.34×104L.mol-1.cm-1。应用此方法测定了TMST胶囊和片剂中TMST的含量,测定结果与标示量相符,测定值的相对标准偏差(n=11)均小于2.5%。