The Co-3(CO)(9)C moiety acts as an electroreducible marker for estradiol detection enhancement in the HPLC-ED technique

The tricobalt enneacarbonyl-ethynylestradiol derivative Co-3(CO)(9)C-C=C-E (E = estradiol) proved to be elusive, due to the strong electron-withdrawing properties of both the 17 beta OH and the Co-3(CO)(9)C groups. However, the advantage of introducing the Co3C core, which undergoes a reversible I e reduction, can be achieved by the interposition of a spacer arm, namely -C(O)NHC6H4-, generated in situ during the synthesis in the appropriate experimental conditions. The corresponding bioorganometallic product Co-3(CO)(9)C-C(O)NHC6H4-C=C-E retains an acceptable relative binding affinity for estradiol receptor affording a new electrochemical marker suitable for biochemical analyses. (C) 2000 Elsevier Science S.A. All rights reserved.