2,171 results on '"010402 general chemistry"'
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2. Über Reaktionen von N ‐Halogen ‐Stickstoff‐Schwefel‐Fluor‐ Verbindungen mit Hexafluorpropen und Bis(trifluormethyl)‐diazomethan
- Author
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Jürgen Varwig, Rüdiger Mews, and Oskar Glemser
- Subjects
Inorganic Chemistry ,chemistry.chemical_compound ,Trifluoromethyl ,chemistry ,010405 organic chemistry ,Diazomethane ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,3. Good health ,0104 chemical sciences - Abstract
Die radikalische Addition von CINSOF2 an Hexafluorpropen fuhrt zu F3 CCFEl-CF2 NSOF2 (1a) und F3CCF(NSOF2)CF2Cl (1 b); CIN(SO2F)2 ergibt nach einem vermutlich polaren Mechanismus ausschlieslich F3CCFClCF2N(SO2F)2 (2). Mit (CF3)2CN2 gelingt der Einschub von (CF3)2 unter Bildung von (CF3)2CClNSF 2 (3), (CF3)2CBrNSF2 (4), (CF3)2CClNSOF2 (5) und (CF3)2CClN(SO2F)2 (6). Reactions of N-Halogeno-Nitrogen-SWulphur-Fluorine Compounds wih Hexafluoropropene and Bis(trifluoromethyl)diazomethane The radical addition of ClNSOF2 to hexafluoropropene yields F3CCFClCF2NSOF2 (1a) and F3CCF(NSOF2)CF2Cl (1b); ClN(SO2F)2 reacts by a presumably polar mechanism to give exclusively F3CCFClCF2N(SO2F)2 (2). With (CF)2CN2 insertion of (CF3)2C into the Nhalogen bond of CINSF2, BrNSF2 CINSOF2 and ClN(SO2F)2 is possible with formation of (CF3)2 (6), respectively.
- Published
- 1974
3. The photolysis of trioses in aqueous solution
- Author
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Karl-Gerhard Seifert
- Subjects
Aqueous solution ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Drug Discovery ,Photodissociation ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences - Published
- 1974
4. The Formation of Cyclic Ethers by Intramolecular Addition and Substitution Processes in the Reaction of Olefinic Alcohols with Lead Tetraacetate. Part I. Preliminary communication
- Author
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Silvija Djokic-Mazinjanin, S. Konstantinovic, Nebojsa Pavlovic, Mihailo Lj. Mihailović, Jezdimir Stankovic, and Živorad Čeković
- Subjects
010405 organic chemistry ,Stereochemistry ,Chemistry ,Organic Chemistry ,Substitution (logic) ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Medicinal chemistry ,Catalysis ,0104 chemical sciences ,Inorganic Chemistry ,Lead (geology) ,Intramolecular force ,Drug Discovery ,Physical and Theoretical Chemistry - Published
- 1973
5. Homoallylic interaction in steroidal cyclodecenyl systems
- Author
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Ivan O. Juranić, Miroslav J. Gašić, Mihailo Lj. Mihailović, Milan M. Dabović, and Ljubinka Lorenc
- Subjects
010405 organic chemistry ,Chemistry ,Organic Chemistry ,Drug Discovery ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Medicinal chemistry ,0104 chemical sciences ,3. Good health - Abstract
Solvolysereaktionen an den steroidartigen Cyclodecenyl-Verbindungen (I) bzw. (II) werden in ihrer Kinetik sowie hinsichtlich der gebildeten Reaktionsprodukte diskutiert.
- Published
- 1974
6. Über Reaktionen des Trioxotrifluorcyclotrithiazens (Sulfanurfluorids) mit Aminen
- Author
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Teh‐Pei Lin, Rüdiger Mews, Oskar Glemser, and Hartmut Wagner
- Subjects
Inorganic Chemistry ,Aqueous solution ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Butyllithium ,Amine gas treating ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Adduct - Abstract
Je nach Wahl des Losungsmittels und der Reaktionstemperatur lassen sich in (NSO)3F3(1) mit sekundaren Aminen ein oder zwei Fluoratome unter Bildung von (NSO)3F2NR2 (2) oder (NSO)3F(NR2)2 (2) austauschen. Primare Amine reagieren zu (NSO)3F3· 3RNH2 [(NSO)3-F2NHR. RNH2 (3) + RNH3F]; die freien Amine (NSO)3F2NHR (4) entstehen bei der Umsetzung dieses Produktgemisches mit HCl. Die Addukte 3 sind in wasriger Losung in lonen dissoziiert, mit Ph4PCl fallen die entsprechenden Salze[Ph4P]+(NSO)3F2NR−(5) aus. Mit Butyllithium ergeben die Amine 4 die entsprechenden Lithiumverbindungen LiNR(NSO)3F2 (6). Reactions of Trioxotrifluorocyclotrithiazene (Sulfanuric Fluoride) with Amines Depending on the solvent one or two fluorine atoms in (NSO)3F3 (1) are exchanged by secondary amines under formation of (NSO)3F2NR2 (2) or (NOS)3F(NR2)2 (2′). Primary amines react to give (NSO)3F3·3RNH2 [(NSO3F 2NHR·RNH2 (3 ) + RNH3F]; the free amines (NSO)3F2NHR (4) are formed from this product mixture and HCl. In aqueous solution the adducts 3 are dissociated into ions, with Ph4PCl the appropriate salts [Ph4P]+[(NSO)3F2NR] −(5) are precipitated. From 4 and butyllithium LiNR (NSO)3F2 (6) is obtained.
- Published
- 1974
7. Mass transfer during gas evolution on the rotating double-ring electrode
- Author
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Branislav Ž. Nikolić, A.R. Despić, and I.V. Kadija
- Subjects
Chemistry ,Gas evolution reaction ,Mass transfer ,Electrode ,02 engineering and technology ,Atomic physics ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,01 natural sciences ,0104 chemical sciences ,Double ring - Published
- 1974
8. Umsetzungen von ungesättigten Organo-Stickstoffverbindungen mit Organoboranen bzw. Trichlorboran
- Author
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Anton Meller and W. Gerger
- Subjects
Trichloroborane ,chemistry.chemical_compound ,010405 organic chemistry ,Chemistry ,Methacrylonitrile ,Yield (chemistry) ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,3. Good health ,0104 chemical sciences ,Adduct - Abstract
While the reactions of N-diethylaminopropyne, methacrylonitrile and N-benzylidenemethylamine with organoboranes lead to addition of the latter across the multiple bond, methacrylonitrile and N-benzylidenemethylamine react with trichloroborane to yield adducts only.
