Alkylation of furan,thiophene, and pyrrole with furfuryl alcohol in the presence of the strongly acidic Amberlyst 15 sulfo cation-exchange resin

The corresponding 2-furylhetarylmethanes were obtained by the reaction of furan, thiophene, or pyrrole with furfuryl alcohol in the presence of the strongly acidic Amberlyst 15 cation-exchange resin in the H⁺ form. The alkylation of furan and thiophene takes place regiospecifically in the 2 position, whereas 2-furyl-2-pyrrolyl- and 2-furyl-3-pyrrolylmethane in a ratio of 6.21 are formed in the case of pyrrole.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 746–749, June, 1989.     

Extraktion des Rheniums als Tributylammoniumperrhenat

Zusammenfassung Durch Extraktion des Rheniums mit Methylenchlorid als [(C₄H₉)₃NH]ReO₄ im pH-Bereich 1–6 können Trennungen Re: Übergangsmetall= 110⁴ und Re^VIIMo^VI=160 erzielt werden. Durch Überführung des Rheniums in nichtwäßriger Phase in [(C₄H₉)₃NH]₃[ReO₂(SCN)₄] sind hierbei Rheniummengen ab 1,5 g bei 430 nm photometrisch bestimmbar.

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Summary Liquid-liquid extraction of rhenium as [(C₄H₉)₃NH]ReO₄ using dichloromethane within a pH-range of 1–6 enables separations Re: transition metal= 110⁴ (Re^VIIMo^VI=160). Photometric measurement (430 nm) of rhenium in non-aqueous solutions as [(C₄H₉)₃NH]₃[ReO₂(SCN)₄] allows the determination of 1.5 g of rhenium.

     

An EELS and EXELFS study of amorphous hydrogenated silicon carbide

A series of thin films of amorphous hydrogenated silicon carbide (a-SiCH) produced by RF plasma decomposition of propane and silane has been studied by electron energy-loss spectroscopy (EELS) and extended energy-loss fine structure (EXELFS) studies. The composition of the films has been determined by EELS and the nearest neighbour spacings have been determined by EXELFS. These results, along with the energy of the plasmon loss peaks, have been compared with the deposition conditions for each film. The results show that for a large gas ratio (C₃H₈/(C₃H₈+SiH₄)) the films have a high proportion of carbon and are similar to a-CH in structure, whereas those films prepared with Y = 0.4 or 0.5 have nearest neighbour spacings consistent with those for tetrahedrally bonded carbon. The films prepared with lowest Y have nearest neighbour spacings similar to those for amorphous silicon carbide. The results for a-SiCH have been compared with the results of EELS and EXELFS of CVD diamond films, amorphous carbon and amorphous silicon.     

Crystal Structure of Two Dimethyl 1,3-Thiazolidinedicarboxylates Obtained in Thermal [2 + 3]Cycloaddition of an Azomethine Ylide with 2,2,4,4-Tetramethyl-3-Thioxocyclobutanone

The crystal structures of dimethyl 2,2,4,4-tetramethyl-3-oxocyclobutane-1-spiro-5-3,4-diphenyl-(1,3)-thiazolidine-2,2-dicarboxylate, C₂₆H₂₉NO₅S for V, and dimethyl 3,4-diphenyl-5-isopropylidene-(1,3)-thiazolidine-2,2-dicarboxylate, C₂₂H₂₃NO₄S for VI, have been solved. The 1,3-thiazolidine ring of compound V has got twisted conformation, while in compound VI this ring adopts envelope. In both structures short inter- and intramolecular contacts were found, which can be recognized as hydrogen bonds.     

