Stereochemical and Equilibrium Data

The energy-difference calculation between kkk and k k k for D-(Coen3)3+ only accounts for the nonbonded interactions between the atoms and, as pointed out by Corey and Bailar (5), takes no account of hydration-energy differences between the two forms. The latter may be significant, and there 

As with the carbocyclic systems, the hydrogens on both N and C adopt axial and equatorial positions, and in the change from one conformer to the other the axial H inverts to the equatorial position and vice versa. There are many examples of ring systems in coordination chemistry which can adopt these conformational isomeric positions. Four systems currently being studied are the complexes of 1,2-propylenediamine, 1,2-f/ww-cyclo-hexanediamine, 1,2-fraw.y-cyclopentanediamine, and 2,3-butanediamine, and some reference will be made to each of these. 

The absolute configuration of the ions in a crystal of l-(—)-[Co-(-)-pn3]Br3 has recently been determined (14) the methyl groups were found to be all cis, and the chelate groups were arranged in the mirror-image form to those in D-( + )-(Coen3)3+. 

It has been suggested that there is a possibility of both cis and tram 

The ratio of the equilibrium concentrations of the pairs of optical isomers as each ethylenediamine in (Coen3)3+ is replaced by ( — )-propylenediamine is given in Table I. The specificity resulting from each replacement is readily 

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