- Published
- 1974
9. The phenyldiazenyl radical: An intermediate during the decomposition of phenylazotriphenylmethane
- Author
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Karl-Gerhard Seifert and F. Gerhart
- Subjects
010405 organic chemistry ,Computational chemistry ,Chemistry ,Organic Chemistry ,Drug Discovery ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Decomposition ,0104 chemical sciences - Published
- 1974
10. Anisotrope elektrische leitfähigkeit eines donator—akzeptor-komplexes aus Methylphenothiazin—Jod
- Author
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G. Dix
- Subjects
Crystallography ,Chemistry ,Orthorhombic crystal system ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials - Abstract
Aus N-Methylphenothiazin (MPT) und Jod werden drei verschiedene Charge-Transfer-Komplexe dargestellt: (MPT)2 · (J2)3, (MPT)2 · (J2)5 und (MPT)2 · (J2)7. Messungen der anisotropen elektrischen Leitfahigkeit am stabilsten Komplex (MPT)2 · (J2)3, orthorhombisch) wurden im Temperaturbereich von −180°C bis +40°C durchgefuhrt. Bei 23°C betragen die Hauptleitfahigkeiten 95; 0,96, und 0,022 (Ωcm)−1 (Anisotropieverhaltnis 4300:43:1). Der Temperaturverlauf ist fur alle drei Kristallrichtungen ahnlich. Three different charge transfer complexes were prepared from N-methyl-phenothiazine (MPT) and iodine: (MPT)2 · (J2)3, (MPT)2 · (J2)5, and (MPT)2 · (J2)7. Measurements of the anisotropic electric conductivity of the most stable complex (MPT)2) · (J2)3, orthorhombic) were performed in the temperature range from −180°C to +40°C. The principal conductivities are at 23°C: 95, 0.96, and 0.022 (Ωcm)−1 (anisotropy ratio 4300:43:1). The temperature behaviour is similar in the three crystal directions.
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- 1974
11. Criteria for the determination of the stereochemistry of steroidal indolizidines
- Author
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V.M. Kolb and M. Stefanović
- Subjects
Indolizidines ,indolizidines ,010405 organic chemistry ,Stereochemistry ,Chemistry ,Organic Chemistry ,stereochemistry ,chemistry.chemical_element ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Nitrogen ,3. Good health ,0104 chemical sciences ,chemistry.chemical_compound ,Reaction rate constant ,Solanum Alkaloids ,Drug Discovery ,Mass spectrum ,Organic chemistry ,steroidal indolizidines ,Structural unit ,Methyl iodide - Abstract
E/F-Indolizidine steroids, which represent a structural unit of Solanum alkaloids, have been synthesized and used to evaluate criteria (IR—Bohlmann bands,1a-c —hydrogenbond,2a-e NMR,3a-c mass spectra,4 kinetic studies of quaternization with methyl iodide,5a,b oxidation with mercuric acetate6) for the determination of the stereochemistry of these systems. It was found that the most reliable method is the measurement of the rate constants of quaternization of the bridgehead nitrogen with methyliodide.
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- 1974
12. Umsetzungen von Metall- und Metalloidverbindungen mit mehrfunktionellen Molek�len, 2. Mitt.: Reaktionsprodukte von Aminobenzonitrilen mit Halogenboranen
- Author
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Anton Meller, Walter Maringgele, and G. Maresch
- Subjects
Hydrogen ,Nitrile ,010405 organic chemistry ,Chemistry ,chemistry.chemical_element ,Halide ,General Chemistry ,010402 general chemistry ,Ring (chemistry) ,01 natural sciences ,0104 chemical sciences ,3. Good health ,Hydrogen halide ,chemistry.chemical_compound ,Yield (chemistry) ,Polymer chemistry - Abstract
Both 4-aminobenzonitrile and 3-aminobenzonitrile react with halogenoboranes to yield mainly the corresponding amine-halogenoboranes and further products derived from the latter by elimination of hydrogen halide. In contrast, reaction between halogenoboranes and 2-aminobenzonitrile leads to insertion of the nitrile group into one of the B-halogen bonds. Derivatives of the 1.3.2-diazaboranaphthalene ring result from reactions of the insertion products with the amino group with or without elimination of hydrogen halides.
- Published
- 1974
13. CIDNP‐Untersuchung des Photoreduktionssystems Aceton/Isopropylalkohol
- Author
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Karl-Gerhard Seifert
- Subjects
010405 organic chemistry ,Chemistry ,CIDNP ,Radical ,Isopropyl alcohol ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Medicinal chemistry ,Uncorrelated ,3. Good health ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Acetone - Abstract
Das Photoreduktionssystem Aceton/Isopropylakohol wurde mit partiell deuterierten Komponenten mit Hilfe der CIDNP-Spektroskopie untersucht. Auf sehr einfache Weise konnte das CIDNP-Spektrum von Propen-2-ol erhalten werden. Die entstehenden 2-Hydroxypropyl-Radikale bilden unkorelierte Radikalpaare, die in die Ausgangsverbindungen disproportionieren. A CIDNP Study of the Photoreduction System Acetone/Isopropyl Alcohol The photoreduction system acetone/isopropyl alcohol has been studied by means of CIDNP spectroscopy. Partially deuterated components were used. The CIDNP spectrum of propen-2-ol was obtained by a simple method and it is shown, that the generated 2-hydroxypropyl radicals form uncorrelated radical pairs, which disproportionate into the starting material.
- Published
- 1974
14. [Untitled]
- Author
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Hannu Sairanen, J. Johan Lindberg, and Väinö A. Erä
- Subjects
Chemistry ,Substituent ,Infrared spectroscopy ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensation reaction ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Absorbance ,chemistry.chemical_compound ,Polymer chemistry ,Phenol ,General Materials Science ,Guaiacol ,0210 nano-technology - Abstract
The process of novolak-type of phenol-formaldehyde and guaiacol-formaldehyde resins was studied by infrared spectroscopy. It was shown that in phenol-formaldehyde resins monosubstitution and disubstitution increases in the condensation reaction reaching a maximum with Mn value of 250. The increase of 2,4,6-substitution was observed at higher molecular weights. In the guaiacol resins all substituent groups indicate a maximum absorbance at Mn value of 330–350. Der Bildungsprozes von Phenol/Formaldehyd- und Guajacol/Formaldehyd-Harzen wurde mit Hilfe der IR-Spektroskopie studiert. Es wurde gezeigt, das wahrend der Kondensationsreaktion Monosubstitution und Disubstitution zunehmen und ein Maximum beim Mn-Wert von 250 erreichen. Zunehmende 2,4,6-Substitution wurde bei hoheren Molekulargewichten beobachtet. In den Guajacolharzen zeigen alle Substitutionstypen ein Maximum beim Mn-Wert von 330–350.
- Published
- 1974
15. Dispiro[2.0.2.4]deca‐7,9‐dien und Spiro[2.5]octa‐4,6‐dien: Chemische Umsetzungen, thermische und photochemische Umlagerungen
- Author
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Armin de Meijere
- Subjects
Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,010405 organic chemistry ,Stereochemistry ,Thermal decomposition ,010402 general chemistry ,01 natural sciences ,Ethylbenzene ,Cycloaddition ,0104 chemical sciences ,3. Good health - Abstract
Einige [4 + 2]-Cycloadditionen der Titelverbindungen 1 und 2 werden untersucht; in allen Fallen beobachtet man normale Addition an das 1,3-Diensystem. Mit Sauren liefert 1 bei erhohter Temperatur unter Offnung beider Cyclopropanringe o-Athylstyrol (16) und Derivate des 2-(o-Athlphenyl)athans. Die Thermolyse von 1 oberhalb 120°C fuhrt zu 16 und Tetralin (20). Die thermische Umlagerung von 2 zu Athylbenzol erfordert hohere Temperaturen. Photochemisch bilden sich aus 1 sowohl bei direkter als auch bei sensibilisierter Anregung 16 und 20 im Verhaltnis von ca. 2:1. Mogliche Mechanismen dieser Umlagerungen werden diskutiert. Dispiro[2.0.2.4]deca-7,9-diene and Spiro[2.5]octa-4,6-diene: Their Chemical Reactions, Thermal and Photochemical Rearrangements Some [4 + 2]cycloaddition reactions of the title compounds 1 and 2 have been investigated. In all cases normal addition onto the 1,3-diene system is observed. 1 in the presence of proton acids at elevated temperatures yields o-ethylstyrene (16) and derivatives of 2-(o-ethylphenyl)ethane. The thermolysis of 1 above 120°C gives a mixture of 16 and tetraline (20). Higher temperatures are required for the thermal rearrangement of 2 to ethylbenzene. photo-chemically 1 yields a mixture of 16 and 20 in a ratio of about 2:1 both on direct and sensitized excitation. Possible mechanisms for these rearrangements are discussed.
