The Suprising Variety of Products from Reactions of P-P Bonds with Dichlorogermylene

Abstract

Insertion of dichlorogermylene (from GcCl₂-dioxane) into the P-P bonds of tetraalkyldiphosphanes ((PRR)₂ (2a: R, R ? i-Pr; 2b: R? t-Bu, R?i-Pr; 2C; R, R, ?t-Bu) leads 10 dichlorobis(dialkylphosphanyl)germanes 3a-c. With 2a. the insertion remains incomplete: 38 exists in an equilibrium with an adduct of diphosphane 2a with GeCI₂, Subsequently 3b and 3c undergo a-climinarions to dialkylchlorophosphanes Sb and Sc and the dimeric phosphanylgermylenes (RR PGeGl)² 4b and 4c [1]. Similar to the above (but in absence of dioxane), reacting the richlorogcrmylphosphane i-Pr(t-Bu)PGeCL₃, 7c [2] with the related trichlorosilylphosphanc i-Pr(t-Bu)PSiCl₃ provided a mixture of SiCl₄, 1c, 3c, 5c and 7c, 3a and 3c have been trapped as inert molybdenum complexes (CO)₄ MO(μ-PRR)₂ GeGl₂ 6a and 6c from cquilibrilia conraining la/ 2a/ 3a and 3c/ 4c / 5c / 7c respectively.     

Reactivity of Conjugate Bases of Hydridophosphoranes. Synthesis of New Phosphoranes Involving P-P Bonds

Abstract

Hydridophosphoranes 1, 2 react, in presence of triethylamine, with phenyldichlorophosphine, diphenylchlorophosphine and the chlorophosphorane 3 giving unusual phosphoranes bearing P-P bonds. These last have been isolated and their structure has been determined by NMR spectroscopy.     

Reaction of 4-Nitrobenzenesulfenamide with Liquid Ammonia

Abstract

Although numerous investigations on the chemistry of organic sulfenamides, for example, studies on the S–N torsional barrier,¹ the electronic nature of the S–N bond² and some nucleophilic substitutions on sulfur or nitrogen atom³ have been known, no example of nucleophilic substitution on arylcarbon of aromatic sulfenamides has been reported.     

Metallo Dioxaphospholanes with Metal to Phosphorus Single and Double Bonds

Abstract

Metallo dioxaphospholanes Cp(CO)₃M-POCMe₂CMe₂O (M=Cr, Mo, W) 1, which contain the σ-bound metal ligand in a pseudo axial position at the pyramidally configurated phosphorus, are obtained by a nucleophilic metallation of 1-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane with the anions Na[M(CO)₃Cp] (M=Cr, Mo, W). 1 (M=W) is highly reactive towards quaternisation with MeI and oxidation with elementary sulfur, which reactions yield [Cp(CO)₃W-P(Me)OCMe₂CMe₂O]I 2 and Cp(CO)₃W-P(S)OCMe₂CMe₂O 3, respectively. Exchange of CO against P(OMe)₃ affords Cp(CO)₂[P(OMe)₃]W-POCMe₂CMe₂O 4, which rapidly rearranges to Cp(CO)₂-[P(O)(OMe)₂]W-P(Me)OCMe₂CMe₂O 5 via an O-P methyl group shift.     

Nature of Bridging Bonds in Lithium and Potassium Acetate Dimers

The structures of lithium and potassium acetates were studied by the RHF/6-31G** quantum-chemical method. The metal-oxygen bonds in the dimers (CH₃COOLi)₂ and (CH₃COOK)₂ are electrostatic in nature. The bridging lithium bond is intermediate between hydrogen and ionic, and its peculiarity is determined by the deformation of molecular orbitals in the field of the lithium cation. The resulting data allow the variety of glassy smectic mesophases of lithium acetate.     

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

Russian Journal of General Chemistry -     

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:     

Reaction of Red Phosphorus with Allylbenzene in Superbasic System KOH-DMSO

Abstract

Red phosphorus reacts with allylbenzene in the superbase system KOH-DMSO (130°C, 3 h, Ar) to give a mixture of bis(1-methyl-2-phenylethyl)phosphane (1), bis(1-methyl-2-phenylethyl)phosphane oxide (2), and 1-methyl-2-phenylethylphosphinic acid (3). Secondary phosphane oxide 2 and phosphinic acid 3 have been isolated from this mixture in 35% and 32% yield, respectively. Microwave activation of the reaction (200 W, 30 min) affords secondary phosphane 1 as the main product in 48% yield.

GRAPHICAL ABSTRACT      

The Behavior of Sulfur in Liquid Ammonia

Abstract

Spectrophotometric observations, electrochemical data, esr spectrum and cryoscopic measurements in solutions of sulfur in liquid ammonia are reported. They indicate that the sulfur species present at low temperatures is S₂NH₃. At room temperature the predominant species is SNH₃.     

