Heating contact

If one of the conditions in the fire triangle is missing, fire does not occur, and if one is removed, fire is extinguished. Usually a fire occurs when a source of heat contacts a combustible material in air, and then the heat is supphed by the combustion process itself. 

Although the hazardous properties of di-tert-butyl diazomalo-nate are not known with certainty, it is reasonable to assume that they are similar to those of diazoacetic esters, which are considered to be moderate explosion hazards when heated. Contact with rough or metallic surfaces should be avoided. The submitter has routinely distilled 10-g. quantities of di-ferf-butyl diazomalonate under argon with no sign of decomposition. 

A special type of micro DTA-holder (Fig. 13 c) uses large-surface, vapor-deposited thermopiles as the AT sensor which assure excellent heat contact with the crucibles. No undesirable heat exchange occurs at the sensor leads which are also vapor-deposited. This results in high sensitivity and precision. 

A number of research groups have explored vapour phase pyrolytic reactions using apparatus designs (available from, for example, Aldrich), which allow for controlled vapour flow (and hence heat contact time), under moderate to high vacuum conditions. These techniques enable preparative procedures to be developed which involve the trapping of reaction intermediates (e.g. carbenes, nitrenes, arynes, etc.), and also the study of very short-lived species by the interfacing of the pyrolysis unit with, for example, a mass spectrometer. This specialist area has been comprehensively reviewed.26... 

Heat, contact with combustible material, acid ... 

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