- Published
- 1974
16. Reaktionen des 3,3‐Dichlor‐1,5,2,4,6,3‐dithiatriazaphosphor(V)‐in‐ S , S ′‐bis(oxidfluorids), eines cyclischen Phosphornitrilsulfanurhalogenids
- Author
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Uwe Klingebiel, Walter Heider, Teh‐Pei Lin, and Oskar Glemser
- Subjects
010405 organic chemistry ,Chemistry ,Oxide ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,3. Good health ,0104 chemical sciences ,Inorganic Chemistry ,Ammonia ,chemistry.chemical_compound ,Molar ratio ,Yield (chemistry) ,Fluoride - Abstract
(NSOF)2NPCl21 reagiert mit Ammoniak im Molverhaltnis 1:2 zu 1, mit Silylaminen (CH3)3SiNHR (RCH3, C2H5) im Molverhaltnis 1:1 zu 2 und 3, mit (CH3)3SiNR2 (RCH3, C2H5) zu 4 und 5. Schlieslich konnten aus (NSOF)2NPCl 2 und Disilylaminen [(CH3)3Si]2NR (RH, CH3, C2H5) die Verbindungen 6, 7 und 8 isoliert werden. Die IR-, Massen- und 1H-, 19F-und 31P-NMR-Spektren dieser Verbindungen werden mitgeteilt. Reactions of 3,3-Dichloro-1,5,2,4,6,3-dithiatriazaphosphor(V)in-S,S′-bis(oxide fluoride), of a Cyclic Phosphornitrilsulfanur Halogenide (NSOF)2NPCl2 reacts with ammonia in a molar ratio of 1:2 to give 1, with silylamines (CH3)3SiNHR (RCH3, C2H5) in a molar ratio 1:1 to yield 2 and 3, and with (CH3)3SiNR2 (RCH3, C2H5) to form 4 and 5. The reaction of (NSOF)2NPCl2 with disilylamines [(CH3)3Si]2NR (RH, CH3, C2H5) yields the compounds 6, 7, and 8. The i.r., mass, 1H, 19F, and 31P n.m.r. spectra of the above mentioned compounds are reported.
- Published
- 1974
17. Dispiro[2.0.2.4] deca‐7,9‐dien und Vergleichsverbindungen: Darstellung, UV‐, NMR‐ und Photoelektronen‐spektroskopische Untersuchungen
- Author
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Armin de Meijere
- Subjects
Bromine ,010405 organic chemistry ,Stereochemistry ,Chemical shift ,Electron delocalization ,chemistry.chemical_element ,010402 general chemistry ,Ring (chemistry) ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Bathochromic shift ,Octane - Abstract
Dispiro[2.0.2.4] deca-7,9-dien (4) und Spiro[2.5]octa-4,6-dien (5) lassen sich aus den entsprechenden Monoolefinen 6 bzw. 10 durch Bromierung und anschliesende Dehydrobromierung gewinnen. Die UV-Absorptionen von 5 und 4 mit λmax = 269 nm (log e = 3.4) bzw. 284 nm (3.7) sind bathochrom verschoben gegenuber denjenigen des 1,3-Cyclohexadiens. Aus einer Analyse der Chemischen Verschiebungen und H,H-Kopplungskonstanten der olefinischen Protonen im 1H-NMR-Spektrum von 4 ist zu schliesen, das 4 kein cyclisch delokalisiertes Elektronensystem enthalt. Der Sechsring in 4 ist nur wenig starker eingeebnet als derjenige im 1,3-Cyclohexadien. Anhand der Photoelektronen-Spektren von 4, 5 sowie Spiro[2.5]octan (13), Spiro[2.5]oct-4-en (15), Dispiro[2.0.2.4]decan (14) und Dispiro[2.0.2.4]dec-7-en (16) wird der Effekt der Wechselwirkung zwischen π-Orbitalen und Cyclopropyl-Walsh-Orbitalen aufgezeigt; fur die jeweils ersten Banden in den PE-Spektren dieser Verbindungen wird eine Zuordnung vorgeschlagen. Dispiro[2.0.2.4]deca-7,9-diene and Related Model Compounds: Synthesis, U.V, N.M.R, and Photoelectron-Spectroscopic Investigations Dispiro[2.0.2.4]deca-7,9-diene (4) and spiro[2.5]octa-4,6–diene (5 can be obtained from the corresponding monoolefins 6 and 10, respectively, by bromine addition and subsequent dehydrobromination. The u. v. spectra of 5 and 4 with λmax = 269 nm (log e = 3.4) and 284 nm (3.7), respectively, show bathochromic shifts of their longest wavelength bands as compared to 1,3-cyclohexadiene. An analysis of the 1H n. m. r. chemical shifts and H, H-coupling constants for the olefinic protons in 4 indicates that there is no cyclic electron delocalization in this ring system. The six-membered ring in 4 is only slightly flatter than the one in 1,3- cyclohexadiene. The photoelectron spectroscopic data of 4, 5, spiro[2.5]octane (13), spiro[2.5]oct-4-ene (15), dispiro[2.0.2.4]decane (14), and dispiro[2.0.2.4]dec-7-ene (16) demonstrate the effect of the interaction between π-orbitals and cyclopropyl Walsh-orbitals; an assignment for the first bands in the p. e. spectra of these compounds is proposed.
- Published
- 1974
18. Ion implantation effects in 'cosmic' dust grains
- Author
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Yves Langevin, B. Jouffrey, R. Meunier, M. Maurette, C. Jouret, J. P. Bibring, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
- Subjects
chemistry.chemical_classification ,Physics ,Alpha particle ,Astrophysics ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Ion ,Interstellar medium ,Geophysics ,Ion implantation ,Interplanetary dust cloud ,chemistry ,13. Climate action ,Space and Planetary Science ,Geochemistry and Petrology ,Chemical physics ,Sputtering ,0103 physical sciences ,Earth and Planetary Sciences (miscellaneous) ,Compounds of carbon ,[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det] ,010303 astronomy & astrophysics ,Cosmic dust - Abstract
Cosmic dust grains, whatever their origin may be, have probably suffered a complex sequence of events including exposure to high doses of low-energy nuclear particles and cycles of turbulent motions. High-voltage electron microscope observations of micron-sized grains either naturally exposed to space environmental parameters on the lunar surface or artificially subjected to space simulated conditions strongly suggest that such events could drastically modify the mineralogical composition of the grains and considerably ease their aggregation during collisions at low speeds. Furthermore, combined mass spectrometer and ionic analyzer studies show that small carbon compounds can be both synthesized during the implantation of a mixture of low-energy D, C, N ions in various solids and released in space by ion sputtering.
