Diethyl carbonate, pyrolysis

CARBENE. The name quite generally used for the methylene radical, CH,. It is formed during a number of reactions. Thus the flash photochemical decomposition of ketene (CH2=C=0) has been shown to proceed in two stages. The first yields carbon monoxide and CHj. the latter then reacting with more ketene to form ethylene and carbon monoxide. Carbcne reacts by insertion into a C- H bond to form a C-CH, bond. Thus carbene generated from ketene reacts with propane to form, i-butane and isobutane. Carbene generated by pyrolysis uf diazomethane reacts with diethyl ether to form ethylpropyl ether and ethylisopropyl ether. 

Diacetyltartaric anhydride, acetoxy maleic anhydride and diethyl oxaloacetate all yield carbon suboxide, C3O2 on pyrolysis. Carbon suboxide and protonated carbon suboxide are prominent ions in the mass spectra of all three of these compounds. 

Primary process (11) is also believed to proceed through a vibrationally excited ground-state molecule since it is also subject to pressure quenching, even at low pressures. This would fall in line with studies on the pyrolysis of l,S cyclohexadiene, which show that hydrogen, acetylene, ethylene, and benzene are products of the thermal reaction. Besides self-quenching, the use of inert gases such as xenon, carbon dioxide, propylene, and diethyl ether as quenchers has been investigated. ... 

Martin-Gil et al. reported on the synthesis of cubic carbon nitride with the zinc blende structure by pyrolysis of N,N-diethyl-l,4-phenylene-diammonium sulphate at 800°C in an N2 atmosphere using Se02 as a catalyst [90]. The material obtained contained both an amorphous matrix and polycrystalline regions with crystallites of 5-50 nm in size. The sample as whole had a composition with 0.2 estimated using EELS (electron energy loss spectroscopy) data to be C N, with x and y between 3 and 4. The... 

As shown in Scheme 12.54, when ort/io-nitrotoluene is allowed to react with diethyl oxylate in the presence of sodium (or potassium) ethoxide, a condensation occurs and ethoxide is eUminated. Then, with zinc (Zn) in acetic acid, reduction of the nitro group and cyclization to the keto carbonyl occurs. Hydrolysis results in the formation of the indole-2-carboxyUc acid and pyrolysis leads to decarboxylation with the formation of the free base and carbon dioxide (CO2). 

Products obtained by pyrolysis of other polymers is reviewed in Table 4.5. Some specific applications of the chromatography-MS technique to various types of polymers include the following PE [34,35], poly(l-octene) [29], poly(l-decene) [29], poly(l-dodecene) [29], CPE [36], polyolefins [37, 38], acrylic acid-methacrylic acid copolymers [39, 40], polyacrylate [41], nitrile rubber [42], natural rubbers [43, 44], chlorinated natural rubber [45, 46], polychloroprene [47], PVC [48-50], polysilicones [51, 52, 53], polycarbonates [54], styrene-isoprene copolymers [55], substituted olystyrene [56], PP carbonate [57], ethylene-vinyl acetate [58], Nylon 66 [59], polyisopropenyl cyclohexane-a-methyl styrene copolymers [60], cresol-novolac epoxy resins [61], polymeric flame retardants [62], poly(4-N-alkyl styrenes) [63], polyvinyl pyrrolidone [64], polybutyl-cyanoacrylate [65], polysulfides [66], poly(diethyl-2-methacryl-oxy) ethyl phosphate [67, 68], polyetherimide [69], bisphenol-A [70], polybutadiene [71], polyacenaphthalene [72], poly(l-lactide) [73], polyesterimide [74], polyphenylene triazine [75], poly-4-N-vinyl pyridine [76], diglycidylether-bisphenol-A epoxy resins [77], polyvinylidene chloride [78] and poly-p-chloromethyl styrene [79]. 

---