Kinetische und thermodynamische Untersuchungen im System AgCl-LiCl-NaCl

In the ternary system silver chloride-lithium chloride-sodium chloride the kinetics of the galvanic deposition of silver on graphite electrodes was investigated as well as its dissolution without current in the molten salt saturated with chlorine gas.In addition the emf-values were measured in the temperature range between 923 K and 1,173 K by means of, the formation cell graphite/Ag(s)/AgCl(l)–LiCl(l)–NaCl(l)/Cl₂ graphite From these data the partial molar free excessGibbs energies were calculated. Using the equation for a multicomponent system as suggested byRedlich-Kister ¹ G _AgCl ^E values were obtained by a non-linear fitting process, where the fit was performed for all investigated temperatures and over the entire concentration range in the ternary system. With the parameters obtained the partial and integral excess valuesG _i ^E ,G ^E ,H _i ^E ,H ^E ,S _i ^E andS ^E were calculated.

     

Kinetics of electrode reaction coupled to ion transfer across the liquid/liquid interface

In the theoretical model it is assumed that a graphite disk electrode is covered by a thin film of solution of decamethylferrocene (dmfc) and some electrolyte CX in nitrobenzene and immersed in an aqueous solution of the electrolyte MX. Oxidation of dmfc is accompanied by the transfer of anion X ⁻ from water into nitrobenzene since it is also assumed that cations dmfc ⁺ and C ⁺ are insoluble in water and cation M ⁺ is insoluble in nitrobenzene. Kinetic parameters of the electrode reaction can be determined if the total potential difference across the nitrobenzene/water interface is maintained constant by adding the electrolytes CX and MX in concentrations which are much higher than the initial concentration of dmfc in nitrobenzene.     

Thallium silver chalcogenides of the orderedanti-PbCl2-structure type

TlAgS, TlAgSe and TlAgTe crystallize with the orderedanti-PbCl₂-structure type, space group Pnma,Z=4. The lattice constants are: TlAgS:a=722.8(3).b=446.6(1),c=833.1(2)pm. TlAgSe:a=747.56(3),b=463.75(2),c=869.0(1) pm. TlAgTe:a=775.9(1),b=486.8(1),c=877.3(2) pm. The crystal structure of TlAgSe was refined from single crystal diffractometer data to a conventionalR-factor of 0.045. The relationship with the BaCu₂S₂-structure type is discussed.On leave from Institute of Inorganic Chemistry, University of Vienna A-1090, Wien, Austria     

Thermodynamische Untersuchungen ann-Alkan/n-Alkin-Systemen

Heats of mixing (H ^E)ofn-octane with 1,2,3,4-isomers ofn-octyne,n-heptane withn-1-heptyne andn-nonane withn-1-nonyne at temperatures from 298.15 to 318.15 K were measured with aCalvet-type microcalorimeter. The results are presented in tables and correlated with theRedlich-Kister equation.

     

Schiff base complexes of dioxouranium(VI). VII. Dioxouranium(VI) acetate complexes with monobasic bidentate and bibasic tridentateSchiff bases

11 and 12 molar reactions of dioxouranium(VI) acetate dihydrate with the monobasic bidentateSchiff bases,o-HOC₆H₄CH=NR oro-HOC₁₀H₆CH=NR (R=C₂H₅,n-C₃H₇,n-C₄H₉ or C₆H₅) and bibasic tridentateSchiff bases,o-HOC₆H₄CH=NR(OH) oro-HOC₁₀H₆CH=NR(OH) (R=–CH₂CH(CH₃)- or —CH₂CH₂CH₂–) have been studied and derivates of the type UO₂(OAc)₂(SBH), UO₂(OAc)₂(SBH)₂, UO₂(OAc)₂(SBH ₂) and UO₂(OAc)₂(SBH ₂)₂ (whereSBH andSBH ₂ represent monobasic bidentate and bibasic tridentateSchiff base molecules respectively) have been isolated. These have been characterized by elemental analysis, conductance measurements and IR spectral studies.

---

UO₂ ²⁺-Komplexe von Schiff-Basen. VII. Uranylacetat-Komplexe mit monobasischen zweizähnigen und bibasischen dreizähnigen Schiff-Basen

Zusammenfassung Es wurden in 1:1- und 1:2-molaren Reaktionen von UO₂(OAc)₂·2H₂O mitSchiff-Basen (L) Komplexe des Typs UO₂(OAc)₂ L bzw. UO₂(OAc)₂ L ₂ isoliert. Die Komplexe wurden mittels Elementaranalyse, Leitfähigkeitsmessungen und IR-Spektren untersucht.