- Published
- 1974
19. ?-Metalated Isocyanides in Organic Synthesis. New synthetic methods (6)
- Author
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Dieter Hoppe
- Subjects
010405 organic chemistry ,Chemistry ,Isocyanide ,chemistry.chemical_element ,General Medicine ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,Nucleophile ,Intramolecular force ,Electrophile ,Organic chemistry ,Organic synthesis ,Carbon - Abstract
α-Alkali-metalated isocyanides, which can be obtained from isocyanides and bases, can be used for nucleophilic introduction of (masked) α-aminoalkyl groups. Intramolecular ring-closure may then follow if a nucleophile combines at the electron sextet of the isocyanide carbon. Treatment of α-alkali-metalated isocyanides with electrophilic agents permits rapid and efficient synthesis of, inter alia, 2- and 3-amino alcohols, straight-chain, branched, and β-functional α-amino acids, olefins, vinyl isocyanides, and of a large number of mainly five-, but also six- and seven-membered aza-, diaza-, oxa-aza-, and thia-aza heterocycles.
- Published
- 1974
20. Molecular photodissociation
- Author
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Shaul Mukamel and Joshua Jortner
- Subjects
010304 chemical physics ,0103 physical sciences ,General Physics and Astronomy ,Physical and Theoretical Chemistry ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences - Published
- 1974
21. Mise au point : détermination à partir de la spectroscopie ENDOR de couplages hyperfins dans un radical libre créé dans un cristal organique
- Author
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P. Gloux
- Subjects
Physics ,010304 chemical physics ,[PHYS.HIST]Physics [physics]/Physics archives ,0103 physical sciences ,organic crystals ,crystal hyperfine field interactions ,free radicals ,ENDOR ,010402 general chemistry ,01 natural sciences ,hyperfine couplings ,0104 chemical sciences - Abstract
On discute de la détermination par ENDOR des couplages hyperfins pour des radicaux libres créés dans des cristaux organiques. L'exposé est centré sur le cas du couplage hyperfin avec le proton puisque c'est le cas le plus fréquent. Les diverses ambiguïtés que l'on rencontre dans l'identification et le calcul des couplages sont étudiées en détail.
- Published
- 1974
22. [Untitled]
- Author
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Väinö A. Erä
- Subjects
chemistry.chemical_classification ,chemistry ,Polymer chemistry ,Isothermal crystallization ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,01 natural sciences ,0104 chemical sciences - Abstract
A series of suspension chlorinated and chlorosulfonated polyethylenes (CPE and CSPE resp.) of varying chlorine contents were investigated. The s- and γ-relaxation processes are related to motions of CH2CHClCH2 and CH2 units in the chains of CPE and CSPE polymers, respectively. In isothermal crystallization, the fine structures of the polymers change gradually, as is shown by the variation in the pattern of the DSC curve and the shift of the melting peak. Eine Reihe von suspensionschlorierten und sulfochlorierten Polyathylene (CPE bzw. CSPE) verschiedenen Chlorgehalts wurde untersucht. Die s- und γ-Relaxationsprozesse sind mit Bewegungen von CH2CHCICH2 und CH2-Gruppen in den Ketten der CPE- bzw. CSPE-Polymeren verkniipft. Wahrend der isothermischen Kristallisation erfolgt eine graduelle Veranderung der Feinstruktur der Polymeren, was durch die Variation der Form der DSC-Kurve und durch eine Verschiebung des Schmelzpunkts angezeigt wird.
- Published
- 1974
23. Zur lokalisierung funktioneller gruppen mit hilfe der massenspektrometrie—XI
- Author
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E. Zietz and Gerhard Spiteller
- Subjects
010405 organic chemistry ,Chemistry ,Stereochemistry ,Organic Chemistry ,Drug Discovery ,010402 general chemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences - Abstract
Zusammenfassung Massenspektrometrische Abbaureaktionen von Steroiden mit Hydroxylgruppen in den Stellungen 12 und 17β sind stark abhangig von der Konfiguration der 12-standigen OH-Gruppe: In Verbindungen mit einer α-konfigurierten Hydroxylgruppe in der Stellung 12 abstrahiert diese den 17α-standigen Wasserstoff und wird dann als H 2 O eliminiert. In der Folge wird ein Methylradikal abgespalten. In den Isomeren mit 12β-standiger Hydroxylgruppe hingegen ist diese Reaktion nicht moglich. Es dominiert hier der Verlust der Kohlenstoffatome 15–17, bzw. die Bildung eines Ions unter Verlust eines zweiten Wassermolekuls. In 17-Ketosteroiden mit einer 12-standigen Hydroxylgruppe werden bei Vorliegen eines trans -verknupften A/B-Ringsystems bevorzugt Schlusselionen der Masse 97 sowte M-44 und M-74-Ionen gebildet, wahrend bei cis -Verknupfung des A/B-Ringsystems weniger typische Abbaureaktionen eintreten.
- Published
- 1974
24. The stereochemistry of fragmentation products formed in the lead tetraacetate and related oxidations of alcohols. Part. I. ?-fragmentation ofcis-andtrans-4-t-Butylcyclohexanemethanol
- Author
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Živorad Čeković, Jovan Bosnjak, and Mihailo Lj. Mihailović
- Subjects
Steric effects ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Organic Chemistry ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Chloride ,Heterolysis ,Catalysis ,0104 chemical sciences ,Homolysis ,Inorganic Chemistry ,Reagent ,Drug Discovery ,medicine ,Physical and Theoretical Chemistry ,Fragmentation (cell biology) ,Oxidative decarboxylation ,Cis–trans isomerism ,medicine.drug - Abstract
The stereochemistry of β-fragmentation products formed in the oxidation of cis-and trans-4-t-butylcyclohexaanemethanol with lead tetraacetate and with lead tetraacetate-metal chloride combinations, under various reaction conditions, has been investigated, and the results compared with those obtained, under similar conditions, in the oxidative decarboxylation of cis-and trans-4-t-butylcyclohexanecarboxylic acid with the same reagents. It was found that all four substrates afford, under comparable conditions, identical cis-trans proportions of the respective fragmentation products, and that, therefore, so far as steric course is concerned, both the initial homolytic and subsequent heterolytic processes involved in the lead tetraacetate fragmentation reaction are independent of the nature and configuration of the starting material.
- Published
- 1974
25. Natural bismuth vanadate from the Mutala pegmatite area, Mozambique
- Author
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Martti Lehtinen, Jaakko Siivola, O. v. Knorring, Pentti Rehtijärvi, and Th. G. Sahama
- Subjects
Mineralogy ,010402 general chemistry ,010502 geochemistry & geophysics ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Crystallography ,Geophysics ,chemistry ,Geochemistry and Petrology ,Bismutite ,Scheelite ,Bismuth vanadate ,Orthorhombic crystal system ,Crystal habit ,Crystal twinning ,Pegmatite ,Geology ,0105 earth and related environmental sciences ,Monoclinic crystal system - Abstract
Bismuth vanadate (microprobe test) in varying shades of orange color and in well developed crystals (averaging 0.2 mm in size) occurs in bismutite in the Mutala granite pegmatite area, district of Zambezia, Mozambique. Two modifications of BiVO4were identified. An orthorhombic form is identical with pucherite and shows a0 = 5.336 A, b0 = 5.053 A, c0 = 12.021 A. The crystal habit ranges from platy to stout prismatic. The X-ray powder pattern of the monoclinic form matches that of the synthetic monoclinic Bi-orthovanadate with a0 = 5.205 A, b0 = 11.718 A, c0 = 5.098 A, β = 90° 25′. The crystal habit resembles that of a pyramidal scheelite crystal with the b-axis corresponding to the scheelite c-axis. Multiple twinning is seen on (101), in some instances with a composition plane (010).