Micro reversed phase liquid chromatography of Cd-, Ni-, Zn-, Cu-, Co-, Hg-diethyldithiocarbamates at picogram level

Summary The use of micro reversed phase columns (Polygosil C18) for the separation of metal DDTC chelates was investigated and applied to drinking water analysis.Three different eluents have been tested [702010 (MeOH H₂OCHCl₃); 8020 (MeOHH₂O); 7030 (MeOHH₂O)] at flow rates of 7 to 28gml/min. Eluent composition showed strong influence onk of Co(DDTC)₂.The linear working curves fitted at least 3 decades with detection limit of 40–500 pg. Monitoring at _max instead of 254 nm decreases the detection limits. The consume of eluent is 10 to 20 times less than with analytical columnes.Results of micro LC have been compared with predictible data of theoretical considerations.

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Mikro-Umkehrphasen-Flüssigkeitschromatographie der Cd-, Ni-, Zn-, Cu-, Co-, Hg-Diethyldithiocarbamatchelate im Picogrammbereich

Zusammenfassung Die Anwendung von Mikro-RP-Säulen (Polygosil C18) für die Trennung von Metall-DDTC-Chelaten wurde untersucht und auf die Analyse von Trinkwasser angewendet. Drei verschiedene Eluentien [702010 (MeOH H₂OCHCl₃); 8020 (MeOHH₃O); 7030 (MeOHH₂O)] bei Fließraten von 7 bis 28gml/min wurden untersucht,k von Co(DDTC)₂ wird von der Eluenszusammensetzung erheblich beeinflußt. Der lineare Meßbereich betrug mindestens 3 Dekaden mit einer Nachweisgrenze von 40–500 pg, die durch Detektion bei _max statt bei 254 nm noch weiter gesenkt werden kann.Der Verbrauch an Eluens ist 10–20mal geringer als bei analytischen Säulen.Die Ergebnisse der Mikro-LC wurden anhand theoretischer Überlegungen mit den vorhersagbaren Daten verglichen.

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Presented in parts at 9th International Symposium on Microchemical Techniques, Amsterdam 1983.     

Phthalocyaninartige Bor-Komplexe

Zusammenfassung Aus Halogenboranen und Organohalogenboranen (RBX ₂R=C₆H₅, Cl, Br;X=F, Cl, Br) sowie aus Organoboranen oder Thioboranen entstehen mit Phthalodinitril Triisoindolo-[1,2,3-cd1,2,3-gh1,2,3-kl][2,3a,5,6a,8,9a,9b]-hexaazaboraphenalene von denen die B–Cl- und B–F-Verbindungen näher charakterisiert werden.Dekaboran(14), Diboran(6) oder Boranaddukte von Stickstoffbasen liefern hingegen mit Phthalodinitril metallfreies Phthalocyanin.

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Triisoindolo[1,2,3-cd1,2,3-gh1,2,3-kl][2,3a,5,6a,8,9a,9b]-hexa-azaboraphenalene

Triisoindolo[1,2,3-cd1,2,3-gh1,2,3-kl][2,3a,5,6a,8, 9a,9b]-hexaazaboraphenalenes are obtained from the reactions of haloboranes and organohaloboranes (RBX ₂R=C₆H₅, Cl, Br;X=F, Cl, Br) as well as from organoboranes or thioboranes with phthalodinitrile. The B–Cl and B–F compound have been characterized by analyses, i.r.-, u.v.- and mass-spectrometry.Diborane(6), dekaborane(14) and amine-boranes, however, upon reaction with phthalodinitrile lead to high yields of metal free phthalocyanine.

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Herrn Prof. Dr.M. Pailer zum 60. Geburtstag gewidmet.     

Substrate and Positional Selectivity in Electrophilic Substitution Reactions of Pyrrole, Furan, Thiophene, and Selenophene Derivatives

The relative reactivity (substrate selectivity) of five-membered heterocycles on electrophilic substitution (pyrrole >> furan > selenophene > thiophene) and their positional selectivity (furan > selenophene thiophene > pyrrole) are not consistent. The indicated differences in positional selectivity ( : ratios) of the parent heterocycles show up essentially in orientation on electrophilic substitution reactions of their derivatives and the corresponding benzannelated systems. It was shown that the positional selectivity was reduced in a sequence corresponding to the change in relative stability of the onium states of the elements (O⁺ < Se⁺ S⁺ < N⁺) and reflects the predominant role of the heteroatoms in stabilizing the -complexes formed on -substitution, in which the positive charge is distributed between the heteroatom and one -carbon atom (in -isom ers four atoms of the ring participate in delocalization of the charge). This interpretation was confirmed by quantum-chemical calculations carried out by the RHF/6-31G(d), MP2/6-31G(d)//RHF(6)-31G(d), and B3LYP/6-31G(d) ab initio methods.     

