Determination of bromide and nitrite by indirect redox titration using phenyl iodosoacetate

Bromide has been determined by its oxidation with an excess of phenyl iodosoacetate in the presence of acetanilide to give bromine which subsequently reacts with acetanilide to form 4-bromoacetanilide. The residual amount of phenyl iodosoacetate was evaluated iodometrically. Thus, for every mol of bromide one mol of phenyl iodosoacetate was consumed. For the determination of bromine in organic compounds, the test substance was decomposed by fusion with alkali peroxide to liberate bromide which was then evaluated by the phenyl iodosoacetate method. For its determination, nitrite has been reacted with an excess of isoniazid in acid medium to form isonicotinyl azide (which does not react with phenyl iodosoacetate) and the residual amount of isoniazid was titrated with phenyl iodosoacetate in the presence of acidified bromide and methyl red indicator (when isoniazid and phenyl iodosoacetate react in a 12 molar ratio). Each mol of nitrite is equivalent to 2 mol of phenyl iodosoacetate.     

Catalytic reduction of aromatic polynitro compounds

The liquid-phase catalytic hydrogenation of 3,5-dinitrophenyl phenyl ether to give 3,5-diaminophenyl phenyl ether in the presence of Group VIII metals as catalysts has been investigated. The main kinetic characteristics of the process have been established. The reduction occursvia the formation of 5-amino-3-nitrophenyl phenyl ether. In terms of their activity, the catalysts studied can be arranged in the following sequence: 1% Pd/Sibunit> 2 % Pd/C > Lindlare Pd > 5% Ru/Sibunit > Raney Ni. The selectivity of the process with respect to intermediate 5-amino-3-nitrophenyl phenyl ether depends on the relative adsorption abilities of mono- and dinitro compounds. A promoting effect of water during hydrogenation of 3,5-dinitrophenyl phenyl ether in isopropanol or 1,4-dioxane has been noted. Catalytic synthesis of 3,5-diaminophenyl phenyl ether has been carried out for the first time.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1716–1719, September, 1995.     

NiCl2bpy催化卤代苯的电化学偶联及其机理研究

Electrochemical coupling of phenyl halide catalyzed by NiCl_2bpy in DMF has been investigated in this paper.Stainless steel was used as cathode and zinc as anode.Effects of potential,temperature and catalyst on electrolyseswere studied to optimize the electrolytic conditions,with the maximal isolated yield under potentiostatic electrolysisto be 85%.Cyclic voltammetry of NiCl_2bpy in the presence of phenyl bromide has been studied and mechanisms,concerned with several kinds of nickel complex,have been summarized.     

Proximity effects in the electron impact mass spectra of aurones and related compounds

The principal ions in the electron impact mass spectra of a series of 6-methoxyaurones have been shown to be due to four separate reactions associated with proximity effects involving the phenyl group and the coumaran-one residue. A detailed study with labelled derivatives has been supplemented by a study of the vinylogue 2-cinnamylidene-6-methoxycoumaran-3-one and compounds in which the aurone phenyl group has been replaced by α-naphthyl, β-naphthyl and 9-anthryl.     

S′H type reactions of substituted allylic compounds

S′_H reactions of allyl sulfides and halides with phenyl radicals are reported. Thermal decomposition of phenylazotriphenylmethane with allyl sulfides and bromide has been shown to give allylbenzene. This apparent substitution reaction involves attack of a phenyl radical on the terminal unsaturated carbon atom of the allyl sulfide; the reaction in α,α-dimethylallyl ethyl sulfide produced 2-methyl-4-phenylbutene-2. To estimate the relative reactivities of allylic substrates towards phenyl radicals, competitive reactions of phenyl radicals with allylic compounds and carbon tetrachloride were investigated. The data indicate that the radical formed by addition of a phenyl radical to the allylic sulfide looses thiyl radicals almost quantitatively.     

