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SCIENCE 



[N. S. Vol. XXX. No. 775 



halide give different ratios of N-ester to 

 0-ester and react with different velocities 

 because the various salts have different 

 values for Kj, Kg and Kg. 



(5) The value of K3 is not changed ap- 

 preciably by a change in temperature and 

 therefore the ratio of N-ester to 0-ester is 

 not changed. But the values of K^ and 

 K,, on the one hand, and of Ktrans. and 

 K'trans., ou the othcr hand, are altered 

 practically alike and hence the velocities 

 of formation of both N-ester and 0-ester 

 have about the same temperature coeffi- 

 cients as other similar reactions. 



(c) A change in solvent may cause a 

 change in Kj, Kg and Kg, and hence cause 

 a change in the ratio of N-ester to 0-ester. 



{d) The same salt and different alkyl 

 halides yield different ratios of esters, be- 

 cause Ktrans. and K'trans. differ for the 

 different alkyl halides (see g). 



(e) A change in the concentration of the 

 salt and the allq^l halide does not appre- 

 ciably change the ratio of the N-ester to 

 the 0-ester because there is no appreciable 

 change in the ratio of the ions from the two 

 salts. 



(/) The addition of another salt with the 

 same cation produces no appreciable change 

 in the ratio of the N-ester to the 0-ester 

 obtained from a given salt and an alkyl 

 halide, because the degrees of ionization of 

 both tautomeric salts are suppressed prac- 

 tically alike. 



{g) The alkyl halide reacts with the 

 anion; but the alkyl halide does not seem 

 to react appreciably through (1) primary 

 dissociation into alkyl and halide ions, as 

 was assumed by Bruyn and Steger, nor 

 (2) through the union of the alkyl halide 

 with the cation and the formation of a 

 complex cation which then reacts with the 

 anion, as was assumed by Euler, nor (3) 

 through a preliminary dissociation into a' 

 halogen hydride and an unsaturated al- 



kylene or alkylidene residue, as was as- 

 sumed by Nef. But mathematical reason- 

 ing alone led us to the conclusion that the 

 alkyl halide may unite to a small extent 

 with the urazole anion and form a complex 

 anion which then yields the ester and the 

 halide ion. A fundamental part of this 

 problem is: (1) to determine experiment- 

 ally the relation of the amount of the free 

 energy of the different isomeric alkyl 

 halides to their equilibrium constants when 

 they change into each other; (2) to connect 

 this with the constants expressing the for- 

 mation of the complex anions by the union 

 of each alkyl halide with the urazole anion, 

 and the velocity of transformation of the 

 complex anions; and (3) to harmonize this 

 with the amount of free energy, and equi- 

 librium constants, of the corresponding 

 isomeric urazole esters which rearrange 

 into each other. In general, whenever an 

 alkyl halide (w-propyl bromide, m-butyl 

 bromide, isobutyl bromide) changes re- 

 versibly nearly completely into another one 

 (isopropyl bromide, secondary butyl bro- 

 mide, tertiary butyl bromide, respectively), 

 as Aronstein and Gustavson have found, 

 then the former alkyl halide reacts far 

 more rapidly with the urazole salts than 

 does the alkyl halide which is formed by 

 such a reversible rearrangement. We shall 

 study this particular problem by the use of 

 thermodynamics. 

 An-f K-f anj ?=* Att.aHjI-fK ^ AnC:H,-f-I-|-K. 



This complex anion theory has now been 

 accepted by others and has been put on a 

 firm basis by the isolation of several double 

 compounds, such as AgNOg-ICHjCN, which 

 seem to have all the properties demanded 

 by the theory. 



Another problem of interest to us is the 

 study of the action of acids, or alkalies, and 

 water on amides, hydrazides, semicarba- 

 zides, oximes, esters, etc. According to 

 our theory the hydrolysis of these sub- 



