- Pyrolysis nozzles coupled to a microwave spectrometer with stark modulation for the detection of transients species in a supersonic expansion
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Two types of pyrolysis nozzles have been constructed and coupled to a new Stark modulated microwave spectrometer. The nozzles were tested on their ability to generate rotationally cooled transient species through a supersonic expansion. The transients species vinylamine, thioketene and ketene were generated and detected using nozzle temperatures ranging from 400-800°C. Pyrolysis temperatures were generally lower than those used in normal flow pyrolysis experiments and rotational temperatures of ca. 10 K were achieved. A preliminary investigation of the jet nozzle pyrolysis of 3-methyl-4-hydroxyiminoisoxaline-5-one was carried out and showed a different distribution of CHNO pyrolysis products to that observed in previous low pressure studies. by Oldenbourg Wissenschaftsverlag, Muenchen.
- McNaughton, Don,Evans, Corey J.
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p. 1313 - 1327
(2007/10/03)
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- Reactive Nitrogenous Molecules from Meldrum's Acid Derivatives, Pyrrole-2,3-diones, and Isoxazolones
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Flash vacuum pyrolysis of 5-(aminomethylidene)-2,2-dimethyl-1,3-dioxane-4,6-diones (Meldrum's acid derivatives) 12 gives 4-hydroxyquinolines/4-quinolones 15 or 3-enaminoacroleins 22 in good to excellent yields.Intermediate (aminomethylene)ketenes and imidoylketenes are directly observed and their transformation into product 22 monitored by low-temperature IR spectroscopy.Imidoylketenes are also formed and observed upon thermal CO extrusion from pyrrole-2,3-diones 16.Isocyanoamines and fulminates are generated by pyrolysis of hydrazono- or oximino-Meldrum's acid derivatives 32 and 39, monitored by IR spectroscopy, and found to rearrange to cyanamides and cyanates, depending on substituents.The thermal reactions of isoxazol-5(4H)-ones and Meldrum's acid derivatives are compared and discussed.
- Briehl, Horst,Lukosch, Adelheid,Wentrup, Curt
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p. 2772 - 2779
(2007/10/02)
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