- Published
- 1973
26. Gordon Research Conferences
- Author
-
A M, Cruickshank
- Subjects
0106 biological sciences ,0301 basic medicine ,0303 health sciences ,Multidisciplinary ,010304 chemical physics ,05 social sciences ,010501 environmental sciences ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,03 medical and health sciences ,030104 developmental biology ,0103 physical sciences ,0509 other social sciences ,050904 information & library sciences ,0105 earth and related environmental sciences ,010606 plant biology & botany ,030304 developmental biology - Published
- 1974
27. Field desorption mass spectrometry in the analysis of a steroid conjugate, estriol-16α-glucuronid
- Author
-
Matti J. Tikkanen, B. Soltmann, and Herman Adlercreutz
- Subjects
medicine.medical_treatment ,Sodium ,Potassium ,chemistry.chemical_element ,Glucuronates ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Mass Spectrometry ,Steroid ,Ion ,Metal ,chemistry.chemical_compound ,Endocrinology ,Pregnancy ,Methods ,medicine ,Humans ,Chromatography ,Estriol ,Chemistry ,010401 analytical chemistry ,Polyatomic ion ,Chromatography, Ion Exchange ,Glucuronic acid ,0104 chemical sciences ,Molecular Weight ,Evaluation Studies as Topic ,visual_art ,Chromatography, Gel ,visual_art.visual_art_medium ,Female ,Conjugate - Abstract
Field desorption mass spectrometry was used for the first time in the analysis of a steroid conjugate, the estriol-16α-glucuronide, isolated from pregnancy urine. Two reference compounds were also investigated. The molecular ion peak of the underivatized conjugate was obtained indicating that the molecular weight of such compounds can easily be determined. Variation in the solvent composition causes some variation in the spectra obtained and complex ion formation was noted. Because of the ubiquity of sodium and potassium, ions containing these metallic elements and representing the sodium and potassium salts of the steroid glucuronic acid are seen in the spectra.
- Published
- 1974
28. Anodische Dimerisierung von Enoläthern
- Author
-
Dietrich Koch, E. Steckhan, and Hans J. Schäfer
- Subjects
chemistry.chemical_classification ,Graphite anode ,010405 organic chemistry ,Radical ,010402 general chemistry ,Sodium perchlorate ,Electrochemistry ,01 natural sciences ,Enol ,0104 chemical sciences ,3. Good health ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Polymer chemistry ,Enol ether ,Methanol ,Alkyl - Abstract
Acht Enolather werden in einer ungeteilten Zelle an einer Graphitanode in Methanol/2,6- Lutidin/Natriumperchlorat in Ausbeuten zwischen 30 und 60% zu Acetalen von 1,4-Dicarbonylverbindungen dimerisiert. Die voltammetrischen Daten: elektrochemische Reaktion 1. Ordnung bezuglich Enolather, elektrochemische Reaktion nullter Ordnung bezuglich Methanol und nα = 1 sowie die Schwanz-Schwanz-Verknupfung der Enolather legen einen Reaktionsverlauf uber Enolather-Radikalkationen nahe. Die Kupplung uber Methoxy-Radikale ist unwahrscheinlich. Die Halbwellenpotentiale der Enolather sind uber E1/2 = 1.72 + A (V gegen Ag/AgCl) abschatzbar, wobei A = − 0.3 bzw. −0.45 V fur Substitution von H gegen ein bzw. zwei Alkylgruppen und + 0.4 V fur Ersatz von H gegen CO2At betragt. Anodic Dimerization of Enol Ethers Eight enol ethers are dimerized in an undivided cell at a graphite anode in methanol/2,6-lutidine/sodium perchlorate to acetals of 1,4-dicarbonyl compounds in 30 to 60% yields. The electrochemical reaction is first order with respect to enol ether and zero order with respect to methanol and nα = 1. These data as well as the tail to tail coupling of the enol ethers indicate a reaction via radical cations of the enol ethers. Dimerization via methoxy radicals is improbable. The half wave potentials of the enol ethers have been estimated to be E1/2 = 1.72 + A (V versus Ag/AgCl), with A being −0.3 or −0.45 V for substitution of H by one or two alkyl groups, respectively, and + 0.4 V for substitution of H by CO2Et.
- Published
- 1974
29. Zur lokalisierung funktioneller gruppen in steroiden mit hilfe der massenspektrometrie—XII
- Author
-
Gerhard Spiteller and E. Zietz
- Subjects
010405 organic chemistry ,Stereochemistry ,Chemistry ,Organic Chemistry ,Drug Discovery ,010402 general chemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences - Abstract
Zusammenfassung Massenspektren von Steroiden mit Carbonylfunktionen in den Stellungen 12 und 17 sind durch das Auftreten von Schlusselionen der Masse 110 sowie M-28 (MCO) gekennzeichnet.
- Published
- 1974
30. Behavior of sodium tungsten bronze electrode in alkaline solutions
- Author
-
D. S. Ovcin, M.V. Vojnovic, N.D. Pavlović, and D. B. Sepa
- Subjects
Sodium tungsten bronze ,Sodium ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,Tungsten ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Nitrogen ,0104 chemical sciences ,Anode ,chemistry.chemical_compound ,chemistry ,Electrode ,engineering ,Surface layer ,Bronze ,0210 nano-technology - Abstract
Summary Sodium tungsten bronze electrode of the composition x=0.80 was studied, using steady state potentiostatic amd galvanostatic methods, in nitrogen saturated alkaline solutions of different pH values and different WO42− concentrations. It is proposed that a sodium deficient, hydrated, tungsten oxide-like layer is spontaneously formed at the surface of the bronze in alkaline solutions. The anodic process is the oxidation of this surface layer with the WO42− anion as the final product. Possible cathodic processes are discussed.
- Published
- 1974
31. Competing concerted and radical mechanisms I: The 2-alkoxyquinoline-n-oxide rearrangement
- Author
-
L. Wilde and F. Gerhart
- Subjects
chemistry.chemical_compound ,chemistry ,010405 organic chemistry ,Organic Chemistry ,Drug Discovery ,Oxide ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences - Published
- 1974
32. Electrochemical syntheses of heterocyclic compounds—I
- Author
-
Zivorad Cekovic, M. Lacan, and I. Tabakovic
- Subjects
Nucleophilic addition ,010405 organic chemistry ,Chemistry ,Anodic oxidation ,Organic Chemistry ,Disproportionation ,010402 general chemistry ,Electrochemistry ,Ring (chemistry) ,Photochemistry ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,0104 chemical sciences ,Dication ,Coulometry ,chemistry.chemical_compound ,Drug Discovery ,Formazan - Abstract
A novel way of tetrazolium salt preparation by anodic oxidation of formazan is described. Products were obtained in good yields and purity. The mechanism of oxidation was deduced from voltammetric data and by coulometry at controlled potential. Two main pathways were identified, one leading via radical-cation and dication to ring closure by nucleophilic addition, the other involves disproportionation of the radical-cation to dication plus original formazan. Oxidability of differently substituted 3-aroyl-1,5-diarylformazans depends on the electron-withdrawing powers of substituted rings.