Anion-dependent self-assembly of silver(I) and diaminotriazines to coordination polymers: non-covalent bonds and role interchange between silver and hydrogen bonds

New coordination polymers have been obtained by the self-assembly of silver salts AgX (X = BF 4, PF 6, CF 3SO 3) and 2,4-diamino-6-R-1,3,5-triazines L (R = phenyl and p-tolyl) of formulas AgLX ( 1- 6). A complex of different stoichiometry, [Ag 3L 2(H 2O)(acetone) 2](BF 4) 3, 7 (R = phenyl), has also been synthesized. The three-dimensional structures of five compounds have been determined by X-ray diffraction studies. For the AgLX complexes, when X = BF 4 and R = phenyl or p-tolyl, chiral chains with alternating Ag and L are formed. The chains are cross-linked by the counteranions in a three-dimensional fashion through hydrogen bonds and weak Ag...F interactions giving rise to a structure with solvent-filled channels. Different and more compact structures have been found when the counteranion is CF 3SO 3 (OTf). When R = phenyl, sheets are formed which consist of [Ag 2(OTf) 2L 2] units with double triflate bridges and which contain columns of pi-pi stacked arenes. Hydrogen bonds connect the sheets. When AgOTf is used and R is p-tolyl, a different and unusual ladderlike structure is obtained in which the rungs are double asymmetric bridges consisting of the triflate groups bonded to Ag in kappa (2) O,mu 2- O and kappa (1) O,mu 2- O fashion. The ladders are parallel to each other and are mutually linked by N-H...N hydrogen bonds to give a 3D architecture. A very similar ladderlike structure has been found for 7 but with a water molecule and a BF 4 (-) group acting as bridges. The role played by the hydrogen bonds in complex 6 to form the 3-D structure is played in 7 by [Ag(acetone) 2] fragments. The noncovalent interactions play an important role in the different solid-state 3D structures. The behavior of the new derivatives in solution has also been analyzed. A new species has been detected at low temperatures, and this exhibits restricted rotation of the phenyl ring.     

Study on retention behavior of cyclic siloxanes by high resolution pyrolysis-gas chromatography with a fused silica capillary column

The general gas chromatographic retention behavior of cyclic methylsiloxanes partially substituted with phenyl or 2-cyanoethyl groups has been systematically studied, with pyrolysis-gas chromatography being utilized to form the cyclic siloxanes from the corresponding polysiloxanes at a temperature of 600°C. Kovats retention indices (KI) were determined for the cyclic siloxanes by use of the retention data of the pyrolyzates from polyethylene as standards. The effect of phenyl and 2-cyanoethyl substituents in the cyclic siloxanes on retention behavior has also been considered.     

Photochemistry and photophysics of a morpholino methylthio phenyl ketone: A steady-state, picosecond pump-probe laser spectroscopy and molecular modeling investigation

The photophysics of 2-methyl-1-[4-(methylthio) phenyl]-2-(4-morpholinyl)-1-propanone TPMK, compared to that of two reference compounds (2-methyl-1-phenyl-2-(4-morpholinyl)-1-propanone and 1-[4-(methylthio)phenyl]-ethanone), was studied by means of absorption spectroscopy, phosphorescence and time-resolved absorption spectroscopy. A four-level kinetic scheme has been proposed for TPMK as an explanation for the observed excited state processes. A strong solvent effect has been noticed upon the excited state lifetimes. Modeling calculations help to describe the excited state properties.     

2,5-二取代噁唑的研究(Ⅵ)-2-联苯基-5-苯基噁唑和其5-对位取代苯基衍生物光谱的溶剂效应

本文报导了14种2-联苯基-5苯基噁唑和其5-对位取代苯基衍生物在环己烷、无水乙醇和1,4-二氧六环三种溶剂中测得的紫外吸收光谱和荧光发射光谱。并从21种溶剂的宏观物理性质(n,ε),Z值、E_T值和取代基常数σ_p三个方面研究2-联苯基-5-对乙苯基噁唑光谱的溶剂效应。     

The effect of the hydrogen bonds on the molecule conformation in 2-biphenylmethanol

