Pyrophoric compounds

Methyl bromide, when dry (<100 ppm water), is inert toward most materials of constmction. Carbon steel is recommended for storage vessels, piping, pumps, valves, and fittings. Copper, brass, nickel, and its alloys are sometimes used. Aluminum, magnesium, zinc, and alloys of these metals should not be used because under some conditions dangerous pyrophoric compounds may be formed. Many nonmetallic materials are also useful for handling methyl bromide, but nylon and polyvinyl chloride should be avoided. 

Not only the preparation of so far unknown compounds, but also the development of new synthesis techniques such as the Schlenk technique and vacuum-line technique which allow the handling and manipulation of air- and moisture-sensitive, pyrophoric compounds, are the most striking breakthroughs of their fascinating work. 

The pyrophoric compound previously regarded as dodecacarbonyl divanadium [1] is now known to be the monomeric hexacarbonylvanadium [2],... 

English transl. by D. S. Rosenberg, 10.2.69 of German transl. by S. Vedrilla (Chemiebau) of Low Temperature Pyrophoric Compounds in Process for Preparing Phtbalic Anhydride , a Japanese paper in Anzen Kogyo Kogaku, 1968... 

By far the most important redox reaction relative to chemical stability is the reaction between an oxidizable material and oxygen from air. The particle size and any droplets have a large effect on the combustion properties. Some substances react so rapidly in air that ignition occurs spontaneously. These so called pyrophoric compounds (white phosphorus, alkali metals, metal hydrides, some metal catalysts, and fully alkylated metals and nonmetals) must be stored in the absence of air. 

This class of flammable, air-sensitive and usually pyrophoric compounds includes the groups ... 

Measurements of the autoignition temperatures for several series of mono-, di-, tri-and tetra-alkylsilanes showed that the ease of oxidation decreases with increasing substitution. In this group of easily ignited or pyrophoric compounds, individually indexed compounds are ... 

Dilithiated diamine 2 was synthesized by Karsch by a two-fold metalation of N,N,N, N tetramethylmethylenediamine (TMMDA) (1). The reaction was effected in n-pentane at low temperatures, yielding the poorly soluble Af,Af -bis(fithiomethyl)-Af,Af -dimethyl-methylenediamine (2) (Scheme 1). Due to its low solubility in toluene or THE, the highly pyrophoric compound was characterized by derivatization with several electrophiles, mainly chlorosilanes. Obviously, the addition of coordinating additives, such as TMEDA, DME (dimethoxyethane) or THE, does not enhance the solubility of the dilithium compound. Interestingly, as the author comments, TMEDA is only monolithiated in modest yields by alkyllithium bases. 

Caution. The residues on the glassware and the frit may contain sodium-potassium alloy and/or tris(trimethylsilyl)arsine and should not be exposed to air until disposal. tert-Butyl alcohol and isopropyl alcohol can be used to destroy these pyrophoric compounds however, this should be performed in a fume hood, as arsine gas may be generated. The solid on the frit can be mixed with class D metal fire extinguisher and subsequently treated with either of the aforementioned alcohols. 

Pyrophoric Compounds Compounds that Are Reactive with Air... 

PYROPHORIC COMPOUNDS COMPOUNDS THAT ARE REACTIVE WITH AIR... 

Diethylmagnesium, Mg(C2H5)2, is described as a pyrophoric compound that is violently reactive to water and steam and that self-ignites in air, burning even in a carbon dioxide atmosphere. Describe the significance of this description in terms of reactivity, susceptibility to hydrolysis or oxidation, and potential toxic effects. 

The green, pyrophoric compound U(C8H8)2, known as uranocene, was first made in 1968 by the reaction... 

Caution should be used when working with trisacetonitriletricarbonylchromium, as it is a pyrophoric compound. 

H. Pyrophoric Compounds are materials that ignite spontaneously in air at a temperature below 130°F. They require special storage in containers that are sealed in inert gas. 

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