Über Chalkogenolate. 171. Reaktion von N,N′-Diphenylformamidin mit Kohlenstoffdisulfid 4. Ester der N,N′-Diphenyl-N-formimidoyldithiocarbamidsäure

On Chalcogenolates. 171. Reaction of N,N′-Diphenyl Formamidine with Carbon Disulfide. 4. Esters of N,N′-Diphenyl-N-Formimidoyl Dithiocarbamic Acid Potassium N,N′-diphenyl N-formimidoyl dithiocarbamate reacts with alkyl halides to yield the corresponding esters \documentclass{article}\pagestyle{empty}\begin{document}${\rm C}_6 {\rm H}_5 {\rm N} = CH - {\rm N}({\rm C}_6 {\rm H}_5) - {\rm CR} - {\rm SR, where R = CH}_3,{\rm C}_2 {\rm H}_5,{\rm CH}_2 - {\rm C}_6 {\rm H}_5,$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}${\rm and (C}_6 {\rm H}_5 {\rm N} = CH - {\rm N}({\rm C}_6 {\rm H}_5) - {\rm CS)}_{\rm 2} = {\rm CH}_2 .$\end{document} The phenyl ester (R = C₆H₅) has been synthesized by reaction of N,N′-diphenyl formamidine with the phenyl ester of chlorodithioformic acid. The prepared compounds have been characterized by means of electron absorption, infrared, nuclear magnetic resonance (¹H and ¹³C), and mass spectra.     

The Radical Anions of 5,5′- and 6,6′-Biazulenyl

ESR. and, in part, ENDOR. studies are reported on the radical anions of 5,5′-and 6,6′-biazulenyl ( 1 and 2 , resp.), as well as on their 1, 1′, 3, 3′-tetradeuterioderivatives ( 1 -d₄ and 2 -d₄). The reduction processes of 1 and 2 leading to these radical anions (\documentclass{article}\pagestyle{empty}\begin{document}$ 1^{\ominus \atop \dot{}}$\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ 2^{\ominus \atop \dot{}}$\end{document}) and the dianions ( ) have been investigated by polarography and cyclic voltammetry. The half-wave reduction potential of 1 and the π-spin distribution in \documentclass{article}\pagestyle{empty}\begin{document}$ 1^{\ominus \atop \dot{}}$\end{document} are consistent with the model of two weakly interacting azulene π-systems, whereas the analogous findings for 2 and \documentclass{article}\pagestyle{empty}\begin{document}$ 2^{\ominus \atop \dot{}}$\end{document} point to a strong interaction between two such systems. This difference can be traced to the distinct inequality ∥c₆₅ ∥ « ∥ c₆₆ ∥ in the LCAO coefficients c_6μ at the centres μ=5 and 6 for the LUMO Ψ₆ of azulene.     

The pK 2 * for the dissociation of H2SO3 in NaCl solutions with added Ni2+, Co2+, Mn2+, and Cd2+ at 25°C

The pK ₂ ^* for the dissociation of sulfurous acid from I=0.5 to 6.0 molal at 25°C has been determined from emf measurements in NaCl solutions with added concentrations of NiCl₂, CoCl₂, McCl₂ and CdCl₂ (m=0.1). These experimental results have been treated using both the ion pairing and Pitzer's specific ion-interaction models. The Pitzer parameters for the interaction of M²⁺ with SO ₃ ^2? yielded $$\begin{gathered} \beta _{NiSO_3 }^{(0)} = - 5.5, \beta _{NiSO_3 }^{(1)} = 5.8, and \beta _{NiSO_3 }^{(2)} = - 138 \hfill \\ \beta _{CoSO_3 }^{(0)} = - 12.3, \beta _{CoSO_3 }^{(1)} = 31.6, and \beta _{CoSO_3 }^{(2)} = - 562 \hfill \\ \beta _{MnSO_3 }^{(0)} = - 8.9, \beta _{MnSO_3 }^{(1)} = 18.7, and \beta _{MnSO_3 }^{(2)} = - 353 \hfill \\ \beta _{CdSO_3 }^{(0)} = - 7.2, \beta _{CdSO_3 }^{(1)} = 13.8, and \beta _{CdSO_3 }^{(2)} = - 489 \hfill \\ \end{gathered} $$ The calculated values of pK ₂ ^* using Pitzer's equations reproduce the measured values to within ±0.01 pK units. The ion pairing model yielded $$\begin{gathered} logK_{NiSO_3 } = 2.88 and log\gamma _{NiSO_3 } = 0.111 \hfill \\ logK_{CoSO_3 } = 3.08 and log\gamma _{CoSO_3 } = 0.051 \hfill \\ logK_{MnSO_3 } = 3.00 and log\gamma _{MnSO_3 } = 0.041 \hfill \\ logK_{CdSO_3 } = 3.29 and log\gamma _{CdSO_3 } = 0.171 \hfill \\ \end{gathered} $$ for the formation of the complex MSO₃. The stability constants for the formation of MSO₃ complexes were found to correlate with the literature values for the formation of MSO₄ complexes.     