Infrared spectra of hydrogen-bonded organic compound 2-biphenylmethanol has been studied in the wide temperature range from 320 to 12 K. It has been found that IR spectra drastically changed with temperature in the 700–850, 1290–1500, and 3100–3600 cm⁻¹ spectral regions, where deformational vibrations of phenyl rings and methanol group, as well as ν(OH) stretching vibration manifest themselves. The analysis of the computer simulation of the IR spectra for various 2-biphenylmethanol conformers, which are characterized by different combinations of angles of the mutual orientation of the phenyl rings relative to each other and a methanol group relative to the phenyl ring allowed us to conclude that the hydrogen bonding results not only in the shortened of the intermolecular bonds, but also in the increasing of the angle between phenyl ring and methanol group. In other words, hydrogen bonding leads to the changes in the molecule conformation.     

The formation of Pt(P–P)(X)(COAr) (X=Cl, I; Ar=Ph, 2-Tioph) complexes via insertion of carbon monoxide

Pt(diphosphine)X(aryl) complexes [diphosphine = 1,3-bis(diphenylphosphino)propane (dppp); aryl=phenyl, 2-thiophenyl; X=Cl, I] have been reacted with carbon monoxide in chloroform. It has been revealed by in situ NMR studies that the starting compounds insert carbon monoxide into the Pt-aryl group resulting in Pt(diphosphine)X{C(O)aryl} complexes. It has been found that the phenyl complexes are much more reactive than the corresponding 2-thiophenyl complexes. Similarly, higher reactivity has been observed with iodo than with the chloro complexes.     

Synthesis of 3‐(2‐benzyloxy‐6‐hydroxyphenyl)‐1‐methylpyrazoles by the reaction of chromones with methylhydrazine

The 3‐(2‐benzyloxy‐6‐hydroxyphenyl)‐5‐(methyl, phenyl or styryl)pyrazoles were prepared from the reaction of 2‐(methyl, phenyl or styryl)chromones with methylhydrazine. The structure of these compounds has been determined by several nmr techniques, and the reaction mechanism is discussed.     

Mercuration of thiazole derivatives

Conditions have been found for the mercuration of alkyl- and aryl- thiazoles. Mercuration takes place in position 5 of the ring, if it is free, and does not depend on the nature of the substituent in position 2. The possibility of the mercuration of a trisubstituted thiazole has been shown for the first time. When a phenyl radical is present in position 2, the mercury ion enters the para position of the phenyl nucleus.     

Alkatrienyl Sulfoxides and Sulfones. Part I. 3-Methyl-1,2,4-pentatrienyl Phenyl Sulfoxide-Synthesis and Electrophile-Induced Cyclization Reactions

A method for the synthesis of the 3-methyl-1,2,4-pentatrienyl phenyl sulfoxide 3 by [2,3]-sigmatropic rearrangement of the 3-methyl-1-penten-4-yn-3-yl benzenesulfenate 2 , formed in the reaction of the 3-methyl-1-pentene-4-yn-2-ol 1 with phenylsulfenyl chloride has been created. Possibilities and restrictions of the five-membered heterocyclization in electrophile-induced reactions leading to the synthesis of the 5H-1,2-oxathiol-2-ium salts 5 , 7 , and 8 have been explored. Chlorination of the sulfoxide 2 proceeded with formation of the (E)-2-chloro-3-methylene-1,4-pentadienyl phenyl sulfoxide 4 , while the bromination afforded the 4-bromo-5H-1,2-oxathiol-2-ium bromide 5 , which after reflux in 1,2-dichloroethane eliminated hydrogen bromide and was transformed into the (E)-2-bromo-3-methylene-1,4-pentadienyl phenyl sulfoxide 6 .     

