266 L. A. NIKOLAEV 



that of the complex with amylamine. For the same reason the complex formed 

 with dimethylamine, in which the copper ion is surrovmded by a large number 

 of methyl groups, has very little activity. However, when a phenyl group is 

 introduced instead of a methyl one the activity is increased if the phenyl group 

 is situated relatively far away from the central ion. Thus the activity of 

 propylamine is 1-5 times that of butylamine. In this case the effect of an increase 

 in mass is only slightly counteracted by steric hindrance. 



A very important feature of the active stnictvure is the formation of rings 

 including the ion-complex combination. This phenomenon accounts for the 

 activity of various chelates of which Martell & Calvin have recendy followed 

 up a whole collection of properties [6]. 



In 1957 the work of Courtney, Gustafson, Westerback, Hyytiainen, Chaberek 

 & Martell was published [7]. While studying the catalytic activity of a large 

 number of complex compounds of transition metals in the reaction of hydrolysis 

 of substituted fluorophosphonic esters, these authors arrived at a similar con- 

 clusion concerning the part played by the formation of rings and emphasized 

 the high activity of compounds of the 'bidentate' type. This is only one of a 

 number of studies in which the authors were aiming at investigating the causal 

 relation between the activity of the complex catalyst and the structure of the 

 addendum. The fact that they drew the same conclusions as we did tends to 

 suggest a more general applicabihty of the rules which we discovered for the 

 catalase process. 



The augmentation of biocatalysts with increase of their mass was remarked 

 on by N. I. Kobozev [8] while developing the theory of 'aggravation' in which 

 he attaches special importance to the combination of a mass, which is not in 

 (thermodynamic) equihbrium, with a particular active group. When this ocoirs 

 the activity, in the examples produced by this author, increases proportionally 

 to the logarithm of the molectdar weight. When a very active structure has been 

 selected further, increase in its activity may be brought about, either by the 

 addition of mass so that the added mass may contribute its share to the activity 

 and this will increase proportionally to the logarithm of the molecular weight, 

 or else by transformation of the structure in such a way that there is a sudden, 

 sharp increase in activity. From our point of view the latter case is of special 

 interest. The activation in the diamine series is a good illustration of this type. 



Special attention must be paid to the fact that, in other cases, an increase in 

 activity is associated with a decrease in the stabihty of the complex compound. 

 The change from ethylenediamine to triethylenediamine is associated with an 

 almost twenty-fold increase in activity while the stabihty of the compound is 

 decreased (Fig. 2). 



The activity increases even more sharply (to 800 times what it was) if di- 

 methyltrimethylenediamine is used as an addendum. This complex serves as a 

 good example of a highly active model structure containing very unstable rings. 



Complexes with trimethylenediamine are easily destroyed by hydrogen 

 peroxide and give results which are hard to reproduce, while hexamethylene- 

 diamine does not form a ring, i.e. only one amino group is included in the sphere 

 of co-ordination, and its activizing effect is correspondingly small (25). It follows 



