The effect of environment on the reactions of thiiranium ions

The thiiranium ion formed by the reaction of $\text{Z}$-1-phenylpropene and (4-ClC₆H₄S)₂SC₆H₄ClSbCl₆ in CH₂Cl₉ at ?70°C reacts with Cl^? to form both $\text{erythro}$- and $\text{threo}$-Markownikoff B-chlorosulfides.     

Reactions of in-situ generated acyllithium reagents with carbon disulfide and carbonyl sulfide

In-situ generated (at ?110°C to ?135°C) acyllithium reagents, RC(O)Li (R = $\text{t}$-Bu, $\text{n}$-Bu), react with CS₂, to give [RCOS]Li with loss of Cs. On the other hand, COS reacts to give [RC(O)COS]Li.     

Some advances in the liquid-phase autoxidation of organic compounds of the non-transitional elements

Dicrotylzinc (I) adds to CC double bonds in olefins even at temperatures between 20 and 60°. With ethylene bis(3-methyl-4-pentenyl)zinc (II) is formed selectively, and with 1-octene the $\text{1}\text{1}$ adduct as which is derived from the 1-methyl-2-propenyl form of (I) is formed almost exclusively. In the reactions with styrene and butadiene metal-to-C(1) addition competes with metal-to-C(2) addition: with butadiene, products which are derived from the 2-butenyl structure of (I) are formed in only 3–13% yield. In comparison with crotylmagnesium and crotylaluminium, (I) reacts more selectively to give products derived from the 1-methyl-2-propenyl form.     

Flash-thermolysis of methylenephtalide and 3-methylene-2-coumaranone

The synthesis and flash-thermolysis of methylenephtalide $\text{1}$ and 3-methylene- 2-coumaranone $\text{2}$ are reported. At high temperatures ( ? 1000°C) these two isomeric lactones do not extrude CO₂ but give rise to new clean thermal rearrangements.     

Cycloadditions des arsoles a haute temperature

At room temperature 1-phenyl-2,5-dimethylarsole $\text{1}$ gives [4+2] cycloadditions with dienophiles whereas at 160 °C it yields arsenic atoms which react with tolane to give the 1,4-diarsabicyclo[2.2.2]octatriene $\text{8}$; 1,2,5-triphenylarsole $\text{2}$ is less reactive at room temperature but isomerizes at 160°C to give the 2$\text{H}$-arsole $\text{5}$ which reacts as a diene with tolane to yield the 1-arsanorbornadiene $\text{6}$, and as a dienophile through its AsC double bond with dimethylbutadiene to give the 1-arsabicyclo[4.3.0]nonadiene $\text{7}$.     

High-pressure/high-temperature phase relations and vibrational spectra of CsSbF6

CsSbF₆(II) under ambient conditions is trigonal, space group $\text{D}{}_{\mathrm{3d}}{}^5\text{-R}\text{3}\text{m}$. At 187.8°C it undergoes a phase transition with an enthalpy change of 5.267 ± 0.316 kJ mole^?1, to phase CsSbF₆(I). CsSbF₆ decomposes with loss of fluorine at atmospheric pressure at high temperatures, but under pressure the decomposition is prevented and a melting point of 310°C at atmospheric pressure can be inferred. The $\text{II}\text{I}$ phase boundary and melting curve were studied as functions of pressure. The infrared and Raman spectra of CsSbF₆(II) were studied in the temperature range of ?256 to 20°C, at ambient pressure. The crystal chemistry of the CsSbF₆ and its relationship with other related compounds is discussed.     