Structures and relative energies of gas-phase [C2H7N]+˙ radical cations

Ab initio molecular orbital calculations with split-valence plus polarization basis sets and incorporating electron correlation and zero-point energy corrections have been used to examine possible equilibrium structures on the [C₂H₇N]⁺˙ surface. In addition to the radical cations of ethylamine and dimethylamine, three other isomers were found which have comparable energy, but which have no stable neutral counterparts. These are \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm C}\limits^{\rm .} {\rm H}_{\rm 2} {\rm CH}_{\rm 2} \mathop {\rm N}\limits^{\rm + } {\rm H}_{\rm 3} $\end{document}, \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CH}_{\rm 3} \mathop {\rm C}\limits^{\rm .} {\rm H}\mathop {\rm N}\limits^{\rm + } {\rm H}_{\rm 3} $\end{document}and\documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CH}_{\rm 3} \mathop {\rm N}\limits^{\rm + } {\rm H}_{\rm 2} \mathop {\rm C}\limits^. {\rm H}_{\rm 2} {\rm }, $\end{document} with calculated energies relative to the ethylamine radical cation of ?33, ?28 and 4 kJ mol^?1, respectively. Substantial barriers for rearrangement among the various isomers and significant binding energies with respect to possible fragmentation products are found. The predictions for \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm C}\limits^. {\rm H}_{\rm 2} {\rm CH}_{\rm 2} \mathop {\rm N}\limits^ + {\rm H}_{\rm 3} $\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CH}_{\rm 3} \mathop {\rm C}\limits^{\rm .} {\rm H}\mathop {\rm N}\limits^{\rm + } {\rm H}_{\rm 3}$\end{document} are consistent with their recent observation in the gas phase. The remaining isomer, \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CH}_{\rm 3} \mathop {\rm N}\limits^{\rm + } {\rm H}_{\rm 2} \mathop {\rm C}\limits^{\rm .} {\rm H}_{\rm 2} {\rm },$\end{document}is also predicted to be experimentally observable.     

Vapor-liquid equilibria for polyisobutylene solutions

Vapor sorption isotherms in binary solutions of polyisobutylene (PIB), (M_η = 4.7 × 10⁶ g/mol) in hydrocarbons (cyclopentane; cyclohexane; n-heptane; 2,2-dimethyl butane; and 2,2,4-trimethyl pentane) and chlorinated methanes [carbon tetrachloride (CCI₄) and chloroform (CHCI₃)] have been determined at 23.5°C using the piezoelectric sorption method. The polymer-solvent interaction parameter χ obtained agrees with previously published values determined by using gas-liquid chromatography and a quartz-helix vapor sorption apparatus. The Flory theory of corresponding-states has been applied to the experimental results through the χ parameter and affords a good prediction of the concentration dependence of χ for solutions of chloroform, carbon tetrachloride, n-heptane, and 2,2-dimethyl butane in PIB. The experimental values of \documentclass{article}\pagestyle{empty}\begin{document}$ [\partial (a_1 /\psi _1 )/\partial a_1 ]_{T,P} $\end{document} for the PIB solutions are constant over the measured concentration range, for example \documentclass{article}\pagestyle{empty}\begin{document}$ [\partial (a_1 /\psi _1 )/\partial a_1 ]_{T,P} $\end{document} = ?4.1 for CCI₄, ?3.65 for CHCI₃, ?3.0 for 2,2-dimethyl butane and n-heptane, ?2.7 for 2,2,4-trimethyl pentane, ?2.7 for cyclohexane, and ?1.7 for cyclopentane, where a₁ is the solvent activity and ψ₁ is the solvent segment fraction. The correlations between the values of \documentclass{article}\pagestyle{empty}\begin{document}$ [\partial (a_1 /\psi _1 )/\partial a_1 ]_{T,P} $\end{document} and the theories of Guggenheim, Miller, Huggins, and Flory are discussed.     