     

Die Darstellung der Oligosilane Si8 X 18 (X-Cl,OCH3) durch Photolyse von Silylquecksilberverbindungen

The formation of SiSi-bonds by a photochemical reaction of silylmercury compounds is described. The silylmercury compounds [(X ₃Si)₃Si]₂Hg (X=Cl, OCH₃) were synthesized via theVyazankin Hydrid method with (X ₃Si)₃SiH and Bis(t-butyl)mercury. By UV-irradiation of these products in hexane as a solvent, the oligosilanes [(X ₃Si)₃Si]₂ are formed in good yields. All these compounds are charactericed by spectroscopical methods.

     

Untersuchungen zurFriedel-Crafts-Reaktion. XVI. Darstellung isomerer 2-Acyl- und 3-Acyl-4-methoxyphenole

Acylation of 4-methoxy phenol according toFriedel andCrafts, as well as the rearrangement of its esters according toFries lead always to 2-acyl-4-methoxy phenols or to their demethylated compounds. The unknown 3-acyl-4-methoxy phenols were prepared in two steps: First, the ester is acylated with the corresponding acyl chloride and SnCl₄ in nitromethane. In the second step the resulting ketoesters are hydrolysed. This is a general method. The yields ofmeta-acylphenols are between 40 and 90%. The isomeric 2-acyl-4-methoxy-phenols which were partly unknown or accessible only in low yields have also been prepared for comparative spectral studies (UV, IR, NMR, MS) ofortho- andmeta-acylphenols.

     

Prins-Reaktionen mit Arylaldehyden, 5. Mitt.: Zur Umsetzung mit 2-Buten und mit Cyclohexen

By reaction of 2-[(1RS, 2RS)-2-hydroxy-1-methyl-propyl]-2-phenyl-1,3-dithiane (1 a) withcis-2-butene oxide, subsequent reduction and acetalizationc-4,t-5-dimethyl-r-2,c-6-diphenyl-1,3-dioxane (3 a) andt-4,c-5-dimethyl-r-2,c-6-diphenyl-1,3-dioxane (3 b) were synthesized as model compounds. For the same purpose by aldol reaction of cyclohexanone and reduction (1RS, 2SR)-2[(RS)-hydroxy-(4-methoxyphenyl)methyl]cyclohexanol (7 a), (1RS, 2RS)-2[(SR)-hydroxy-(4-methoxyphenyl)methyl]cyclohexanol (8 a), and (1RS, 2RS)-2[(RS)-hydroxy-(4-nitrophenyl)methyl]cyclohexanol (8 b) and by acetalization (2 , 4 , 4 a, 8 a)-2,4-bis(4-methoxyphenyl)hexahydro-4H-1,3-benzodioxin (9 a) and (2 , 4 , 4 a, 8 a)-2,4-bis(4-nitrophenyl)hexahydro-4H-1,3-benzodioxin (10 b) were obtained. FromPrins reactions, starting with 2-butene3 a,c-4,c-5-dimethyl-r-2,c-6-diphenyl-1,3-dioxane (3 c),r-4,t-5-dimethyl-c-6-phenyl-1,3,2-dioxathiane-2,2-dioxide (4), and (2Z, 4E)-1,5-diphenyl-4-methyl-2,4-pentadien-1-on (5), and starting with cyclohexene (E)-3-(4-methoxybenzylidene)cyclohexenyl-4-methoxyphenyl ketone (11) have been isolated in low yields.

4. Mitt.:Griengl, H., Nowak, P., Mh. Chem.109, 11 (1978).     

Magnetische Messungen im Nahordnungsbereich vonHeusler-Phasen (Co,T)2 XY

Magnetic measurements onHeusler alloys (Co,T)₂ XY (field and temperature dependence) are performed around theCurie points (temperature range:T _C–50 toT _C+50). A method otherwise used to get rid of ferromagnetic impurities only ( _g versus 1/H plot) is applied to pure ferromagnets and yields completely new _g (extrap.) versusT curves with a maximumT _max> T _C. The method was applied to pure gadolinium first which has aCurie point within the accessible region of the susceptibility measuring device.

