Chlorine Dioxide as an Electron-Transfer Oxidant of Olefins. Preliminary Communication

The kinetics and product studies of oxidation of eight olefins 1 - 8 by ClO₂ in H₂O in the pH range 3-7 are described. The reaction is faster as the pH decreases. At pH < 4, ClO₂ reacts equimolarly with olefins to yield isomeric mixtures of chlorohydrines and 1,2-dioxygenated products, following the equation: The order of reactivity is: (E)-stilbene > indene > β-methylstyrene > acenaphthylene > α-methylstyrene > styrene > cyclohexene > allylbenzene. A multi-stage radical-cation mechanism is proposed, in which an initial reversible protonation: is followed by an electron-transfer stage (rate-determining): The cation-radical thus produced, adds rapidly an additional ClO₂ to form dioxygenated products. The chlorohydrines most likely arise from HClO additions to the olefinic double bonds, which, in turn, generate from dismutation of 2 HClO₂ into HClO + H⁺ + ClO.     

Zur Darstellung von Cyclophosphaten,Cyclophosphatophosphonaten, Diphosphonaten und Diphosphiten in Harnstoffschmelzen

Preparation of Cyclophosphates, Cyclophosphatophosphonates, Diphosphonates, and Di-phosphites in Urea Melts Ammonium cyclotriphosphate (NH₄)P₃O₉, ammonium cyclotetraphosphate [P^IV? P^IV ? O? ]₂, ammonium cyclotriphosphatophosphonates Ammonium organyldiphosphonates And ammonium diphosphites are prepared in high yields on heating acidic phosphates, phosphonates, and phosphites in urea or urea/ammonium nitrate melts. The mechanism of the dehydration of phosphorus compounds containing POH groups in molten urea is discussed.     

The pyrolyses of tri- and tetramethylethylene in the presence of nitric oxide

The pyrolyses of trimethylethylene and tetramethylethylene have been investigated in the presence and absence of nitric oxide. It appears that apart from a unimolecular split, e.g., a disproportionation reaction such as may play an important role in initiation. Nitric oxide had no effect on H₂ production, which is probably a molecular process. There was similar behavior of both compounds in the presence of NO, indicating that the olefinic hydrogen atom does not play a decisive role. Other aspects of the mechanisms are discussed.     

Structural changes in polymers of diethyl succinylsuccinate(1,4-diethoxycarbonyl-2,5-dihydroxy-1,4-cyclohexadiene) with diamines at high temperatures

The structural changes of the polymers having the following structures: at high temperatures were studied by the spectroscopic and thermal analysis. When the polymers were heated in air, they were oxidized predominantly to polymers having the structure: The rate of oxidation was fast and the reaction was almost completed within 2 hr at 180°C. In the case of polymer 3, an intramolecular cyclization to form acridone was detected as a minor reaction.     

Some new examples of cationic polymerization

Synthesis and properties of cis-and trans-methoxyvinyl chloride (MVC) are described. Both of these monomers can be polymerized with cationic initiators. From the ¹³C-NMR spectra it was concluded, that poly-(trans-MVC) is mainly threo-diisotactic. Copolymerization of cis-MVC with for instance trans-MVC or styrene or 1,3-dioxolane is also described. The ring-opening polymerization of 2-phenyl-2-oxazoline under different conditions was investigated. The molecular weights, determined by light-scattering and GPC are in the range between 10 000 and 350 000. A[η] -M- equation was derived. By hydrolysis with hydrochlorid acid high molecular weight poly(iminoethylene) was obtained. The ring-opening polymerization of 1-azabicyclooctane [4.2.0] (conidine) with different catalysts as well as the properties of the polymers were studied in detail. By means of a “mixed-mechanism technique” well defined styrene-conidine diblock copolymers are available.     

Durch Nachbargruppenbeteiligung induzierte (1,2)-Chlorwasserstoff-Eliminierung aus ionisiertem 2-(β-Chloräthyl)- benzoesäuremethylester

By using deuterium labelled compounds and collisional activation spectra the mechanism of the unusually intensive HCl elimination from 2-(β-chloroalkyl)benzoic acid methyl ester as well as the structure of the product ion have been elucidated. It can be shown that the structure of the stable ion (lifetime τ～10?5 s) is best represented by 2-vinyl benzoic acid methyl ester whereas the reactive ion (lifetime τ<10^?6 s) at least partially rearranges to a cyclic ion. The hydrogen chloride elimination from 2-(β-chloroalkyl)benzoic acid is apparently a simple 1,2 process. A closer examination reveals that the reaction represents a further example of an unusual neighbouring group participation of the ester function.     

Interfaces between coexisting phases in polymer mixtures: What can we learn from Monte Carlo simulations?