Ionic thermal current study of the α′ process in poly(hexamethylene adipamide)

The ionic thermoconductivity (ITC) method has been used to study the α′ transition in the polyamide \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm \hbox{--}\rlap{--} [NH(CH}_{\rm 2} )_6 {\rm NH}\hbox{---} \rm CO(CH_2 )_4 {\rm CO\hbox{--}\rlap{--} ]}_{{\rm x}} $\end{document} (nylon 66). Depending on the thermal history of the sample, the maximum of the thermocurrent peak attributed to the α′ relaxation is found somewhere between ca. 45°C and ca. 66°C; on one heating, it shifts to higher temperatures. The high sensitivity and resolving power of the ITC method permit resolution of this peak into four elementary “pure” activated processes, with constant activation energies in the relevant temperature range. Each of the four corresponding relaxation times follows an Arrhenius law, with a well-defined characteristic temperature T₀ = 83°C at which all these relaxation times are equal. When this last result is interpreted in the light of Eyring's or Bauer's theory, it gives a linear relation between “apparent” activation entropy and activation enthalpy of the elementary processes. The characteristic temperature T₀ is independent of the thermal history of the sample, and the temperature shift of the thermocurrent maximum can be interpreted by the observed variation of the relative intensities of the elementary processes, without modification of their other characteristic features.     

Negative ion mass spectra of a series of fluorinated β-diketones

Electron capture by and the subsequent fragmentation of a series of eleven fluorinated β-diketones of general formula CF₃COCH₂COR has been studied in an MS-50 mass spectrometer. Consecutive loss of two HF molecules from molecular anions occurs with all compounds, as does elimination of CHF₃ from [M ? H]^? ions. Elimination of CO occurs from either \documentclass{article}\pagestyle{empty}\begin{document}$ \left[{{\rm M - HF}} \right]_{}^{_.^ - } $\end{document} or \documentclass{article}\pagestyle{empty}\begin{document}$ \left[{{\rm M - 2HF}} \right]_{}^{_.^ - } $\end{document} ions for five compounds where R ? CF₃ or a cyclic substituent. Kinetic energy release in metastable transitions associated with these HF and CO eliminations has been measured. Intensities of various fragment ions are in part influenced by the ion source temperature. Interaction of \documentclass{article}\pagestyle{empty}\begin{document}$ \left[{{\rm O}} \right]_{}^{_.^ - } $\end{document} reagent ions with five of the β-diketones under chemical ionization conditions gave [M ? H]^? ions as the only significant ion-molecule reaction product.     

Thermische Zerfallsreaktionen von Nitroverbindungen in Stosswellen. III: Dissoziation von 1-Nitropropan und 2-Nitropropan

The pyrolysis of 1- and 2-nitropropane highly diluted in Ar has been studied in shock waves at temperatures K 915 < T < 1200 K and total gas concentrations 7 · 10^?6 mol cm^?3 < [Ar] < 1.5 · 10^?4 mol cm^?3. The reactions behind the shock waves have been followed by recording light absorption-time profiles of the decomposing molecules and the produced NO₂ Under the conditions of the experiments, the primary reaction step in both cases is the C? N bond:fission: \documentclass{article}\pagestyle{empty}\begin{document}$ \begin{array}{rcl} {\rm 1} - {\rm C}_{\rm 3} {\rm H}_{\rm 7} {\rm NO}_{\rm 2} {\rm (} + {\rm M)} &\to & n - {\rm C}_{\rm 3} {\rm H}_{\rm 7} + {\rm NO}_{\rm 2} {\rm (} + {\rm M)\quad k} = 2.3 \cdot 10^{15} {\rm exp }(- 55{\rm kcal mol}^{ - 1} /{\rm RT}){\rm s}^{ - 1} \\ 2 - {\rm C}_{\rm 3} {\rm H}_{\rm 7} {\rm NO}_{\rm 2} {\rm (} + {\rm M)} &\to & i - {\rm C}_{\rm 3} {\rm H}_{\rm 7} + {\rm NO}_{\rm 2} {\rm (} + {\rm M)\quad k} = 2.4 \cdot 10^{15} {\rm exp }(- 54{\rm kcal mol}^{ - 1} /{\rm RT}){\rm s}^{ - 1} \\ \end{array} $\end{document} (first order rate constants k measured at concentrations of [Ar] ? 10^?4 mol cm^?3). At these concentrations the reactions are near to the high pressure limit. By varying the Ar-concentrations over one order of magnitude, only a slight pressure dependence was found. Reaction mechanisms which account for NO₂ removal are discussed.     