     

The vibrational spectra of linear and branched perchlorosilanes Si n Cl2n+2 and their simulation using a local symmetry force field

Infrared andRaman vibrational spectra ofn-Si₄Cl₁₀,n-Si₅Cl₁₂,neo-Si₅Cl₁₂ and [(SiCl₃)₃Si]₂ have been measured and assigned. A local symmetry force field has been developed to simulate vibrational spectra of all (noncyclic) perchlorosilanes Si _n Cl_2n+2 known today (n=2, 3, 4, 5, 8). The observed spectra are reproduced satisfactorily

---

Die Vibrationsspektren linearer und verzweigter PerchlorsilaneSi _n Cl _2n+2 und deren Simulierung mittels eines lokalen Symmetrie-Kraftfeldes

Zusammenfassung Infrarot- undRaman-Spektren vonn-Si₄Cl₁₀,n-Si₅Cl₁₂,neo-Si₅Cl₁₂ und [(SiCl₃)₃Si]₂ wurden aufgenommen und zugeordnet. Ein lokales Symmetrie-Kraftfeld zur Simulation der Spektren aller bisher bekannten (nicht cyclischen) Perchlorsilane Si _n Cl_2n+2 (n=2, 3, 4, 5, 8) wird angegeben. Die beobachteten Spektren werden zufriedenstellend reproduziert

     

The Synthesis of Cyclopenta[<Emphasis Type="Italic">c</Emphasis>]pyridine (2-Pyrindene) Derivatives

Summary. Ethyl 2-(N-morpholinyl)cyclopent-1-ene-1-carboxylate reacted smoothly with cyanothioacetamide to give morpholinium 4-cyano-1-oxo-2,5,6,7-tetrahydro-1H-cyclopenta[c]pyridine-3-thiolate; the former when treated with N-benzyl-α-chloroacetamide gave either a S-alkyl derivative or cyclopenta[d]thieno[2,3-b]pyridine, depending on the reaction conditions. Under Mannich-type aminomethylation with primary amines and formaldehyde the above thiolate afforded derivatives of the previously unknown heterocyclic system, cyclopenta[g]pyrido[2,1-b][1,3,5]thiadiazine in 81–90% yields. Victor P. Litvinov, was Deceased Victor P. Litvinov, This paper is dedicated to the blessed memory of our colleague, Prof. Victor Petrovich Litvinov (Dec 24, 1932–Feb 26, 2007)     

Die Kristallstruktur des Komplexnitrides NbMoN1−x (x≤0,1)

The crystal structure of NbMoN_1–x has been determined from X-ray powder patterns. It is isotypic with the formerly described^1,2 complex nitrides NbCrN and Ta_1–x Cr_1+x N. The tetragonal unit cell contains 6 atoms and belongs to the space groupP4/nmm-D _4h ⁷. The lattice parameters are:a=3,095 Å,c=7,799 Å. The structure is characterized by relatively close packed double layers of Nb-atoms and Mo-atoms parallel to the base plane. The nitrogen atoms are within the octahedral interstitial sites.

     

Das Schwingungsspektrum von Barium-Divanadat

The infrared and laser-Raman spectra of crystalline Ba₂V₂O₇ are reported and discussed by means of a Site Symmetry analysis.

28. Mitt. der Reihe Orthovanadate und verwandte Verbindungen. 27. Mitt.:E. J. Baran undM. E. Escobar, J. Phys. Chem. Solids, im Druck; 26. Mitt.:E. J. Baran, I. L. Botto, J. F. Ramos undP. J. Aymonino, Mh. Chem.109, 1139 (1978); 25. Mitt.:E. J. Baran, J. Mol. Struct.48, 441 (1978); 24. Mitt.:E. J. Baran undI. L. Botto, J. inorg. nucl. Chem.40, 1603, (1978); 23. Mitt.:M. E. Escobar undE. J. Baran, Z. Anorg. allg. Chem.,441, 273 (1978).     

Conformational analysis and electronic structure of monothiodiacetamide: Normal coordinate analysis and molecular orbital study

The infrared spectra of monothiodiacetamide (MTDA, CH₃CONHCSCH₃) and its N-deuterated compound in solution, solid state and at low temperature are measured. Normal coordinate analysis for the planar vibrations ofMTDA-d ₀ and –d ₁ have been performed for the two most probablecis-trans-CONHCS-or-CSNHCO-conformers using a simpleUrey-Bradley force function. The conformation ofMTDA derived from the vibrational spectra is supported by the all valence CNDO/2 molecular orbital method. The vibrational assignments and the electronic structure ofMTDA are also given.

---

Konformationsanalyse und elektronische Struktur von Monothiodiacetamid. Normalkoordinatenanalyse und MO-Studie

Zusammenfassung Das Infrarotspektrum von Monothiodiacetamid (MTDA, CH₃CONHCSCH₃) und der entsprechenden N-deuterierten Derivate wurde in Lösung, im Festzustand und bei tiefer Temperatur gemessen. Die Normalkoordinatenanalyse der möglichen planaren Konformeren wurde mittels einer einfachenUrey-Bradley-Funktion durchgeführt. Die dabei abgeleitete Konformation vonMTDA steht im Einklang mit einer semiempirischen quantenchemischen Rechnung (CNDO/2). Die Zuordnung der Schwingungen und die Elektronendichteverteilung inMTDA werden angegeben.

