ISSN:
1432-1432
Keywords:
Cyanide
;
HCN oligomers
;
Montmorillonite
;
Clays
;
Diaminomaleonitrile (DAMN)
;
Diimi-nosuccinonitrile (DISN)
;
Fe3+
;
Fe2+
;
Primitive Earth
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The previously reported inhibition of the oligomerization of HCN by montmorillonite clays was investigated. The inhibition is due to the oxidation of diaminomaleonitrile (DAMN) by the Fe3+ in the clay lattice. Fe2+ and oxalic acid were shown to be the reaction products. From these reaction products and the previous report that two equivalents of HCN are formed per equivalent ofDAMN, it was established that diiminosuccinonitrile (DISN) is the initial reaction product, which is rapidly hydrolyzed to oxalic acid and HCN. The same oxidative transformations are effected by Fe3+ bound to Dowex 50, Fe3+ in solution and Ni(NH3)6 2+. The rate of reaction of DAMN decreased in the order Fe3+ 〉 Fe3+-Dowex 〉 montmorillonite, indicating no catalytic role for the clay in the oxidation of DAMN. Little reaction of DAMN was observed with montmorillonite in which the bulk of the iron was in the Fe2+ oxidation state. The possible significance of these redox reactions to chemical evolution is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01733896
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