An entanglement model for the dependence of fracture surface energy on molecular weight

Over the last decade, empirical evidence has indicated that the effective surface energy γ associated with the fracture of noncrystalline is a linear function of the reciprocal of the viscosity–average molecular weight: \documentclass{article}\pagestyle{empty}\begin{document}$ \gamma = \gamma _\infty - b\bar M_v ^{ - 1} $\end{document}. For poly(methyl methacrylate), data of J. P. Berry, G. C. Berry and Fox show that gamma; ～ 0 at about the same value of M?_v that corresponds to the polymer chain-entanglement length. From this fact, we have developed an entanglement network model for fracture, that bears a resemblance to F. Bueche's entanglement model for the melt viscosity of bulk polymers. Our model allows for the expression of the previously empirical constants, γ_∞ and b, in terms of molecular parameters: \documentclass{article}\pagestyle{empty}\begin{document}$ {{\gamma _\infty = \gamma _{\rm s} A_{\rm s} Z_{\rm c} \rho _{\rm c} N_A } \mathord{\left/ {\vphantom {{\gamma _\infty = \gamma _{\rm s} A_{\rm s} Z_{\rm c} \rho _{\rm c} N_A } {\bar M_{\rm s} }}} \right. \kern-\nulldelimiterspace} {\bar M_{\rm s} }} $\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ b = 2({{\bar M_v } \mathord{\left/ {\vphantom {{\bar M_v } {\bar M_n }}} \right. \kern-\nulldelimiterspace} {\bar M_n }})\gamma _\infty M_{\rm f} $\end{document} where M?_n and M?_f are the number-average molecular weights of the polymer and of the free chain ends, M?_v is the viscosity-average molecular weight, γ_s is the average fracture-energy per entanglement in the craze volume, A_s is the average cross-sectional area of the polymer chain, Z_c and ρ_c are the thickness and density of crazed material on the fracture surface, respectively; M?_s is the average strand molecular weight between entanglements, and N_A is AvogadrO's number.     

Hydrogen migrations in mass spectrometry. III–Energetics of formation of [R′CO2H2]+ in the mass spectra of R′CO2R

The appearance potentials for the [R'CO₂H₂]⁺ ion produced in the fragmentation process \documentclass{article}\pagestyle{empty}\begin{document}$ \left[{{\rm R}^{\rm '} {\rm CO}_{\rm 2} {\rm R}} \right]_{}^{_.^ + } $\end{document} → [R'CO₂H₂]⁺+[R? 2H] have been measured using mono-energetic electron impact techniques for ethyl, n-propyl, and i-propyl formates and acetates. The results indicate that at the threshold the product ion has the protonated acid structure with the hydrogen on the carbonyl and not the hydroxyl group, and that the neutral product for the propyl esters is the allyl radical and not the cyclopropyl radical. For the propyl formates and acetates the appearance potential of the [R'CO₂H₂]⁺ ion is identical with the adiabatic ionization potential of the parent ester (measured by photoelectron spectroscopy) indicating that fragmentation occurs for ground state molecular ions. A two-step mechanism is proposed to rationalize the results.     

