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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 32 (1987), S. 1957-1967 
    ISSN: 1572-8943
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung In der ersten Stufe der thermischen Zersetzung von diarylsubstituierten 2H-Tetrazolen aus der Schmelze werden unter Stickstoffeliminierung Diphenylnitrilimine gebildet. Sie reagieren trotz der drastischen Reaktionsbedingungen relativ selektiv und ergeben bevorzugt zwei Hauptprodukte — die entsprechend substituierten 1,2,4,5-Tetrazine und die 1,2,4-Triazole (zusammen mehr als 70%). Die Triazole werden gebildet, wenn günstige Bedingungen für eine Nitrenabspaltung aus den Nitriliminen vorliegen, was zu größeren Masseverlusten führt, als allein für N2 zu erwarten wäre. Die nach der ersten TG-Stufe vorliegenden Produkte werden mit den Titelmethoden untersucht, insbesondere durch rechnergestützte MS-Analyse.
    Abstract: Резюме На первой стадии терм ического разложения диарилзамещенных 2Н-т етразолов происходит отщеплен ие азота с образовани ем дифенилнитрилимино в. Несмотря на жесткие условия реакции, они о тносительно селекти вно реагируют с образова нием двух основных продуктов: 1,2,4,5-тетразин ов и 1,2,4-триазолов (их сов местный выход составляет бол ее 70%). Триазолы образуются в том случае, если предпочтительным яв ляется выделение нит ренов из нитрилиминов. В связи с этим, наблюдаемые по тери веса на первой стадии разл ожения намного выше ожидаемых при вы делении только азота. Полученную на первой ТГ стадии ра зложения смесь продуктов иссл едовали, главным обра зом, масс-спектрометриче ским методом.
    Notes: Abstract Elimination of nitrogen from diaryl substituted 2H-tetrazoles during the first step of thermal decomposition yields diphenylnitrileimines. In spite of the. drastic reaction conditions of the melt, they react relatively selective, giving two main products, the 1,2,4,5-tetrazines and 1,2,4-triazoles (together more than 70%). The triazoles are formed if the separation of nitrenes from the nitrileimine is favoured. Therefore, the mass losses found for the first step exceed the values calculated for N2 only. The product mixture after the first TG step was investigated by the title methods, and especially by means of computer-aided MS analysis.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 33 (1988), S. 1201-1206 
    ISSN: 1572-8943
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Das bei der thermischen Zersetzung von 2,5-Diaryl-2H-tetrazolen im ersten Schritt gebildete Produktengemisch wurde nach Abschrecken auf Zimmertemperatur und Auflösen in Dichlormethan massenspektrometrisch untersucht. Dazu wurde das multivariate Auswertungsprogramm SEKOS benutzt, das auf einer Computer-gestützten Analyse von Intensität-Zeit-Kurven mehrkomponentiger Mischungen im Massenspektrometer beruht. Das Arbeitsprinzip und die Vorteile des Auswerteprogramms werden erklärt.
    Abstract: РЕжУМЕ МАсс-спЕктРОМЕтРИЧЕ скИ ИсслЕДОВАНА сМЕс ь пРОДУктОВ, ОБРАжУУЩИ хсь НА пЕРВОИ стАДИИ тЕРМИЧЕскОгО РАжлОж ЕНИь НЕкОтОРых 2,5-ДИАРИл-2Н-тЕтРАжОлОВ, пОслЕ Их ОхлАжДЕНИь Д О кОМНАтНОИ тЕМпЕРАтУ Ры И пОслЕДУУЩЕгО РАс тВОРЕНИь В МЕтИлЕНхлОРИДЕ. БылА ИспОльжОВАНА SEKOS пРОгРАММА ОцЕНкИ сО МНОгИМИ пЕРЕМЕННыМИ, ьВльУЩАьсь ОсНОВОИ к ОМпьУтЕРНОгО АНАлИж А кРИВых ИНтЕНсИВНОст ь — ВРЕМь МНОгОкОМпОН ЕНтНых сМЕсЕИ В МАсс-спЕктРО МЕтРЕ. ОБЩьсНЕНы пРИНцИпы РАБОты И пРЕ ИМУЩЕстВА тАкОИ пРОг РАММы.