     

Hochdruckuntersuchungen zur Löslichkeit von Stickstoff in Wolfram

The paper reports investigations about the solubility of nitrogen in tungsten at nitrogen pressures up to 30 MPa (300 bar). The solubility of nitrogen obeysSieverts' law in the whole pressure range and can be represented by the equation logC _N=1/2 logp _{N 2}+4.0–9520/T (C _N in wt·ppm.p _{N 2} in bar,T in K).

     

Ab initio study of atropisomers of derivatives of 1,8-di-pyridine 9H-fluorene, dibenzo[b,d]furan, 9H-carbazole and dibenzo[b,d]thiophene

Ab initio calculation at HF/6-31G^* and MP2/6-31G^* levels of theory for geometry optimization of some syn- and anti-1,8-di-pyridine 9H-fluorene, dibenzo[b,d]furan, 9H-carbazole and Dibenzo[b,d]thiophene are reported. The rotational barrier energy, heat of formation and Gibbs energy are determined for the conversion of the anti-(syn) to the syn (anti)-isomers at 25 °C in the gas phase. The models are chosen as isomers of 9H-fluorene, dibenzo[b,d]furan, 9H-carbazole and dibenzo[b,d]thiophene as scaffold with pyridine as module. Results obtained show that (at equilibrium) for most of atropisomers the syn- is favored over the anti-isomer. Moreover, the ground state structures show that the modules are not parallel to each other but are tilted away in order to increase separation and there by minimize electrostatic repulsion. In atropisomers of 9H-carbazole the isomers are showing an attraction due to the presence of nitrogen atom. Influence of the position of nitrogen atom on the magnitude of the rotational barriers in these atropisomers is also studied.     

Thermodynamische Untersuchungen ann-Alkan/n-Alkin-Systemen

The vapour-liquid equilibrium data obtained from isobarict-x-measurements have been used for calculation of the group UNIFAC parameters and excess free enthalpyG ^E of binary mixturesn-alkanes with isomericn-alkynes. The UNIFAC model gives satisfactory predictions for the systems studied. The temperature dependence ofG ^E was estimated on the basis of the heats of mixing measured earlier. The influence of the position of triple bond in the molecules ofn-alkynes on the excess thermodynamic functions is considered.

     

Destruction ofB-polyfluorosubstitutedo-carboranes into anions ofB-fluorosubstitutednido-7,8-dicarbaundecaborates by the action of ethanolic alkali and amines

The destruction ofB-polyfluorosubstitutedo-carboranes by the action of ethanolic alkali and amines was studied. The destraction of trifluoro-o-carborane was found to occur regioselectively. The nature of the amine was shown to affect the stereochemistry of the destruction of trifluoro-o-carborane. The intermediate of the reaction of tetrafiuoro-o-carborane with diethylamine was detected.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1141–1145, June, 1995.     

MO-Berechnungen an Heterocyclen, 19. Mitt.: Zum Einfluß unterschiedlicher Orbitalexponenten für 2 s-und 2 p-STO auf die Sequenz der Orbitalenergien in CNDO-Typ-Rechnungen

CNDO-typ calculations based on a different choice of orbital exponents for 2s- and 2p-STO are able to reproduce almost exactly the order ofHartree-Fock orbital energies from high-accuracyab initio calculations. A uniform symmetry consideration for monocyclic molecules represents a useful method to correlate and compare the results. Some comments are given concerning the interpretation of UPS by means ofKoopmans theorem.

18. Mitt.:G. Kluge, undM. Scholz, Z. Chem., im Druck.     

The reactivity of N,N-dialkyl-N-(3-phenylsulfinyltetrahydrofuran-2-ylidene)ammonium bromide

trans-Stereoselective electrophilic cyclization of (2R*,SS*)-N, N-diisopropyl-2-phenylsulfinylpent-4-enamide under the action of bromine afforded (3R*,5S*, SS*)-N-(5-bromomethyl-3-phenylsulfinyltetrahydrofuran-2-ylidene)-N,N-diisopropylammonium bromide. Its transformations under the conditions of hydrolysis, dehydrobromination, and hydride reduction were studied. Dedicated to Academician V. A. Tartakovsky on the occasion of his 75th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1485–1490, August, 2007.