- Published
- 1974
33. Isolation and characterization of the cyanogen bromide fragments from human lactotransferrin
- Author
-
Jean Montreuil, Joël Mazurier, Geneviève Spik, Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Université de Lille-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
MESH: Amino Acids ,Dansyl Compounds ,Lactoglobulins ,MESH: Amino Acid Sequence ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,MESH: Spectrophotometry, Ultraviolet ,Structural Biology ,Cyanogen Bromide ,Amino Acids ,MESH: Peptide Fragments ,ComputingMilieux_MISCELLANEOUS ,MESH: Glucosamine ,Glucosamine ,0303 health sciences ,MESH: Milk, Human ,Chemistry ,MESH: Molecular Weight ,MESH: Chromatography, Gas ,MESH: Chromatography, Gel ,Chromatography, Ion Exchange ,3. Good health ,Lactotransferrin ,MESH: Mannose ,Chromatography, Gel ,MESH: Lactoglobulins ,Female ,Cyanogen bromide ,MESH: Galactose ,Chromatography, Gas ,Biophysics ,010402 general chemistry ,MESH: Sialic Acids ,03 medical and health sciences ,Genetics ,Humans ,[SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology ,Amino Acid Sequence ,MESH: Fucose ,MESH: Electrophoresis, Disc ,Molecular Biology ,Fucose ,MESH: Dansyl Compounds ,030304 developmental biology ,MESH: Humans ,Chromatography ,Milk, Human ,Galactose ,Cell Biology ,Electrophoresis, Disc ,MESH: Chromatography, Ion Exchange ,Peptide Fragments ,MESH: Lactoferrin ,MESH: Cyanogen Bromide ,0104 chemical sciences ,Molecular Weight ,Lactoferrin ,Sialic Acids ,Spectrophotometry, Ultraviolet ,Mannose ,MESH: Female - Abstract
International audience
- Published
- 1974
34. Spin probe studies on molecular motions of 2,6-disubstituted poly(phenylene oxides) near glass transition
- Author
-
A. Savolainen and P. Törmälä
- Subjects
Spin probe ,Crystallography ,Materials science ,Phenylene ,General Engineering ,Molecular motion ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,Glass transition ,01 natural sciences ,0104 chemical sciences - Published
- 1974
35. α-Metallierte Isocyanide in der Organischen Synthese
- Author
-
Dieter Hoppe
- Subjects
010405 organic chemistry ,General Medicine ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences - Abstract
α-Alkalimetallierte Isocyanide – zuganglich aus Isocyaniden und Basen — gestatten die nucleophile Einfuhrung von (maskierten) α-Aminoalkylgruppen. Ein intramolekularer Ringschlus kann folgen, wenn sich ein Nucleophil in das Elektronensextett des Isocyanid-Kohlenstoffs einlagert. Die Umsetzung der α-alkalimetallierten Isocyanide mit Elektrophilen gestattet die schnelle und ergiebige Synthese u. a. von 2- und 3-Aminoalkoholen, geradkettigen, verzweigten sowie β-funktionellen α-Aminosauren, Olefinen, Vinylisocyaniden und einer Vielzahl vorwiegend funf-, aber auch sechs- und siebengliedriger Aza-, Diaza-, Oxaza- und Thiaza-Heterocyclen.
- Published
- 1974
36. Motion of a spin probe in hexagonal and lamellar potassium palmitate
- Author
-
Jaakko Brotherus and Pertti Törmälä
- Subjects
Polymers and Plastics ,Chemistry ,Potassium ,Radical ,chemistry.chemical_element ,Nitroxyl ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,Spin probe ,Crystallography ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Lamellar phase ,Phase (matter) ,Materials Chemistry ,Lamellar structure ,Physical and Theoretical Chemistry ,0210 nano-technology ,Rotational correlation time - Abstract
Nitroxyl radical Tempol dissolved in the hexagonal liquid-crystalline phase of potassium palmitate experienced a homogeneous time averaged environment. In the lamellar phase the radicals were distributed in two environments of different solvent polarities, which was demonstrated by simulation of the spectra. In both phases the nitroxyl probes were able to tumble comparatively freely (the rotational correlation time a was 0.15–0.9 ns).
- Published
- 1974
37. Isotope Effects of Uranium by Ion Exchange in the System Dowex 50 / α-Hydroxyisobutyrate
- Author
-
Pikka Pietilä, Klaus G. Heumann, and J. Aaltonen
- Subjects
Ion exchange ,Chemistry ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Uranium ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Mass spectrometry ,Uranyl ,Enriched uranium ,01 natural sciences ,0104 chemical sciences ,Ion ,chemistry.chemical_compound ,Column chromatography ,Kinetic isotope effect ,0210 nano-technology - Abstract
In this investigation the isotope effect of uranium in the system Dowex 50 resin/ α- hydroxyisobutyrate solution was studied by mass spectrometry. A recycle ion exchange column was used for the separation experiments. The dependence of the isotope effect on the pH value and on the concentration of the α-hydroxyisobutyrate solution used as eluent was investigated. In the case of a 0.07 ᴍ and a 0.22 ᴍ α-hydroxyisobutyrate solution the elementary separation factor of uranium was calculated to be 1.00019 and 1.00006, respectively. In both cases an enrichment of 235U in relation to 238U was found in the solution. In addition the distribution factor of the uranyl ions in the investigated system was determined in the pH range between 2 and 6. The distribution factor depends strongly on the pH value. With increasing pH values the distribution factor decreases. The results obtained for the elementary separation factor and the distribution factor are compared with other investigations.
- Published
- 1974
38. The Conjugative Interaction between ?-Orbitals and Cyclobutane-Orbitals in Spiro[3.4]octa-5,7-diene and Spiro[3.4]octene-5
- Author
-
Rolf Gleiter, Lüder‐Ulrich Meyer, Armin de Meijere, and Peter Bischof
- Subjects
Diene ,010405 organic chemistry ,Organic Chemistry ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Catalysis ,Spectral line ,0104 chemical sciences ,Cyclobutane ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,chemistry ,Atomic orbital ,Computational chemistry ,Drug Discovery ,Physical and Theoretical Chemistry ,Octene ,Fulvene ,Octane - Abstract
The photoelectron spectra of spiro[3.4]octane (1), spiro[3.4]octene-5 (2), spiro[3.4]-octa-5,7-diene (3), spiro[4.4]nonene-2 (4) and spiro[4.4]nona-2,4-diene (5) have been recorded. The first bands of these spectra are correlated with orbitals which are π-orbitals, Walsh orbitals resp. linear combinations of both. Our assignment is based on a qualitative ZDO-model, it is in satisfactory agreement with the results of extended Huckel calculations. The interaction found in 2 and 3 is of similar magnitude as the one in 4 and 5 and considerably less than that in homofulvene and fulvene.
