Abstract:
Cobalt(III) chloropentammines of the type [Co(en)2(NH2R)Cl]2+ were first prepared by Alfred Werner. A Werner. Ber. 44, 1887 (1911). Werner found that addition of aqueous ammonia to an aqueous solution of trans-dichlorobis(ethylene diamine) cobalt(III)+ led to rapid formation of the chloropentammine [Co(en)2(NH3)C1]2+.
Meisenheimer and Kiderlen J Meisenheimer and H. Kiderlen. Ann. 438, 212 (1924). extended this work and showed that certain primary amines react with either cis- or trans-dichlorobis(ethylenediamine) cobalt (III) chloride in an aqueous medium to form complexes of the general type [Co(en)2(NH2R)Cl]2+. Generally the reactions with trans-[Co(en)2Cl2]Cl proceeded more rapidly than those with the cis- isomer, and also gave better yields of the product.
Bailer and Clapp J. C. Bailer and L. B. Clapp. J. Amer. Chem. Soc. 171 (1945). further extended this work and in agreement with Meisenheimer and Kiderlen found that many primary amines form reasonably stable chloro-amine complexes with both cis- and trans-[Co(en)2Cl2]Cl.
