A Stable Sulfonato–Cobalt(III) Complex: Δ‐[Co{OS(O)2CH2CH2NH2‐N,O}(en)2](ClO4)2

A stable sulfonato complex, (2-aminoethanesulfonato-N,O)bis(ethylenediamine-N,N')cobalt(III) perchlorate, [Co(C 2 H 6 NO 3 S)(C 2 H 8 N 2 ) 2 ](ClO 4 ) 2 , was prepared by oxidation of [Co{OS(O)CH 2 CH 2 NH 2 -N,O}(en) 2 ] 2+ (en = NH 2 CH 2 CH 2 NH 2 ) in acid media. This sulfonato complex was resolved by SP-Sephadex column chromatography and the absolute configuration of the slower eluted (-)589-isomer was determined by X-ray analysis to be Δ.