- Published
- 1974
39. Die Kristallstruktur des polymeren Oktamolybdats, (NH4)6Mo8O27.4H2O
- Author
-
I. Böschen, Bernt Krebs, and Bruno Buss
- Subjects
010405 organic chemistry ,Chemistry ,Polymer chemistry ,General Medicine ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences - Published
- 1974
40. Hydrierung des Furfuralkohols und des Furfurols zu Tetrahydro‐furfuralkohol
- Author
-
Heinrich Wienhaus
- Subjects
010405 organic chemistry ,Chemistry ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences - Published
- 1920
41. Dielektrische Eigenschaften zweier halbleitender, einkristalliner Äthyl-phenothiazin–Jod-Komplexe bei 10 GHz
- Author
-
A. Kehl
- Subjects
Dielectric loss factor ,Materials science ,Dc conductivity ,Analytical chemistry ,Dielectric ,Conductivity ,010402 general chemistry ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,0103 physical sciences ,Dielectric loss ,010306 general physics ,Anisotropy ,Normal behaviour - Abstract
Es wird uber Messungen der Gleichstromleitfahigkeit σ und der komplexen Dielektrizitatszahl ϵ = ϵ′ − j ϵ″ bei 10 GHz an Einkristallen zweier halbleitender, organischer Ladungsubertragungskomplexe berichtet. Beide Komplexe wurden aus N-Athyl-phenothiazin (EPT) und Jod hergestellt. Leitfahigkeit σ und Realteil ϵ′ der Dielektrizitatszahl bei 20°C betragen beim EPT–Jod(I)-Komplex σ = 1,5 (Ωcm)−1, ϵ′ = 500, beim EPT–Jod(II)-Komplex σ = 5 σ 10−4 (Ωcm)−1, ϵ′ = 7 bzw. 12 (anisotrop). Beim EPT–Jod(I)-Komplex sind die dielektrischen Verluste ϵ″ bei Temperaturen unterhalb −50°C wesentlich hoher als erwartet und besitzen einen starken frequenzabhangigen Anteil. Die Verluste des EPT–Jod(II)-Komplexes dagegen zeigen ein normales Verhalten. Measurements of the dc conductivity σ and the complex dielectric number ϵ = ϵ′ − j ϵ″ at 1010 Hz of single crystals of two semiconducting, organic charge-transfer complexes are reported. The complexes were prepared from N-ethyl-phenothiazine (EPT) and iodine. The room temperature values of the conductivity σ and the real part ϵ′ of the dielectric number of the EPT–iodine (I) complex are σ = 1.5 (Ωcm)−1 and ϵ′ = 500, respectively, and of the EPT–iodine(II) complex σ = 5 × 10−4 (Ωcm)−1 and ϵ′ = 7 and 12 (anisotropic), respectively. At temperatures below −50°C the dielectric loss factor ϵ″ of the EPT–iodine(I) complex is substantially higher than expected from dc data and has a strong frequency-dependent part. The dielectric loss of the EPT–iodine(II) complex, however, shows normal behaviour.
- Published
- 1972
42. The photoelectron spectrum of thiazyl fluoride (NSF)
- Author
-
J. Schäuublin, E. Heilbronner, Rolf Gleiter, O. Glemser, and D. O. Cowan
- Subjects
010304 chemical physics ,Photoemission spectroscopy ,Chemistry ,Organic Chemistry ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Catalysis ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Thiazyl fluoride ,0103 physical sciences ,Drug Discovery ,Physical chemistry ,Physical and Theoretical Chemistry - Abstract
The photoelectron spectrum of thiazyl fluoride has been recorded. An assignment of the first five bands has been attempted, using semi-empirical calculations.
- Published
- 1971
43. Zur Kenntnis des IR‐Spektrums optisch aktiver Aminosäuren und ihrer Racemate
- Author
-
Hans Brockmann and Hans Musso
- Subjects
Inorganic Chemistry ,0303 health sciences ,03 medical and health sciences ,Chemistry ,Stereochemistry ,030302 biochemistry & molecular biology ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences - Abstract
Wie am Beispiel des Alanins, Serins und ihrer Anhydride gezeigt, treten bei Antipoden und Racematen, die sich in Schmelzpunkt und Loslichkeit hinreichend unterscheiden, charakteristische Unterschiede im IR-Spektrum auf, die Ruckschlusse auf die Bindung der Molekule im Kristall erlauben. Die Konfiguration der beiden optisch inaktiven, stereoisomeren Alanin- und Serin-anhydride wird auf synthetischem Wege sichergestellt. Beim Pressen in Kaliumbromid konnen Gemische optischer Antipoden in Racemate ubergehen.
- Published
- 1956
44. Umsetzungen von Trifluormethylsulfenylisocyanat mit Halogenwasserstoffen
- Author
-
Alois Haas
- Subjects
Inorganic Chemistry ,010405 organic chemistry ,Chemistry ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,3. Good health ,0104 chemical sciences - Abstract
CF3SNCO bildet mit HCl CF3SNHCOCl, das sich bei 150° uber CF3S[NHCO]6Cl zu CF3SCl und Cyanursaure zersetzt. HBr liefert analog CF3SNHCOBr, das in CF3SSCF3, CF3SH, Brom und (HNCO)3 zerfallt. Mit HJ entsteht CF3SH, Jod und (HNCO)3; CF3SNHCOJ konnte nicht isoliert werden. CF3SSCF3 reagiert mit HBr nicht und mit HJ nur zu 25%, hierbei entstehen CF3SH und Jod.
- Published
- 1965
45. Zur Struktur d�nner, bei tiefer Temperatur kondensierter Salzschichten. I. Alkalihalogenide
- Author
-
Wilhelm Rühl
- Subjects
Physics ,Nuclear and High Energy Physics ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,01 natural sciences ,Molecular biology ,0104 chemical sciences - Abstract
Im vorliegenden ersten Abschnitt uber rontgenographische Untersuchungen an dunnen abgeschreckt kondensierten Salzschichten wird uber die Mesergebnisse an Alkalihalogeniden berichtet. DieDebye-Diagramme sind unmittelbar nach der Entstehung der Schichten bei 20° K und in verschiedenen Stadien der Temperung aufgenommen. Gleich nach der Kondensation findet man verbreiterte Interferenzen. Die Halbwertsbreiten der ersten Linien sind fur jeden Stoff einzeln angegeben. Sie betragen 0,4 bis 0,7Braggsche Winkelgrade. Aus der Linienverbreiterung last sich auf eine Mindestkorngrose innerhalb der frisch kondensierten Schichten von 100 bis 200 A schliesen. Doch spielen auserdem auch Verspannungen verschiedener Herkunft eine merkliche Rolle.