    Notes: Abstract The product mixtures formed during the first step of thermal decomposition of some 2,5-diaryl-2H-tetrazoles were investigated by MS analysis after quenching of the mixtures to room temperature and dissolution in methylene chloride. The multivariate evaluation program SEKOS was used. This is based on the computer-aided analysis of intensityvs. time curves of multicomponent mixtures in a mass-spectrometer. The working principles and the advantages of the evaluation program are discussed.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 327 (1985), S. 96-102 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemistry of Diarylsubstituted 2H-Tetrazoles. II. The Influence of the Substituents on the Absorption Properties of Diarylsubstituted NitriliminesIrradation of 2,5-diaryl-2H-tetrazoles in an EPA-glass (ether: i-pentan: ethanol=5:5:2) or in an i-pentan glass at 77-80 K with UV-light of wavelength 290 nm yields diarylnitrilimines by the extrusion of nitrogen. The photoreactions investigated show spectroscopic unity. 22 diarylnitrilimines are included in the discussion with regards to the influence of substituents on the absorption maxima. The influence of substituents is interpreted by a LFE-relationship. An intramolecular charge transfer as the reason for the relatively strong dependence of νa∼max-values on substituents is discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 332 (1990), S. 113-116 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermal Behaviour of 2-Diazo-1,2-dihydro-naphthalen-1-ones (Naphthoquinonediazide-NQD)No Abstract.
    Additional Material: 1 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 330 (1988), S. 887-892 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemistry of Bis-2H-tetrazoles. V. Flash Spectroscopic Indication of Bisnitrile IminesThe flash photolysis of bis-2H-tetrazoles 3--hyphen;6 was investigated. Nitrile imines were detected spectroscopically as short living intermediates. The absorption maxima of the bis(nitrile imines) 9--hyphen;12 are between 360 and 450 nm. The values are in agreement with those obtained by low temperature photolysis of bis-2H-tetrazoles. For some bis(nitrile imines) a strong influence of the temperature on the absorption maxima was found. The reaction kinetics of bis(nitrile imines) in ethanol and cyclohexane in the presence of acetic acid and acrylonitrile are described.
    Additional Material: 3 Ill.
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  • 6
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemistry of Bis-2H-tetrazoles. III. Detection of Bisnitrilimines through Low-Temperature-UV-Spectroscopy and Thermic Consecutive Reactions through Photolysis of Bis-2H-tetrazolesThe photolysis of 2H-tetrazoles (1) leads to nitrilimines. Bis-2H-tetrazoles form correspondingly bisnitrilimines 2. They were detected directly by the photolysis of bis-2H-tetrazoles (1) in an ethanol/ether glass at 95 K. The absorption maxima are depend in an expected manner on the substituents. In the presence of dipolarophiles the reaction of bis-2H-tetrazoles (1) at room temperature gives bis-Δ2-pyrazolines (3). These reactions can also be explained by a photoreaction of bis-2H-tetrazoles (1) to bisnitrilimines 2 at 95 K and subsequent cycloaddition above 150 K. Some bis-Δ2-pyrazolines (3) are described.The photolyses of bis-2H-tetrazoles (1) to the bisnitrilimines 2 proceed as one step eliminations of two molecules of nitrogen.
    Additional Material: 3 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 330 (1988), S. 629-633 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemistry of Arylsubstituted 2H-Tetrazoles X. Sulfonated 2,5-Diaryl-2H-tetrazoles
    Additional Material: 1 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 330 (1988), S. 1006-1014 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of Some New 3,4-DiarylsydnonesThe synthesis of some new sydnones 4 is described. Their characteristic absorption maxima, mass spectroscopic fragmentation and C=O-valence vibrations are given. The sydnones 4 are synthezid by nitrosation of C, N-diarylglycines 3 (from strecker synthesis) and subsequent cyclization with Ac2O. The primarily formed C,N-diaryl-α-aminoacetic acid nitrils (1) are decomposed with conc. HCl yielding glycines (3) in good yields.
    Additional Material: 4 Tab.
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  • 9
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemistry of Diarylsubstituted 2H-Tetrazoles. VI. Quantumyields of the Photolysis of Diarylsubstituted 2H-TetrazolesThe photoexcitation of diarylsubstituted 2H-tetrazoles in ethanol in the presence of methylmethacrylat (MMA) yields quantitatively 1,3-diaryl-Δ2-pyrazolines. The photoreactions investigated are spectroscopically uniform. The influence of the substituents on the quantum yields of the photolysis of 2H-tetrazoles (1a - 1x) is discussed.
    Additional Material: 3 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 1111-1115 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bis-2H-tetrazoles. I. Synthesis of Bis-tetrazoles with 2-Phenyl-2H-tetrazol-5-carboxylic Acid Chloride
    Additional Material: 1 Tab.
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