Crystal preparation and properties of cesium tin(II) trihalides

Synthesis methods for cesium tin(II) trihalides via aqueous solution and from the melts of anhydrous halides, which ensure freedom from oxidation and the effects of traces of water, are described. The halide compounds CsSnCl₃, CsSnBr₂Cl, CsSnBr₃, CsSnBr₂I, CsSnBrI₂, and CsSnI₃ all have the cubic perovskite structure at elevated temperatures, and all but the first two are good electrical conductors in this form. The growth of single crystals from the melt, and by vapor transport, is outlined.The ${}^{35}\text{Cl}$ nuclear quadrupole resonance spectrum of monoclinic CsSnCl₃ consists of three lines, with frequencies 9,799, 11.005, and 11.695 MHz at 25°C, confirming the presence of pyramidal SnCl₃^? ions in this structure. In CsSnBr₃, there is a single ${}^{81}\text{Br}$ nuclear quadrupole resonance line, with frequency 63.073 MHz at 25°C, which splits into two lines on cooling the sample below 19°C. The low-temperature form of CsSnBr₃ apparently has a tetragonally distorted perovskite structure, with a = 11.59 and c = 11.61 Å at 12°C. A single ${}^{127}\text{I}$ nuclear quadrupole resonance line was observed in the low temperature orthorhombic form of CsSnI₃, with frequency 79.707 MHz at 25°C, and the variation of the frequency of this line with temperature may indicate a minor phase change in CsSnI₃ at 35°C.     

Thermodynamic studies of the phase relationships of nonstoichiometric cerium oxides at higher temperatures

Partial molar thermodynamic quantities for oxygen in nonstoichiometric cerium oxides were determined by thermogravimetric analysis in $\text{CO}\text{CO}{}_2$ mixtures in the temperature range 900–1400°C. Under these conditions compositions within the range $\text{2.00 ?}\text{O}\text{M}\text{? ～1.75}$ could be obtained. A detailed analysis of the data shows that the α′-phase region in the phase diagram, previously described as a grossly nonstoichiometric phase, can be divided into several subregions each consisting of an apparent nonstoichiometric single phase. The finer details of the thermodynamic data, however, suggest that some of these subregions can be further split into ordered intermediate phases with compositions following the series M_nO_2n?2.Supplementary high-temperature X-ray diffraction studies under vacuum were made at temperatures up to 855°C. At the higher temperatures between 790 and 855°C, a new phase of low symmetry was obtained. Indexing of the powder pattern for this phase showed it to be isostructural with Pr₆O₁₁ and with a monoclinic unit cell with a = 6.781 ± 0.006Å, b = 11.893 ± 0.009 Å, c = 15.823 ± 0.015 Å, and β = 125.04 ± 0.04°.     

Carbene chemistry. Part 13 [1]. Preparation of sole fluoroallenes by a carbene route,and the reaction of allenes with halogenocarbenes

Fluoroallene and 1, 3-difluoroallene are prepared in good overall yield by the addition of dichlorocarbene to vinyl fluoride and 1, 2-difluoroethylene respectively, followed by pyrolysis of the dichlorocyclopropanes and treatment of the resulting dichloropropenes with zinc. Pyrolysis of 1, 1-dichloro-2-fluorocyclopropane over zinc gives fluoroallene directly.The reaction of allene with 2, 2, 3-trifluoro-3-trifluoro- methyloxiran at 180°C as a source of difluorocarbene gives both 1, 1-difluoro-2-methylenecyclopropane and its rearrangement product 1-(difluoromethylene)cyclopropane, the latter reacting more readily with a second difluorocarbene to give 2, 2, 3, 3- tetrafluorospiropentane. In an analogous way, fluoroallene reacts with dichlorocarbene, generated from trifluoro(trichloromethyl) silane at 140°C, to give $\text{E}$- and $\text{Z}$-1, 1-dichloro-2- (fluoromethylene)cyclopropane, 1-(dichloromethylene)-2-fluorocyclopropane, and 2, 2, 3, 3-tetrachloro-4-fluorospiropentane.     

Transient spectrum from nanosecond pulse radiolysis of liquid ammonia

In addition to the absorption of the ammoniated electron, the transient absorption spectrum of irradiated liquid ammonia contains two ultraviolet bands at 250 nm and 320 nm. The latter is shown to be due neither to the NH₂^? ion nor to NH singlet. There is conflicting evidence concerning its possible assignment to NH triplet. The C value of the ammoniated electron has been found to be 3.0 at ?48°C. At ?45°C, the ammoniated electron decays with concurrent first and second order kinetics and it reacts with Cu²⁺ with the rate constant 1.5 × 10¹¹$\text{l}$ mole^?1 sec^?1.     

