Stereoselectivity and Chiral Recognition in the Electron-Transfer Reaction between Spinach Ferredoxin and Optically Active Cobalt(III) Complexes

✍ Scribed by Klaus Bernauer; Michel Monzione; Peter Schürmann; Véronique Viette

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: German
• Weight: 375 KB
• Volume: 73
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19900730214

✦ Synopsis

The kinetics of the electron transfer between reduced spinach [2Fe-2S]-ferredoxin and the optically active complexes [Co((R,R)or (S,S)-alamp)py]+ (I), [Co((R,R)or (S,S)-promp)H20]+ (Ira), and [Co((R,R)-or (S,S)promp)py]+ (IIb) have been investigated. The reactions are stereoselective, and for I and IIa, the stereoselectivity strongly depends on temperature due to large differences in the activation enthalpy between enantiomeric reagents. Isokinetic behaviour is observed between enantiomers, the AAH;-,, values being largely compensated by the ddS,#_, values. The compensation behaviour is explained by the combination of stereochemical interactions and desolvation processes on formation of the precursor complex or the transition state. ') Part XI11 of the series 'Stereoselectivity in Reactions of Metdl Complexes'. For Part XII, see [l].