Symmetric binary polymer mixtures are studied by Monte Carlo simulation of the bond fluctuation model, considering both interfaces between coexisting bulk phases and interfaces confined in thin films. It is found that the critical behavior of interfacial tension and width is compatible with that of the Ising model, as expected from the universality principle. In the strong segregation limit, only qualitative but not quantitative agreement with the self-consistent field (SCF) theory is found. It is argued that the SCF theory requires but for the short chains studied (N = 32 effective monomer units per chain), the limit is only reached for close to unity. Also, the effective χ-parameter decreases in the interface. It is shown that the interfacial width w does not increase by the adsorption of block copolymers as long as their areal density is still dilute (“mushroom” regime). But a broadening of interfaces does occur for thin films confined between walls at distance D, due to fluctuations that lead to for short-range forces, in agreement with experiment.     

Eine neue einfache Methode zur Entalkylierung von Phosphon- und Phosphinsäureestern

A New Facile Method for the Dealkylation of Phosphonic and Phosphinic Acid Esters The synthesis of phosphonic and phosphinic acid esters of the type is realized by reaction of dialkylphosphonates and O-alkylphosphinates with chlorotrimethylsilane in the presence of catalytical amounts of NH₄Cl and hexamethyldisilazane (HMDZ).     

Effects of molecular weight,rubber toughening,and environment on fatigue crack propagation behavior of block amide copolymers

The Fatigue Crack Propagation (FCP) behavior of block amide copolymers is investigated as a function of molecular weight, rubber toughening as well as environmental conditions. The enhancement of FCP resistance with increasing average molecular weight is shown and correlated to features observed on the fracture surface. Particular attention is paid to hysteretic heating, measured with an infrared camera, in the crack tip zone of different average molecular weight copolymers and rubber-toughened copolymer. A FCP approach of stress-cracking in an aqueous solution of zinc chloride is proposed here. An improvement in FCP resistance as the average molecular weight increases, similar to that exhibited in normal environment, appears. The shift in da/dN values over the tested range of can be approximated by an exponential function:      

Effect of gegen ion in cationic polymerization and copolymerization of trioxane

p-Chlorophenyldiazonium hexafluorophosphate has been reported to be a superior catalyst for cationic polymerization and copolymerization of trioxane as compared to boron trifluoride dibutyl etherate (BF₃·Bu₂O)¹. In the present investigation the effect of anions derived from elements in Group VA, AsF and SbF, has been ascertained. It has been concluded that p-chlorophenyldiazonium hexafluoroarsenate is also a superior catalyst to boron trifluoride dibutyletherate (BF₃·Bu₂O), while p-chlorophenyl-diazonium hexafluoroantimonate is inferior. Copolymers with the highest polymer yield (>95%) and molecular weight (intrinsic viscosity = 4 to 5) were obtained with Simple dependences on catalyst concentration have been observed to hold for a wide catalyst concentration range ([M]/[C]) = (1 to 20) × 10⁵: For the same relationships hold. However, the polymer yield (75%) and molecular weights (intrinsic viscosity ?1) are considerably lower while the extent of chain transfer is higher. Furthermore, the polymerization proceeds with explosive violence. The quantitative aspects resulting from polymerization, for the most part, can be interpreted in terms of the extent of dissociation of the propagating ions.     

Massenspektrometrische Untersuchung organischer Stickstoffverbindungen. XXVII—Intramolekulare Redoxreaktionn bei ionisierten ortho-substituierten Nitroaromaten

Collisional activation demonstrates that the stable ions from o-nitrobenzaldehydedimethylacetale possess the structure of ionized o-nitroso benzoic acid methyl ester. Contrary to previous conclusions it is demonstrated that the structure of the stable ions (m/e 135) from different precursors [i.e. o-nitrobenzyl alcohol o-nitrobenzyl cyanide and o-nitrobenzaldoxime is best represented by 2,1-benzisoxazoline-3-one. Ionized o-nitrosobenzaldehtde rearranged to 2,1-benzisoxazoline-3-one prior to collision induced decomposition, whereas 2-benzoxazolinone and 3-hydroxy-1,2-benzisoxazole do not rearrange within 10^?5 s.     

Structure of the tetramer of α-methylstyrene

The structure of the tetrameric dianion formed by α-methylstyrene in tetrahydrofuran by reaction with sodium has been examined. Mass spectral, NMR, infrared, and kinetic data all indicate that the structure is rather than the structure which had previously been assumed for this species.     

Living cationic polymerization of 2-chloroethyl vinyl ether: Kinetics,mechanism and application to polymer synthesis

The cationic polymerization of 2-chloroethyl vinyl ether initiated by HI/weak Lewis acid (I₂ or ZnI₂) systems has been studied from both a kinetic-mechanistic and a synthetic viewpoint. At low temperature and in toluene as solvent, the polymerization proceeds via a living process and the kinetic order with respect to monomer varies according to the nature of the Lewis acid activator. This behaviour can be explained by the coordination of the Lewis acid with both the monomer and the chain-end, the latter leading to a strong activation of the -I bond towards monomer insertion. The living polymerization obtained from divinylether precursors leads to -I ended telechelics, and their transformation into dihydroxytelechelic oligomers has been performed. The chemical modification of chloroalkyl side groups by phase transfer catalysis allows the attachment of specific groups without consumption of-OH ends.     