Tin(IV) complexes ofSchiff bases derived from salicylaldehyde and aminoalcohols

11 and 12 molar reactions of tin(IV) chloride with theSchiff bases, HO–C₆H₄CHNROH [where R=–(CH₂)₂–, –CH₂–, –CH(CH₃)–, –(CH₂)₃–, and –CH(C₂H₅)CH₂–] have been studied in different stoichiometric ratios and derivatives of the type SnCl₄(SBH₂) and SnCl₄(SBH₂)₂ (whereSBH₂ represents theSchiff base molecule) have been isolated. These have been characterised by elemental analysis, conductivity measurements and I.R. spectral studies.     

The electronic structures of urazole,pyrrole, and their ions. The σ-π separability problem

Ab initio all-electron LCGTO-SCF-MO calculations have been made on the 5-membered ring nitrogen heterocycles urazole (C₂H₃N₃O₂), pyrrole (C₄H₅N), and their ion radicals. Wavefunctions were obtained, population analyses made, and electron density contour maps drawn. The results show that for urazole considerable polarity develops in the bonds as a result of a large shift of charge towards the nitrogen atoms at the expense of the carbon and hydrogen atom -electrons with only little effect on the oxygen atom charges. In addition, it is concluded that the -electron approximation should be used with great caution for this type of molecule since the - separability conditions are not well satisfied.

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Zusammenfassung Für die Fünfring-Stickstoffheterocylen Urazol (C₂H₃N₃O₂), Pyrrol (C₄H₅N) und ihre Ionenradikale wurden ab initio Rechnungen nach der LCGTO-SCF-MO-Methode durchgeführt, wobei alle Elektronen berücksichtigt wurden. Die Besetzungszahlen wurden ermittelt und die Elektronendichten graphisch dargestellt. Die Rechnungen zeigen, daß für Urazol eine beträchtliche Polarität in den -Bindungen vorhanden ist. Der Grund dafür liegt in der starken Verschiebung der -Ladung in Richtung des Stickstoffatoms auf Kosten der -Elektronen des Kohlenstoffs und Wasserstoffs. Die -Ladungen am Sauerstoff werden kaum beeinflußt. Von einer -Elektronenapproximation für diese Art von Molekülen wird abgeraten, da die --Separationsbedingungen nur ungenügend erfüllt werden.

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Résumé Calculs ab-initio LCGTO-SCF-MO pour tous les électrons des hétérocycles pentagonaux: urazole (C₂H₃N₃O₂), pyrrole (C₄H₅N) et de leurs ions-radicaux. Après obtention des fonctions d'onde, l'analyse de population est affectuée et les cartes de densité électronique sont dréssées. Les résultats indiquent que l'urazole présente une forte polarité dans les liaisons sigma résultant d'un transfert de charge sigma vers les atomes d'azote aux dépens des atomes de carbone et d'hydrogène et en affectant peu les atomes d'oxygène. De plus, la séparabilité sigma pi n'est pas bien satisfaite dans ce type de molécule.

     

Detection and determination of benzophenone present in diphenylhydantoin sodium formulations and drug substance

Summary The detection of benzophenone in sodium diphenylhydantoin formulations and drug substance is carried out by thin-layer chromatography on silica gel 60 F using toluene/methanol/ethyl acetate/acetic acid/chloroform (802015105) or ethyl acetate/methanol/ammonium hydroxide (85105) as solvent and UV-light for visualizing. The determination is performed by measuring the absorption at 248 nm. The method is recommended for production monitoring.