Alternating copolymerization of dienes with α-olefins

Alternating copolymerization of butadiene with several α-olefins and of isoprene with propylene were investigated by using a mixture of VO(Acac)₂, Et₃Al, and Et₂AlCl as catalyst. The alternating copolymerization ability of the olefins decreases in the order, propylene > 1-butene > 4-methyl-1-pentene > 3-methyl-1-butene. The study on the sequence of the copolymer of isoprene with propylene by ozonolysis reveals that the polymer chain is reasonably expressed by the sequence \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} [{\rm CH}_{\rm 2} \hbox{--} {\rm CH} \hbox{=\hskip-1pt=} {\rm C(CH}_{\rm 3}) \hbox{--} {\rm CH}_{\rm 2} \hbox{--} {\rm CH(CH}_{\rm 3}) \hbox{--} {\rm CH}_{\rm 2} \rlap{--}]_n $\end{document}. NMR and infrared spectra indicate that the chain is terminated with propylene unit, forming a structure of ?C(CH₃)? CH₂? C(CH₃)?CH₂ involving a vinylene group.     

Laser-induced chemical kinetics: Absolute rate constants for the reactions Ċ2F2 + Br2 → C2F5Br + Ḃr and n-Ċ3F7 + Br2 → n-C3F7Br + Ḃr

Absolute rate constants at room temperature for the metathesis reaction have been measured under VLPP conditions: k₁ = (2.0 ± 0.5) × 10⁸M^?1·s^?1, k₂ = (3.0 ± 0.7) × 10⁸M^?1·s^?1. The radicals were generated through collisionless infrared-multiphoton decomposition of the corresponding iodides by irradiation from a high-power CO₂-TEA laser. The reaction of ?₂F₅ and ?₃F₇ with \documentclass{article}\pagestyle{empty}\begin{document}$$\mathop {\rm N}\limits^{\rm .} {\rm O}_{\rm 2} $$\end{document} are briefly discussed in relation to the reaction of ?₃ with \documentclass{article}\pagestyle{empty}\begin{document}$$\mathop {\rm N}\limits^{\rm .} {\rm O}_{\rm 2} $$\end{document}, which had been measured previously.     

Ein neues Verfahren zur Messung feldstärkeabhängiger Suszeptibilitäten mit der Faraday-Methode,angewandt auf Palladium-Mordenit

A New Method for Measuring Field-dependent Susceptibilities with the Faraday Method, Applied on Palladium Mordenite A simple method to calculate the mean value of an inhomogeneous magnetic field is described, which is needed for susceptibility measurements with a Faraday balance. By combination of the magnetic behaviour of paramagnetic and saturated ferromagnetic calibrating samples we get the magnetic field H = \documentclass{article}\pagestyle{empty}\begin{document}${\rm H} = \frac{{{\rm \sigma}_\infty .{\rm m}_{\rm f}}}{{\chi _{{\rm ges}} \cdot {\rm m}_{{\rm ges}} - \chi _{\rm p}\cdot m_{\rm p}}} $\end{document} $\end{document} (s?_∞ specific saturation magnetization, m mass, χ susceptibility). A Pd-mordenite sample is discussed as an example of a diamagnetic substance with a superparamagnetic impurity. Because the impurity is not magnetically saturated we must take into account the Langevin function. We calculated the diamagnetic susceptibility χ_dia = ?0.411 · 10^?6 cm³/g.     

Polymerization of hexamethylcyclotrisiloxane with a biscatecholsiliconate. I. Nature of polymerization

Polymerization behavior of hexamethylcyclotrisiloxane (D₃) in toluene solution with the use of benzyltrimethylammonium bis(o-p;henylenedioxy)phenylsiliconate as a catalyst, dimethyl sulfoxide as promoter, and adventitious moisture as initiator was investigated. The polymerization system gives a linear difunctional polymer, HO(Me₂SiO)_xH, with a molecular weight which is inversely proportional to the amount of water reacted rather than to the amount of catalyst employed. The polymerization in the presence of H₂O gives rise to molecular weight distributions very close to Poisson distributions. The normalized experimental GPC curve agrees very well with the theoretical GPC curve calculated from the polymerization scheme: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm H}_2 {\rm O} + ({\rm Me}_2 {\rm SiO})_3 \to {\rm HO}({\rm Me}_2 {\rm SiO})_3 {\rm H}} \\ {{\rm HO(Me}_{\rm 2} {\rm SiO)}_{\rm 3} {\rm H} + {\rm N(Me}_{\rm 2} {\rm SiO)}_{\rm 3} \to {\rm HO}({\rm Me}_2 {\rm SiO})_{3(n + 1)} {\rm H}} \\ \end{array} $$\end{document} Polymerization carried out in the combined presence of H₂O and ROH, where R is Me or Me₃Si, gives rise to bimodal molecular weight distributions. The resulting polymers consist of HO(Me₂SiO)_2xH and RO(Me₂SiO)_xH. The molecular weight of the former is twice that of the latter, and their proportion depends on the ratio of H₂O to ROH. The system is a special type of “living” polymer.     

