Structure of Cobalt Hexaamine Complexes

Numerical data obtained from X-ray crystallographic analysis on the structure of many of the complexes discussed in this section are listed in Table I. 

The simplest complex in this review is the [CofNHale] ion. In the Co(III) state the mean Co-N bond length is 1.960(6) A (in the [Hg(CN)5] salt) ill). The complex in the solid state is slightly distorted from an octahedral array of ligating atoms by crystal packing forces. The cobaltous ion has mean Co-N bond lengths of 2.183(2) A (PFe salt) (12) and 2.160(5) A (Cl salt) (13). 

The structure of the hexakis complex of NH2OH has also been reported recently (14). In contrast to the methylamine complex the mean 

Co-N bond length is similar to that of the hexaamine complex at 1.958 A, despite the greater steric hindrance due to the hydroxo group as compared to a proton. 

Complex Co-N (A) Chelate bite angle (degrees) Trigonal twist, rf) (degrees) Reference 

---