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Nachweis und Bestimmung von Benzophenon in Natriumdiphenylhydantoin-Formulierungen und -Reinsubstanz

Zusammenfassung Der Nachweis erfolgt dünnschicht-chromatographisch auf Silicagel 60 F mit Toluol/Methanol/Äthylacetat/Essigsäure/Chloroform (802015105) oder Äthylacetat/Methanol/Ammoniak (85105) als Lösungsmittel und durch Sichtbarmachung mit UV-Licht. Die Bestimmung wird durch Absorptionsmessung bei 248 nm vorgenommen. Das Verfahren wird zur Produktionskontrolle empfohlen.

     

Dioxouranium(VI) complexes with potentially dibasic tridentate schiff base ligands. Characterization of the uranyl complexes of salicylaldehyde-2-hydroxyanil and its substituted derivatives

Summary Some 11, 23, and 12 uranyl complexes of salicylaldehyde-2-hydroxyanil (H₂SAP) and its substituted (3-methoxy-, 5-nitro-, 5-chloro- and 3,5-dichloro-) derivatives have been synthesized and characterized. The conductivity, i.r.,¹H n.m.r. and visible spectroscopic data allow discussion of the varying ligating behaviour of the potentially dibasic tridentate Schiff base ligands toward dioxouranium(VI).     

Molecular mass distribution of aliphatic and aromatic hydrocarbons obtained from CO and H2 in the presence of Fe catalysts

It has been demonstrated that together with C₁-C₆ aliphatic hydrocarbons up to 20% C₆-C₉ aromatic hydrocarbons are formed from a mixture of COH₂ (11) in the presence of 8.2% Fe-4.5% K/Al₂O₃. A new method for determining the parameter a in the Schultz-Flory equation has been proposed which is applicable to the synthesis of low molecular mass C₁-C₆ hydrocarbons. It has been shown that the mass fractions of aromatic hydrocarbons are higher than the values expected on the basis of a step-wise mechanism for growth of the hydrocarbon chain.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 40–44, January, 1991.     

Fixation and reduction of molecular nitrogen by [WH4(PC2H5Ph2)4] and [WH4(PCH3Ph2)4] in a γ-radiation field

Hydride complexes of W(IV) with dpep (diphenylethylphosphine) and dpmp (diphenylmethylphosphine) were irradiated in thf+C₆H₁₂(11) solutions, saturated with N₂+H₂(13). Radiation yields of hydrazine, ammonia and amines were evaluated. The mechanism of reduction of molecular nitrogen is discussed.     

Self-irradiation effects in plutonium/IV/ hydroxo phenyl acetate Pu/OH/3/C6H5CH2COO/ and plutonium/IV/ hydroxo α-naphthyl acetate Pu/OH/3/C10H7CH2COO/: EPR investigations

Self-irradiation effects due to -radiation in plutonium/IV/ hydroxo phenyl acetate, Pu/OH/₃/C₆H₅CH₂COO/ and hydroxo -naphthyl acetate, Pu/OH/₃/C₁₀H₇CH₂COO/ have been studied by EPR technique. OH and C₆H₅CH₂COO^. species are identified in the phenyl acetate while the C₁₀H₇CH₂COO^. species is detected in -naphthyl acetate. The values of the efficiency parameter, , determined for OH, C₆H₅CH₂COO^. and C₁₀H₇CH₂COO^. species are 0.8, 1.31 and 2.18, respectively. The results are interpreted on the basis of the thermal spikes associated with the alpha particle interaction with the lattice.     