Reaction of silicon hydrides with primary aliphatic amines

Conclusions The direction of the reaction of the silicon hydrides: R₂SiH₂, RSiH₃, and with primary aliphatic amines, in the presence of catalysts based on Group VIII compounds, as a function of the structure of the silicon hydride and the nature of the employed catalyst, was established.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2330–2333, October, 1972.     

Synthese von diastereo- und enantio-selektiv deuterierten β,ε-, β,β-, β,γ- und γ,γ-Carotinen

Synthesis of Diastereo- and Enantioselectively Deuterated β,ε-, β,β-, β,γ- and γ,γ-Carotenes We describe the synthesis of (1′R, 6′S)-[16′, 16′, 16′-²H₃]-β, εcarotene, (1R, 1′R)-[16, 16, 16, 16′, 16′, 16′-²H₆]-β, β-carotene, (1′R, 6′S)-[16′, 16′, 16′-²H₃]-γ, γ-carotene and (1R, 1′R, 6S, 6′S)-[16, 16, 16, 16′, 16′, 16′-²H₆]-γ, γ-carotene by a multistep degradation of (4R, 5S, 10S)-[18, 18, 18-²H₃]-didehydroabietane to optically active deuterated β-, ε- and γ-C₁₁-endgroups and subsequent building up according to schemes \documentclass{article}\pagestyle{empty}\begin{document}${\rm C}_{11} \to {\rm C}_{14}^{C_{\mathop {26}\limits_ \to }} \to {\rm C}_{40} $\end{document} and C₁₁ → C₁₄; C₁₄+C₁₂+C₁₄→C₄₀. NMR.- and chiroptical data allow the identification of the geminal methyl groups in all these compounds. The optical activity of all-(E)-[²H₆]-β,β-carotene, which is solely due to the isotopically different substituent not directly attached to the chiral centres, is demonstrated by a significant CD.-effect at low temperature. Therefore, if an enzymatic cyclization of [17, 17, 17, 17′, 17′, 17′-²H₆]lycopine can be achieved, the steric course of the cyclization step would be derivable from NMR.- and CD.-spectra with very small samples of the isolated cyclic carotenes. A general scheme for the possible course of the cyclization steps is presented.     

Bifunctional even-electron ions. II. Fragmentation behaviour of aliphatic ω-hydroxy and ω-methoxy methoxonium ions

Bifunctional methoxonium ions \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm R} -\mathop {\rm C}\limits^ + ({\rm OCH}_3 ) - ({\rm CH}_2 )_{\rm n} - {\rm OH}({\rm b}) $\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm R} - \mathop {\rm C}\limits^ + ({\rm OCH}_3 ) - ({\rm CH}_2 )_{\rm n} - {\rm OCH}_3 ({\rm c}) $\end{document} (c) show as the main reactions those caused by functional group interaction, as has already been found for the analogous hydroxonium ions (g). Although there are similarities in the fragmentation behaviour of the isomeric ions b and g, their fragmentation pathways are different, proving b and g as distinct species. The dominant primary fragmentation for b and c is loss of CH₃OH. The hydrogen migrations prior to this reaction have been established by deuterium labelling. The findings on the fragmentation behaviour of the bifunctional methoxonium ions have been extended to the general behaviour of hydroxy and alkoxy substituted alkoxonium ions.     

High temperature polymers. I.—Sulfone ether diamines as intermediates for tractable high temperature polymers

