Nitrito compounds isomerization

Werner knew of two other examples of linkage isomerism, both nitro-nitrito isomers, and they underwent the same period of skepticism and confirmation as the compounds discussed above although considerably less work was done with diem. A period of more than 50 years passed before Basolo and coworkers attacked the problem with rather amazing results.w Linkage isomerism, once relegated to a few lines as an "exceptional" situation in discussions of isomerism, now boasts an extensive chemistry which continues to develop. The first new linkage isomers prepared were mtro-nitnto isomers of Cr lII), Rh(lll), Ir(lll), and Pt(lV). In all cases except Cr(lll), the nitrito isomer converts readily to the more stable nitro isomer... 

This exercise illustrates a rather unusual type of isomerism. Isomeric nitrites and nitro compounds are well known in organic chemistry but are rarely met in inorganic chemistry. However, isomeric nitro- and nitrito-cobaltammines are known and will be prepared here. The starting point is chloropentammine cobaltic chloride, [Co(NH3)eCl]Cl2, prepared in the last experiment. 

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