Oligonuclear ferrocenolato and 1,1′-ferrocenediolato derivatives of phosphorus:: synthesis, structure and electrochemical behaviour

Starting from 1,1'-ferrocenediol, fc(OH)(2), several 1,3-dioxa-2-phospha-[3]ferrocenophanes such as [fcO(2)]P(O)R (R = Cl (1), Ph (2), Fc (3), OFc (4)) and fc(OP[O(2)fc])2 (5) were synthesized, and both tri(ferrocenyl)phosphite and tri(ferrocenyl)phosphate, P(OFc)(3) (6) and P(O)(OFc)(3) (7), were obtained starting from ferrocenol, Fc-OH. The new complexes 1-7 were characterized by a consistent set of H-1, C-13 and P-31 NMR spectroscopic data, and the molecular geometry of 7 was determined by an X-ray crystal structure determination. Electrochemical studies indicate that 3 and 4 are oxidized in two consecutive steps; the formation of the monocations, [3](+) and [4](+), is reversible, and the dication [4](2+) is quite stable. The trimetallic compounds 5-7 undergo two nearly overlapping anodic processes to give the corresponding trications. (C) 1998 Elsevier Science S.A. All rights reserved.