A useful synthesis of a series of new aromatic sulfone ether diamines, H₂NC₆H₄O\documentclass{article}\pagestyle{empty}\begin{document}$\hbox{---}\hskip-5pt[\ {\rm C}_{\rm 2} {\rm H}_{\rm 4} {\rm SO}_{\rm 2} {\rm C}_{\rm 6} {\rm H}_{\rm 4} \hbox{--} {\rm ORO}\hbox{---}\hskip-5pt ]_n {\rm OC}_{\rm 6} {\rm H}_{\rm 4} {\rm SO}_{\rm 2} {\rm C}_{\rm 6} {\rm H}_{\rm 4} \hbox{---} {\rm OC}_{\rm 6} {\rm H}_{\rm 4} {\rm NH}_{\rm 2} $\end{document}, where n = 0, 1, 2…, which increases the tractability of polyimides, polyamide-imides, and polyamides, was developed. These diamines were prepared by condensing various proportions of sodium p-aminophenate, sodium bisphenates, and dichlorodiphenyl sulfone. The synthetic procedures are now refined to the point where simply coagulating these diamines into water yields high purity polymer-grade sulfone ether diamines. The latter have good tractability; and in some cases, it is possible to extrude and injection-mold these high temperature polymers.     

Polymerization of σ-bonded organo-transition metal derivatives of styrene

Five new monomers of transition metal complexes containing a styryl group, trans-\documentclass{article}\pagestyle{empty}\begin{document}$ {\rm Pd}({\rm PBu}_{\rm 3})_2 \rlap{--} ({\rm C}_6 {\rm H}_4 {\rm CH} \hbox{=\hskip-2pt=} {\rm CH}_2 ){\rm X\ X \hbox{=\hskip-2pt=} Cl(Ia),\ X \hbox{=\hskip-2pt=} Br(Ib)},\ {\rm X \hbox{=\hskip-2pt=} CN(Ic),\ X \hbox{=\hskip-2pt=} Ph(Id)} $\end{document} and trans-\documentclass{article}\pagestyle{empty}\begin{document}${\rm Pt(PBu}_{\rm 3} {\rm )}_{\rm 2} \rlap{--} ({\rm C}_{\rm 6} {\rm H}_{\rm 4} {\rm CH} \hbox{=\hskip-2pt=} {\rm CH}_2 ){\rm Cl}({\rm II})$\end{document}, were synthesized. The monomers were readily homopolymerized in benzene with the use of AIBN or BBu₃–oxygen as the initiator. Copolymerization of Ia with styrene was carried out by using AIBN. From the Cl content of the copolymers by analysis, monomer reactivity ratios and Q–e values were obtained as follows: r₁ = 1.49, r₂ = 0.45; Q₂ = 0.41, e₂ = ?1.4 (M₁ = styrene, M₂ = Ia). Based on the above data, the σ-bonded palladium moiety at para position of styrene acts as a strongly electron-donating group to the phenyl ring. This is also supported by the olefinic β-carbon chemical shift of ¹³C NMR for Ia.     

Thermochemistry of 2-Aminopyridine (C<Subscript>5</Subscript>H<Subscript>6</Subscript>N<Subscript>2</Subscript>)(s)

The molar enthalpies of solution of 2-aminopyridine at various molalities were measured at T=298.15 K in double-distilled water by means of an isoperibol solution-reaction calorimeter. According to Pitzer’s theory, the molar enthalpy of solution of the title compound at infinite dilution was calculated to be D_solH_m^￥ = 14.34 kJ·mol^-1\Delta_{\mathrm{sol}}H_{\mathrm{m}}^{\infty} = 14.34~\mbox{kJ}\cdot\mbox{mol}^{-1}, and Pitzer’s ion interaction parameters b_MX^(0)L, b_MX^(1)L\beta_{\mathrm{MX}}^{(0)L}, \beta_{\mathrm{MX}}^{(1)L}, and C_MX^fLC_{\mathrm{MX}}^{\phi L} were obtained. Values of the relative apparent molar enthalpies ( ^φ L) and relative partial molar enthalpies of the compound ([`(L)]₂)\bar{L}_{2}) were derived from the experimental enthalpies of solution of the compound. The standard molar enthalpy of formation of the cation C₅H₇N₂ ⁺\mathrm{C}_{5}\mathrm{H}_{7}\mathrm{N}_{2}^{ +} in aqueous solution was calculated to be D_fH_m^o(C₅H₇N₂⁺,aq)=-(2.096±0.801) kJ·mol^-1\Delta_{\mathrm{f}}H_{\mathrm{m}}^{\mathrm{o}}(\mathrm{C}_{5}\mathrm{H}_{7}\mathrm{N}_{2}^{+},\mbox{aq})=-(2.096\pm 0.801)~\mbox{kJ}\cdot\mbox{mol}^{-1}.