Hydride inflammation

An alternative method for ascertaining the end of the reaction, which does not involve the removal of the cover, is to conduct the exit gas through an empty wash bottle (to eict as a trap in case of sucking back ) and then collect a sample in a test-tube over water. If an inflammable gas (hydrogen) is absent, the reaction may be considered complete. Under no circumstances should the reaction be stopped until all the sodium has completely reacted too early arrest of the reaction may result in the product containing sodium hydride, which appears to be partially responsible for the explosive properties of the impure substance ... 

The temperature must be raised slowly to avoid formation of spontaneously inflammable hydrides of phosphorus whict will ignite and destroy the preparation. A similar result occur if the phosphorus tribromide is added at 170°. 

The metal itself, having an appreciable vapour pressure, is also toxic, and produces headaches, tremors, inflammation of the bladder and loss of memory. The best documented case is that of Alfred Stock (p. 151) whose constant use of mercury in the vacuum lines employed in his studies of boron and silicon hydrides, caused him to suffer for many years. The cause was eventually recognized and it is largely due to Stock s publication in 1926 of details of his experiences that the need for care and adequate ventilation is now fully appreciated. 

Exposure of animals to concentrations above 5 mg/nf caused sneezing and cough with secondary pulmonary emphysema levels of 10 mg/nf corroded the body fur and skin of the legs, and there was occasional inflammation of the eyes and nasal seprnrn. The lesions of the nose and legs were attributed to the alkalinity of lithium hydroxide, the hydrolysis product of lithium hydride. 

The spontaneously inflammable nature of the higher phosphines decreases with increasing phosphorus content. At room temperature or on exposure to light, phosphorus-rich, yellow, solid phosphines are rapidly formed these can also be obtained directly by thermal decomposition of diphosphine. The literature on these types of higher phosphorus hydrides which are, in general, solid and are thus refered to as solid phosphorus hydrides is abundant and... 

Aminoboronhydride Compounds. Many amino-boronhydride compds and their derivatives are volatile and self-inflammable. A series of papers by H.I.Schlesinger et al published in JACS on boron hydrides(qv) include the prepn and props of the following amino-boronhydrides and their derivatives borine-amine, H,N BH, or BHSN dimethylamino-borine(or dimethylaminoboric add) (CH,)2 BNHa dimethylamioodiborane(CH,)2NB2Hs bor-inetriamine B,N,Hg borinetrimethylene (CHJ,NBH aminodiborane HaN BaH, or BjHjN methylaminodiborane CH,HN "... 

The chemical properties partly resemble those of white, partly those of red, phosphorus. It does not glow in the air, but does so in ozone. It is rapidly attacked by alkalies, giving hypophosphite and phosphine which is not spontaneously inflammable. It is coloured intensely black by ammonia. It dissolves in aqueous alcoholic potash giving red solutions from which acids precipitate a mixture of phosphorus and solid hydride. It dissolves in phosphorus tribromide to the extent of about 0-5 gram in 100 grams of the solvent at about 200° C. It is said to be non-poisonous its physiological properties probably resemble those of red phosphorus (q.v.). 

The phosphine so obtained usually inflames spontaneously on coming into contact with the air each bubble as it escapes forms a beautiful vortex ring of smoke. It was early shown that the spontaneous inflammability is due to the presence of small quantities of a hydride, liquid at ordinary temperatures,3,4 which has the empirical composition (PHa),8 and the molecular composition P2H4. The phosphorus must therefore react also according to the equation... 

Boron forms several hydrides, the simplest of which is diborane, BgHg, a poisonous, ill-smelling, spontaneously inflammable gas. 

Aluminum alkyls, although inconvenient to handle because of their spontaneous inflammability, are powerful reducing agents and are applied to the synthesis of transition-metal hydrides . They, and the organomagnesium halide reagents to be discussed in 1.10.8.4, function by initial alkylation of the transition metal (e.g., for EtjAl) ... 

The silanes are very easily oxidized, Si2Hg, for exampie, being spontaneously inflammable in air. In marked contrast to carbon, silicon appears to form no simple unsaturated hydrides corresponding to the olefines, acetylenes, and aromatic hydrocarbons. Solid unsaturated hydrides such as (SiH2) , of unknown constitution, have been described, though in a study of the higher silanes no solid products were found at any stage. Structurally the silanes are presumably similar to the saturated hydrocarbons. Many substituted monosilanes have been prepared, for example ... 

Silicon has a much greater affinity than carbon for oxygen. For example, SiCl4 is violently hydrolysed by water, whereas CCI4 is stable towards water and is only slowly hydrolysed by aqueous alkali. The silicon hydrides are hydrolysed to silicic acid, and disilane is spontaneously inflammable in air—contrast the stability of the corresponding hydrocarbons. 

Antimony hydride is a colourless, inflammable gas with a characteristic damp and weak hydrogen sulphide smell. It burns with a greenish flame, producing a white smoke of steam and antimony trioxide. 1 cni. weighs 5 302 mgnus. at 0° and 754 mm. pressure. On an average it is 4360 times heavier than air and 3994 times heavier than oxygen. The observed density, on account of molecular association or of molecular attraction, is 2 95 per cent, more than the theoretical one. 

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