锂在共轭双键高分子中的电化学嵌入反应Ⅲ.锂在聚萘中的电化学嵌入反应

研究了锂在导电高聚物--聚萘中的嵌入反应.聚萘样品经650℃处理,作为锂电池的正极,组装成Li/(C10H6)n电池.X射线衍射分析、ESR实验、X射线光电子能谱分析等一系列实验证实上述电池的正极反应是锂在聚萘中的电化学嵌入反应.通过XRS实验对嵌入聚萘的锂进行了价态分析,认为嵌进去的锂是以原子态及离子态两种状态存在,其结合能分别为55.7eV和57.4eV.采用电化学暂态测量技术研究了锂在导电高聚物--聚萘中的扩散,计算了锂在嵌合物中的离子电导率及淌度.用Hebb-Wagner直流极化法测量了嵌合物的电子电导.     

Reaction of Hypoxanthine and Its Analogs with Acrylonitrile in Liquid Ammonia

Russian Journal of General Chemistry -     

Kinetic Isotope Effects in Hydrogen Exchange of Aromatic CH Bonds in Benzene,Fluorobenzene, and Nitrogen-containing Heterocycles with Solution of Alkali Metal Amide in Liquid Ammonia

The kinetic isotope effects in deuterium and tritium exchange in benzene, fluorobenzene, pyridine, pyridine N-oxide, and quinoline with a solution of an alkali metal amide in liquid ammonia k _DNH₃/k _TNH₃ were determined, where k _DNH₃ and k _TNH₃ are the experimental rate constants of protodedeuteration and protodetritiation, respectively. The variation of the tritium exchange rates in benzene in going from NH₃ to ND₃ (k _TNH₃ and k _TND₃) was evaluated. The deviation of the observed ratios k _DNH₃/k _TNH₃ and k _HND₃/k _TND₃ from the maximum possible values corresponding to the Swan-Shaad equation suggests the reaction mechanism in which both elementary stages, ionization of the CH acid and diffusion separation of the complex of the carbanion with the ammonia molecule, are partially limiting. A small decrease in the secondary isotope effect of the solvent, defined as k _TND₃/k _TNH₃, as compared to the theoretical maximum of 2.4, is assumed to be due to similar structures of the transition state and the equilibrium carbanion. A theoretical explanation was given for the observed dependences of the primary isotope effect of the substrate on pK _a for deutero (tritio) derivatives of fluorobenzene [4D(t) < 3D(t) < 2D(t)], for reactions in the series pyridine-2D(t) < pyridine-3D(t) < quinoline3D(t), and for hydrogen exchange in pyridine-2D(t) N-oxide (k _DNH₃/k _TNH₃ 1).     

端基含双键的液晶单体的合成

以对羟基苯甲酸甲酯为起始原料,通过醚化和酯化反应合成了系列端基为双键的液晶化合物（d_nm）,其结构经¹H NMR, ¹³C NMR, FT-IR和元素分析表征。并采用差热扫描量热仪（DSC）和热台偏光显微镜（POM）研究了其液晶性能。结果表明：目标化合物均为互变性热致向列相液晶单体,且其熔点和液晶相转变温度随烷基碳数（m）增加先增大后减小。     

Electrochemical Behavior of Azo Compounds in Liquid Ammonia

Abstract

At -40°C, the behavior of lO compounds, differing widely in their standard potentials, has been investigated in liquid ammonia, using cyclic voltammetry at a smooth platinum electrode. The purpose of this study was the realization of a redox scale with reversible systems. With azobenzene, pyridazine, cin-noline, benzocinnoline and 4,4′-azobis-(pyridine-N-oxide), the first electron transfer is reversible and leads to the formation of the corresponding radical anions which are stable; the second electron transferleads to the ciianions which can be protonated yielding the corresponding hydrazo. Other compounds, such as azoxybenzene, 3-amino-1,2,4-triazine, pyridine-N-oxide, 8-azaadenine and 1H-tetrazole, have an electrochemical behavior which i s more intricate.     

The reaction of N-Acyl imines with t-Butyl isocyanide

N-Acylimines and their derivatives react with t-butyl isocyanide only the in presence of acid catalysis. The major products of these; reactions are 5-aminooxazoles and 5-iminooxazolines. The structure of these compounds and some of their degradative chemistry is discussed.     

Crystal Structure of a Novel Phosphorane (C30H27N3O12P4)with Three P-P Bonds

1　INTRODUCTIONInrecentyears,therehasbeenmuchinterestinphosphoranescontainingonlyonephosphorus-phosphorusbondandthestructuresofmostofthesecompoundshavebeenidentifiedbyX-raycrystallography[1～6].In1990,anewtypeofphosphoraneinvolvingtwoP-Pbondswassuccessfullysynthesized[7],butthecrystalstructurewasnotdetermined.Wehavesuccessfullysynthesizedthenovelphosphorane3bear-ingthreeP-Pbonds.Hereitscrystalstructureisreported.2　EXPERIMENTAL2.1　PreparationAllprocedureswereperformedunderN2atmos…     

具有分子间氢键的刚性长侧链液晶高分子的合成

主链液晶高分子材料力学性能的各向异性,限制了其作为结构材料的应用和发展^[1].含马来酸酐共聚物(如与乙烯、异丁烯、十八碳烯、苯乙烯和氯乙烯等交替、无规结构共聚物,其中马来酸酐质量分数为5%～50%)是一种耐热性和加工性优良的树脂.