氯苄双羰化合成苯丙酮酸新型催化剂吡啶-2-羧酸钴 研究

实验发现吡啶-2-羧酸钴是氯苄双羰化合成苯丙酮的新颖催化剂。在水和1,4-二氧六环混合溶剂中,当T=353K,p=2.4mPa,V(H2O):V(dioxane)=1:1.1,氧化钙与氯苄克分子比为1.00,氯苄与吡啶-2-羰酸钴的摩尔比为1:0.05时,氯苄转化率为74.5%,选择性达99%,苯丙酮酸产率为73.8%。研究了反应条件对苯丙酮酸产率和选择性的影响,并使用IR,UV,GC-MS等对产物进行了测定。     

The synthesis of oximes containing the ferroin group

A series of oximes of substituted 2-pyridylmethyl and phenyl ketones has been prepared. These all contain the ferroin group (?N? C? C? N?). The 4-substituted pyridyl-syn-methyl and phenyl ketoximes form chelates with Fe(II).     

Theoretical and experimental ionization potentials of (CH3)2S and (CH3)2SO. The effect of substituents R on the sulphur ESCA shifts in the series R2S, R2SO, R2SO2

Theoretical and experimental inner shell ionization potentials (IP) have been determined for (CH₃)₂S and (CH₃) ₂SO. This information is combined with other data to draw conclusions on the effect of methyl and phenyl substituents in the series R₂S, R₂SO and R₂SO₂, on the chemical shifts of the sulphur ²P IP. It was found that while methyl substitution has no significant effect on the chemical shifts of the sulphur ²P IP, phenyl substition modifies them significantly implying a donation of electron density from the phenyl groups to sulphur.     

对位取代二苯乙烯衍生物的合成和非线性光学性质

合成了反式-4-[N-（乙氧基羰基-4"-硝基苯基）-N'-乙基氨基]-4'-(二甲基氨 基)二苯乙烯(DMANHAS)和三个新有机化合物。用核磁、红外以及元素分析进行了表 征。测试了紫外吸收光谱、单光子荧光光谱和双光子荧光光谱。在800nm的飞秒脉 冲激光激发下,反式-4-（N-羟乙基-N'-乙基氨基）-4'-(二甲基氨基)二苯乙烯 (DMAHAS)和反式-4-(N-羟乙基-N'-乙基氨基)-4'-(二乙基氨基)二苯乙烯(DEAHAS) 均发出较强的蓝紫色上转换荧光,荧光峰分别位于436和440nm,而DMANHAS和反式- 4-[N-(乙氧基羰基-4"-硝基苯基)-N'-乙基氨基]-4'-（二乙基氨基）二苯乙烯 (DEANHAS)没有荧光。     

Kristallstruktur und Stereochemie von [2-(Diorganophosphinyl)phenyl]-dimethylzinnchloriden

Crystal Structure and Stereochemistry of [2-(Diorganophosphinyl)phenyl]-dimethyltin Chlorides The crystal structure of [2-(Diphenylphosphinyl)phenyl]-dimethyltin chloride (1) has been determined and refined to an R value of 0.038. The configuration around the tin atom corresponds to a distorted trigonal bipyramid with an intramolecular distance Sn…0 of 235.7(9) pm. The planar arrangement of the five-membered chelate ring represents the transition between two envelope conformations. Temperature and solvent dependent NMR measurements confirm for [2-(t-Butylphenylphosphinyl)phenyl]-dimethyltin chloride (2) a stable configuration of the ligand polyhedron at the tin atom within the NMR time scale.     

Hydrogen/deuterium exchange in gas phase reactions of anions with some alkyl phenyl ethers

The gas phase reactions of anions with methyl and ethyl phenyl ether have been studied by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. ¹⁸O-Labelling has shown that part of the reactions of OH^- with methyl phenyl ether proceed via ipso-substitution, the main reaction channel being S_N2 substitution. Deuterium labelling has shown that extensive inter- and intramolecular hydrogen/deuterium exchange can precede the final substitution reaction. Hydrogen atoms originating from the methoxy substituent are involved in this exchange process. The reactions of anions with ethyl phenyl ether proceed mainly via an elimination mechanism. Deuterium labelling has shown that in some cases hydrogen/deuterium exchange takes place prior to elimination.