Synthesis and psychotropic properties of furyl- and thienyl-germatranes

Trihalogermyl-furans and -thiophenes were prepared by inserting germanium dibromide (GeBr₂) generated from the dibromogermane(II) dioxanate complex into the carbon-halogen bond of halo-furans and -thiophenes. Their ethanolysis and transesterification by triethanolamine yielded the germatranes which were subjected to psychotropic activity assays. The psychotropic properties of germatranes were found to depend on the type of the heterocycle and on the position of the germatrane moiety.     

Fluorsulfonylstickstoffverbindungen

The reactions of fluorosulfonylurea derivatives with phosphorus pentachloride in carbon tetrachloride leads to and . These compounds are easily fluroinated by arsenic trifluoride to the corresponding fluorosulfonyl derivatives. It was shown that PCl₅ is reliable for the fluorine-chlorine exchange. Isocyanate esterchlorides as well as carbonyl-fluoride derivatives react with compounds which have an active hydrogen atom. By this way were prepared: . By hydrolysis of , is probably formed as the first reaction product. The acid could be trapped with tetraphenylphosphoniumchloride as a well-cristalline salt. Fluorosulfonyl isocyanate reacts with aldehydes to the following compounds: FSO₂N ? CHCH₃, FSO₂N ? CHC₂H₅, FSO₂N ? CH? CH(CH₃)₂ and FSO₂N ? CHC₆H₅. The physical and chemical properties as well as IR and NMR spectra of the compounds are described and, in part, compared and discussed.     

Electron impact studies. CVII—Negative ion mass spectra of the oxime group. Monoximes derived from α-dicarbonyl systems

Specific losses of water are observed from the molecular anions of monoximes of α-diketones. Labelling studies, kinetic energy release values and the +E spectra of ions have been used to aid in the elucidation of the fragmentation pathways. It is proposed that the majority of ions have α-keto nitrile structures.     

HNO,an Intermediate in (Light-induced) Rearrangement Reactions of Nitrosooxy Compounds and Nitrosamines

IR-spectroscopic investigations of light-induced rearrangement reactions of nitrosooxymethane (CH³ONO³), nitrosooxyethane (CH₃CH₂ONO) and N,N-dimethylnitrosamine ((CH₃)₂NNO) in low-temperature rare-gas matrices have established that these molecules are transformed in two photolysis steps to the previously unknown C-nitroso compounds nitrosomethanol (CH₂(OH)(NO)), 1-nitrosoethanol (CH₃CH(OH)(NO)), and methyl(nitrosomethyl)amine CH₂(NO)(NH)(CH₃). Evidence for a similar rearrangement reaction has been advanced for N-Nitrosopyrrolidine which is converted to C-nitrosopyrrolidine . The matrix-isolation technique in combination with wavelength-selective irradiation allowed to trap and characterize an intermediate of rearrangement which revealed to be nitroxyl (HNO) complex (CH₂…HNO, CH₃CHO…HNO, CH₃N = CH₂…HNO, and ). Since these findings have a close resemblance with rearrangement reactions of more complex nitrosooxy compounds, nitrosamines, or nitrosohydrazines used in organic synthesis, it is suggested that also in these reactions nitroxyl is present as an intermediate species.     

Modification of poly(vinyl alcohol) through reaction with phosphorus-containing reactants

Crosslinked products of the form: and have been formed from the interfacial condensation of phosphorus diacid halides with poly(vinyl alcohol). Product yield and amounts of phosphorus reactant included in the product increases as the amount of base increases. Product stability in aqueous systems decreases in the order neutral > base > acid.     

High yield synthesis of 4H‐1,4‐benzothiazine‐1,1‐dioxide derivatives

4H‐1,4‐Benzothiazine‐1,1‐dioxide derivatives were synthesized through a sequence of almost quantitative reactions. The commercial starting material 2‐(methylsulfanyl)aniline was Boc‐protected, N‐acylated and oxidized at the sulfur atom to obtain a sulfonyl derivative. An anionic transposition of the acyl group followed by asimultaneous deprotection‐cyclization gave the title products in excellent yields. All products and intermediates were fully characterized.     

Synthesis of titanium polyesters

Titanium polyesters of the form where Cp denotes cyclopentadiene, have been synthesized by utilizing both the interfacial and solution techniques. Polymer yield increases with reaction time. The reactive titanium reactant in the solution polycondensations is believed to be the Cp₂Ti⁺² cation.