Solvent and Temperature Dependence of 59Co NMR Chemical Shifts of Tris(acetylacetonato)cobaIt(III) and Tris(dipivaloylmethanato)cobalt(III)

Cobalt-59 NMR chemical shifts of Co(acac)₃, and Co(dpm)₃ (acac^– = acetylacetonate ion and dpm^– = dipivaloylmethanate ion) in 14 organic solvents, C₆H₁₄, C₆H₆, CH₂Cl₂, CHCl₃, CCl₄, CH₃CN, CH₃OH, C₂H₅OH, CH₃CH(OH)CH₃, (C₂H₅)₂O, (CH₃)₂CO, (CH₃)₂SO, (CH₃)₂NCHO and C₆H₅NO₂, were measured at five temperatures ranging from 289 to 329 K. The observed chemical shift (_obs) was linearly correlated to the maximum absorption wavelength in the visible spectra (_max) corresponding to the d-d electronic transition energy between the ground ¹A_1g and excited ¹T_1g states. The _obs-_max relation was explained by the ligand field theory. The temperature coefficients of _obs, of each complex showed a negative correlation with _obs. The _obs, of Co(acac)₃ decreased with the increasing electrophilic ability of the solvent (Mayer's acceptor number), whereas no tendency was observed in the case of Co(dpm)₃.     

Die Schwingungsspektren von Trimethylsilyl-alkyl-bzw.-phenyl-aminen

Zusammenfassung Die Infrarot- und die Raman-Spektren der Silylamine (CH₃)₃Si–NH–R (R=CH₃, C₂H₅ und C₆H₅) sowie der analogen N-deuterierten Verbindungen werden mitgeteilt und analysiert. Starke Kopplungen führen zu einer Mischung vonv SiN bei etwa 700 cm^–1 mit anderen Schwingungen des C₃Si–NHR-Skelettes.

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The Infrared and Raman spectra of the silylamino compounds (CH₃)₃Si–NH–R (R=CH₃, C₂H₅, and C₆H₅) and the analogous N-deuterated species are reported and assigned. The SiN stretching mode at about 700 cm^–1 is strongly coupled with other vibrations of the molecules.

     

Aktivierungsanalytische Bestimmung sehr kleiner Iridiumgehalte in Uranoxid

Zusammenfassung Es wird über die dünnschichtchromatographische Trennung und Reinheitsprüfung von 12 Naphthylaminmonosulfonsäuren berichtet. Für das Laufmittel n-Butanol-n-Propanol-Wasser-konz. Ammoniak (10541) werden die R_f-Werte ermittelt und ihre Standardabweichungen berechnet. Für die rechnerische Bestimmung der R_f-Werte aus den Dipolmomenten der Säuren wird eine quadratische Gleichung angegeben.

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Summary A report is presented on the thin-layer chromatographic separation and purity control of 12 naphthylaminemonosulphonic acids. R_f-values and standard deviations are determined for the solvent-mixture n-butanol-n-propanol-waterconc. ammonia (10541). A quadratic equation is given for the calculation of the R_f-values from the dipole moments of the acids.

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Für die Durchführung dieser Arbeit wurden dankenswerterweise Forschungsmittel aus dem ERP-Sondervermögen bereitgestellt.Dem Verbande der Chemischen Industrie und der Deutschen Forschungsgemeinschaft, die diese Arbeit unterstützt haben, danken wir bestens.     

The reactivity of complexed carbocycles,part 9. New cyclononatetraene cobalt complexes(1)

Summary Two new C₅H₅CoC₉H₁₀ cobalt complexes were shown to contain the cyclononatetraene ligand coordinated in a (3–6-)- and in a (1–25-6-) fashion. The former complex (2) rearranges at elevated temperatures to the latter (3) in a novel type of isomerisation. Complex (3) can be protonated with strong acids and hydrogenated at the uncomplexed double bonds. All compounds were characterised by¹³C n.m.r. spectroscopy.     

Catalytic synthesis of benzodithiophenes

Conclusions The reaction of p-diethylbenzene and H₂S on a chromium-containing oxide catalyst gives a thiophene analog of phenanthrene, namely, benzo[2,1-b3,4-b]dithiophene, and a thiophene analog of anthracene, namely, benzo[1,2-b4,5-b]dithiophene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2857–2859, December, 1988.