47 & PRINCIPLES OF CHEMISTEY 



The resulting product of metalepsis, or chloride of nitrogen, NC1 3 , 

 discovered by Dulong, is a liquid having the property of decomposing 

 with excessive ease not only -when heated, but even under the action 

 of mechanical influences, as by a blow or by contact with certain solid 

 substances. The explosion which accompanies the decomposition is due 

 to the fact that the liquid chloride of nitrogen gives gaseous products, 

 nitrogen and chlorine. 29 bis 



(probably by virtue of the affinity of hydrochloric acid for ammonia). Therefore there 

 must exist a very interesting case of equilibrium between ammonia, hydrochloric acid, 

 chlorine, water, and chloride of nitrogen which has not yet been investigated. The re- 

 action NCl5-f-4HCl = NH 4 Cl + 8Cl. i enabled Deville and Hautefeuille to determine the 

 composition of chloride of nitrogen, When slowly decomposed by water, chloride of 

 nitrogen gives, like tf chloranhydride, nitrous acid or its anhydride, 2NC1 3 + 3H 2 O 

 = N a O 5 + 6HC1. From these observations it ie evident that chloride of nitrogen presents, 

 great chemical interest, which is strengthened by its analogy with trichloride of phos- 

 phorus. The researches of F. F. Selivanoff (1891-94) prove that NC1 3 may be regarded 

 as an ammonium derivative of hypochlorous acid. Chloride of nitrogen is decomposed by 

 dilute sulphuric acid in the following manner : NC1 3 + 8H 2 + H 2 S0 4 = NH 4 HSO 4 + 3HC1O. 

 This reaction is reversible and is only complete when some substance, combining with 

 HC1O (for instance, succinimide) or decomposing it, is added to the liquid. This ia 

 easily understood from the fact that hypochloroua acid itself, HC10, may, according to 

 the view held in this book, be regarded as the product of the metalepsis of water, and 

 consequently bears the same relation to NC1 3 as H 2 O does to NH 3 , or as RHO to 

 RNH 2 , R 2 NH, and R 3 N that is to say, NC1 3 corresponds as an ammonium derivative to 

 C10H and C1 2 in exactly the same manner as NR 3 corresponds to ROH and R 2 . The 

 connection of NC1 3 and other similar explosive chloro-nitrogen compounds (called 

 chloryl compounds by Selivanoff ; for example, the C 2 H 5 NC1 2 of Wurtz is chloryl ethyl- 

 amine), such as NRC1 2 (as NC 2 H 5 C1 2 ), and NR 2 C1 (for instance, N(CH 3 CO)HC1, chloryl- 

 acetamide, and N(C 2 H 5 ) 2 C1, chloryl diethylamine) with HC1O is evident from the fact 

 that under certain circumstances these compounds give hypochlorous acid, with water, for 

 instance, NR 2 C1 + H 2 O = NR 2 H + HC1O, and frequently act (like NC1 3 and HC1O, or C1 2 ) 

 in an oxidising and chloridising manner. We may take chloryl succinimide, C 2 H 4 (CO) 2 NC1 

 for example. It was obtained by Bender by the action of HC1O upon succinimide, 

 C 2 H4(CO) 2 NH, and is decomposed by water with the re-formation of amide and HC1O 

 (the reaction is reversible). Selivanoff obtained, investigated, and classified many of 

 the compounds NR 2 C1 and NRC1 2 , where R is a residue of organic acids or alcohols, and 

 showed their distinction from the chloranhydrides, and thus supplemented the history of 

 chloride of nitrogen, which is the simplest of the amides containing chlorine, NR 3 , where 

 R is fully substituted by chlorine. 



29 bis i n preparing NC1 3 every precaution must be used to guard against an explosion, 

 and care should be taken that the NG1 3 remains under a layer of water. Whenever an 

 ammoniacal substance comes into contact with chlorine great care must be taken, 

 because it may be a case of the formation of such products and a very dangerous explosion 

 may ensue. The liquid product of the metalepsis of ammonia may be most safely pre- 

 pared in the form of small drops by the. action of a galvanic current on a slightly warm 

 solution of sal-ammoniac ; chlorine is then evolved at the positive pole, and this chlorine 

 acting on the ammonia gradually forms the product of metalepsis which floats on the 

 surface of the liquid (being carried up by the gas), and if a layer of turpentine be 

 poured on to it these small drops, on coming into contact with the turpentine, give feeble 

 explosions, which are in no way dangerous owing to the small mass of the substance 

 formed. Drops of chloride of nitrogen may with great caution be collected fo 

 investigation in the following manner. The neck of a funnel is immersed in a basin con- 

 taining mercury, and first a saturated solution qf common salt is poured into the funnel, 