- Published
- 1956
46. Synthesen mit α‐metallierten Isocyaniden, XXV. 4‐Cyan‐2‐isocyanalkansäure‐äthylester, 4‐Cyan‐2‐(formylamino)alkansäure‐äthylester und 4‐Cyan‐5(4)‐pyrrolin‐2‐carbonsäure‐äthylester aus α‐metallierten Isocyanalkansäure‐äthylestern und Acrylnitrilen
- Author
-
Ulrich Schöllkopf and Paul‐Hermann Porsch
- Subjects
Ethanol ,Sodium ethoxide ,010405 organic chemistry ,Stereochemistry ,Hydrochloric acid ,Ethyl ester ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Adduct ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry - Abstract
4-Cyan-2-isocyanalkansaure-athylester (7, 8, 9) entstehen aus Acrylnitrilen 5 und Isocyanessigsaure-athylester bzw. -propionsaure-athylester (1 bzw. 2) in Athanol in Gegenwart katalytischer Mengen Natriumathylat bei ca. 30°C. Mit Salzsaure in Athanol erhalt man daraus 4-Cyan-2-(formylamino)alkansaure-athylester (z. B. 10). Die mit 2 erhaltlichen Addukte 8 cyclisieren bei ca. 65°C in Athanol mit aquivalenten Mengen Natriumathylat zu 4-Cyan-5-bzw. -4-pyrrolin-2-carbonsaure-athylestern (12 bzw. 13). Syntheses with α-Metalated Isocyanides, XXV Ethyl 4-cyano-2-isocyanoalkanoates (7, 8, 9) are obtained by the reaction of acrylonitriles 5 with ethyl isocyanoacetate (1) or ethyl isocyanopropionate (2) in ethanol with catalytic amounts of sodium ethoxide at ca. 30°C. These can be transformed to ethyl 4-cyano-2-(formylamino)alkanoates (for instance 10) by treatment with hydrochloric acid in ethanol. The adducts 8 from 2 and 5 undergo cyclization to 4-cyano-5- and -4-pyrroline-2-carboxylic ethyl esters, respectively (12 and 13).
- Published
- 1973
47. Zur kenntnis der rubromycine
- Author
-
Gerd Schwantje, Axel Zeeck, Werner Lenk, and Hans Brockmann
- Subjects
010405 organic chemistry ,Chemistry ,Organic Chemistry ,Drug Discovery ,Library science ,010402 general chemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences - Published
- 1966
48. N ‐Halogen‐schwefeldifluoridimide, V. Über die Addition von N ‐Halogen‐schwefeldifluoridimiden an asymmetrische Chlor‐fluor‐ und Fluoralkene
- Author
-
Rüdiger Mews and Oskar Glemser
- Subjects
Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,13. Climate action ,010405 organic chemistry ,Yield (chemistry) ,Difluoride ,010402 general chemistry ,Imide ,01 natural sciences ,Medicinal chemistry ,3. Good health ,0104 chemical sciences - Abstract
Bei den Bestrahlungsreaktionen des N-Chlor-schwefeldifluoridimids, CINSF2 (1), mit CF2CFCl, CF2CCl2, CFClCCl2, CF2CHF, CF2CH2 und CHFCH2 entstehen die N-Alkyl-schwefeldifluoridimide CFCl2CF2NSF2 (6), CCl3CF2CCl2CF2NSF2 (3), F2SNCF2CCl2CCl2CF2 NSF2 (4), CCl3CFClNSF2 (10), CF2ClCHFNSF2 (12), CHFClCF2NSF2 (18), CF2ClCH2NSF2 (15), CH2ClCF2NSF2 (20) und CHFClCH2NSF2 (17); BrNSF2 (5) und CCl2CFCl ergeben unter den gleichen Bedingungen CCl2BrCFClNSF2 (11). Die thermischen Reaktionen von BrNSF2 mit CFClCF2 liefern CFClBrCF2NSF2 (7), mit CF2CHF und CF2CH2 die Isomerengemische aus CF2BrCHFNSF2 (13) und CHFBrCF2NSF2 (19) bzw. CF2BrCH2NSF2 (16) und CH2BrCF2NSF2 (21). Ein Mechanismus fur die radikalische Addition wird vorgeschlagen sowie ein kurzer Uberblick uber die IR- und NMR-Spektren der N-Alkyl-schwefeldifluoridimide gegeben (unter Einbeziehung der Daten fur die auf anderem Wege dargestellten Verbindungen CCl3CF2NSF2 (9), CHCl2CF2NSF2 (8), CCl2BrCHFNSF2 (22) und CHClBrCHFNSF2 (14)). N-Halosulfur Difluoride Imides, V. On the Addition of N-Halosulfur Difluoride Imides to Asymmetric Chloro-fluoro- and Fluoroalkenes Irradiation of N-chlorosulfur difluoride imide, CINSF2 (1) in the presence of CF2CFCl, CF2CCl2, CFClCCl2, CF2CHF, CF2CH2 and CHFCH2 produces the N-alkyl-sulfur difluoride imides CFCl2CF2NSF2 (6), CCl3CF2CCl2CF2NSF2 (3), F2SNCF2CCl2CCl2CF2 –NSF2 (4), CCl3CFClNSF2 (10), CF2ClCHFNSF2 (12), CHFClCF2NSF2 (18), CF2ClCH2NSF2 (15), CH2ClCF2NSF2 (20) and CHFClCH2NSF2 (17) Under the same conditions BrNSF2 (5) reacts with CCl2CFCl to give CCl2BrCFClNSF2 (11). BrNSF2 reacts thermally with CFClCF2 to yield CFClBrCF2NSF2 (7) and with CF2CHF or CF2CH2 to produce the isomeric mixtures CF2BrCHFNSF2 (13) and CHFBrCF2NSF2 (19) or CF2BrCH2NSF2 (16) and CH2BrCF2NSF2 (21), respectively. A mechanism for the radical addition is proposed. The data for the i. r. and n. m. r. spectra of N-alkylsulfur difluoride imides is briefly summarized (including the data for CCl3CF2NSF2 (9), CHCl2CF2NSF2 (8), CCl2BrCHFNSF2 (22), and CHClBrCHFNSF2 (14), which were prepared by another method).
- Published
- 1971
49. Beiträge zur systematischen Verwandtschaftslehre. 92. Iridiumphosphide
- Author
-
Karl Heinz Söffge, Wilhelm Biltz, and Max Heimbrecht
- Subjects
010405 organic chemistry ,Chemistry ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences - Published
- 1940
50. Spektrum und Leuchtproze� von kristallinem Terbiumbromat
- Author
-
K. H. Hellwege and H. F. Geisler
- Subjects
Physics ,Nuclear and High Energy Physics ,13. Climate action ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,01 natural sciences ,Medicinal chemistry ,Ultraviolet radiation ,0104 chemical sciences - Abstract
Die Fluoreszenz- und Absorptionsspektren von pseudohexagonalen Einkristallen von Tb(BrO3)3 ·9H2O sind photographiert worden. An Hand der Polarisation der Linien werden magnetische und vom Kristallfeld erzwungene elektrische Dipolstrahlung festgestellt. Mit Hilfe der Auswahlregeln fur die magnetische Dipolstrahlung ergibt sich5D4 als Ausgangsterm der Fluoreszenz. — Die Wahrscheinlichkeiten fur strahlende und strahlungslose Ubergange werden aus den Intensitaten von Emissions- und Absorptionsbanden und der Abklingkonstanten der Fluoreszenz bestimmt. Sie sind von derselben Grosenordnung wie bei den Europiumsalzen. Strahlungsprozesse sind zwei Grosenordnungen unwahrscheinlicher als strahlungslose Abgabe der absorbierten Energie an Warmeschwingungen. Deshalb hangt die Lebensdauer des angeregten5D4-Terms praktisch nur von den strahlungslosen Prozessen ab. — Durch die erregende UV-Strahlung wird das BrO3-Ion zersetzt. Die so erzeugten Fehlstellen im Gitter andern das elektrische Kristallfeld am Ort des Tb+++-Ions nicht merklich, verlangern aber die Lebensdauer des angeregten Terms durch Behinderung der strahlungslosen Energie-Umwandlungsprozesse.
- Published
- 1953
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