Contributionàl'étude du système formépar l'étain,le soufre et l'iode. Mise enévidence des deux variétés de l'iodosulfure stanneux Sn2SI2: Comportement thermique etétude structurale

We have found a new compound Mn₈O₁₀Cl₃. It is prepared by oxidation of anhydrous or hydrated MnCl₂ in streaming (N₂ + O₂) at temperatures less than 680°C. At room temperature the compound is tetragonal, a = b = 9.2898 Å, c = 13.0247 Å. The more symmetric space group is $\text{I4}\text{mmm}$. Mn₈O₁₀Cl₃ becomes cubic at 360°C with the c-axis as cubic parameter. In air, DTA and GTA have shown that Mn₈O₁₀Cl₃ is transformed at 580°C into Mn₂O₃ which gives Mn₃O₄ at 960°C. The exact formula has been determined only by crystal structure analysis.     

Katalytische reaktionen von aminen mit olefinen

Tetramethylethylenediamine (TMED) reacts with ethylene (propene) under the influence of catalytic amounts of alkyllithium to give dimethylvinylamine and dimethylethylamine (dimethylisopropylamine). In competitive reactions alkyl-lithium and the amides formed by this with primary or secondary amines in presence of tetramethylethylenediamine enhance the addition of primary or secondary amines to ethylene more strongly than in the absence of the diamine. The pressures are $\text{1}\text{5}$ to $\text{1}\text{10}$ of those needed when sodium catalysts are used and the temperatures required are 50–100° lower. Dimethylamine but not diethylamine, which however reacts with cycloolefins containing strained double bonds, adds to propene.     

Study by gas-liquid chromatography of the thermodynamics of the interaction of poly(vinyl acetate) with various solvents

The solubility parameter of poly(vinyl acetate) at various temperatures has been obtained by using the method developed by DiPaola-Baranyi and Guillet, Marcomolecules11, 228 (1978). The solubility parameter of polymer at 25°C was found to be $\text{10.1 (}\text{cal/cm}{}^3\text{)}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ by linear extrapolation from higher temperatures (70–140°C). The interaction parameter χ of polymer in various solvents, at temperatures below the melting point T_m, has been determined by means of the solubility parameters of the polymer and solvents at this temperature, deduced from their values obtained chromatographically at higher temperatures. The value of the interaction parameter so obtained is in good agreement not only with values calculated by other techniques but also is independent of the temperature range used for the chromatographic measurements. Moreover, using the equation-of-state theory formulation, we have determined the values of the interaction parameters $\text{χ}{}^1$ for various systems poly(vinyl acetate)/probes and from it the contact interaction energy, X₁₂, in the temperature range 70–140°C.     

Synthesis of “capped porphyrins”

The synthesis of “capped porphyrins” ($\text{10}$), ($\text{18}$), and ($\text{28}$), and their (chloro)iron(III), iron(II), cobalt (II), and zinc(II) complexes is reported. These complexes serve as models for the active site of the oxygen binding haemoproteins. In addition to reversible binding of dioxygen by each of the iron (II) porphyrin complexes, the 1-methyl-imidazole-(“C₃-capped porphyrin”) iron (II) complex ($\text{23}$) reacts reversibly with carbon monoxide, in solution at 25°C.     

Wide-band proton NMR study of a new hydrate WO3 · 13H2O in the powder form

The proton NMR of a new hydrate $\text{WO}{}_3\text{·}\text{1}\text{3}\text{H}{}_2\text{O}$ as a powder was studied between ?140 and 100°C. The lattice can be considered as “rigid” at temperatures below ?80°C. The structural water corresponding to the above formula is coordinated in the form of water molecules. Above ?80°C it undergoes thermally activated hindered rotation. The compound also retains adsorbed surface “water,” partly in the form of strongly bonded OH groups, partly in the form of water molecules. Degassing at 175°C and 10^?4 Torr removes the adsorbed molecular water but leaves OH groups bonded to the surface.     

Détermination par spectrophotométrie d'absorption du potentiel normal du couple Cu(II)/Cu(I) dans les chlorures alcalins fondus

The reaction Cu²⁺ + Cl^? ? Cu⁺ + $\text{1}\text{2}$ Cl₂ has been studied in three different solvents—LiCl—KCl (70–30 % mol), eutectic LiCl–KCl (58–42 % mol) and LiCl–CsCl (55–45 % mol) at different temperatures by visible and near i.r. spectrophotometry. Equilibrium constants are calculated. The standard potential of the couple Cu²⁺/Cu⁺ with reference to the standard potential of Cl₂/2Cl^?, as well as the thermodynamic quantities $\text{Δ}\text{H}$ and $\text{Δ}\text{S}$ in the range 400–600 °C, have been deduced.     

An electron microscope study of the FeOFe2O3TiO2 system and of the nature of iron-doped rutile

An electron microscope study of FeOFe₂O₃TiO₂ reveals a wide range of unsuspected CS behavior. At 1300°C, isolated {132} faults (MX_1.995) coexist with aggregated {121} CS planes (MX_1.97). At lower temperatures, no aggregated faults occur and isolated faults swing towards {011}; these are often stepped and are accompanied by a high dislocation density. Above 1400°C, elements of (121) and (132) intergrow, forming intermediate high-index CS structures whose indices depend on oxygen/metal ratio, $\text{Fe}{}^{\mathrm{3+}}\text{Fe}{}^{\mathrm{2+}}$ ratio, and temperature. At a given temperature, and in air, there is a range of oxygen/metal ratios where the CS plane swings continuously from (132) to (121); the width of this range increases with increasing temperature (1.97-1.93 at 1500°C). The observations suggest a mechanism for transforming from rutile to α-PbO₂-derived CS structures. Pseudobrookite is incoherent with rutile, coexisting with slightly reduced rutile (MX_1.995) below about 1200°C but with ordered CS structures above this. Wavy domain boundaries and a new superstructure appear in beam-heated pseudobrookite.     

A variable temperature study of the 19-F N.M.R. spectrum of perfluorohexamethyltetrazan: Novel restricted rotation and hindered inversion at the nitrogen atoms [1]

At low temperatures, the ¹⁹F n.m.r. spectrum of the tetrazan (CF₃)₂NN(CF₃)N(CF₃)N(CF₃)₂ shows the presence of two isomers with a free energy difference in stability Δ$\text{G}$ of 2.2 kJ mol^-1. Both isomers show three types of CF₃ group which coalesce at -15°C to three systems of equal intensity (Δ$\text{G}$≠ 52 kJ mol^-1). At 40 °C the two signals assigned to the terminal CF₃ groups coalesce to a single band (Δ$\text{G}$≠ 65 kJ mol^-1).The behaviour is discussed in terms of restricted inversion at the nitrogen atoms, and hindered rotation about the N-N bonds.The hydrazines (CF₃)₂NN(CF₃)NO and (CF₃)₂NN(CF₃)NO₂ have temperature independent spectra.     

1,6-dithia-spiro[4.4]nonadiene aus 2-thiazolin-5-thionen

4,4-Dimethyl-2-phenyl-2-thiazolin-5-thione ($\text{4}$) reacts with 2,3-diphenylcyclopropenone ($\text{2a}$) at 145°C and with benzonitrilio-2-propanide ($\text{6}$) at room temperature to yield the 1,6-dithia-spiro[4.4]nonadienes $\text{5}$ and $\text{7}$, respectively.     

Comparative reactions between aziridines and F2, COF2, CF3OF

In CFCl₃, aziridines $\text{I}$ react with F₂(6 %/N₂,  20°C), COF₂ (20 %/N₂,  40°C) and CF₃OF [1] (20 %/N₂,  40°C).Substitution products are obtained : l-(aziridine)carbonyl fluorides $\text{II}$ and l-Fluoroaziridines $\text{III}$

In (Et)₂O, aziridines $\text{I}$ react with COF₂ (20 %/N₂, 10°C) and we have the carbonyl fluorides $\text{IV}$.

Products IV can be thermally decomposed into β fluoro isocyanates.In CFCl₃, N substituted aziridines $\text{V}$ react with F₂(6%/N₂, 20°C) and with CF₃OF [2] (20%/N₂, 40°C). No reaction is observed with COF₂in our conditions (5% to 25%/N₂, 80°C to + 40°C).Addition products are obtained : N Fluoro amines β fluorinated $\text{VI}$, N Fluoro and NN difluoro amines β trifluoro methoxylated $\text{VII}$ and $\text{VIII}$.

with R = SO₂Ø, COØNO₂, Cl.