Rhodium‐ and ruthenium‐complex‐catalyzed condensation of ferrocene‐containing dithiols and diols with diarylsilanes to give silaferrocenophanes and ferrocene polymers

Abstract

Abstract 1,1′‐Ferrocenedithiol reacts with di(4‐methoxyphenyl)silane, diphenylsilane, and di(4‐fluorophenyl)silane in the presence of RhCl(PPh 3 ) 3 catalyst to give mixtures of 2,2‐diaryl‐1,3‐dithia‐2‐sila[3]ferrocenophanes (1a–3a) and (FcSSiAr 2 S) n  (Fc = 1,1′‐ferrocenylene; 1b: Ar = C 6 H 4 OMe‐4; 2b: Ar = Ph; 3b: Ar = C 6 H 4 F‐4). The products are isolated and characterized by NMR spectroscopy and elemental analyses. The polymers 1b–3b, obtained from a toluene‐soluble fraction of the products, show GPC elution patterns corresponding to M n values of 2700–4600 (polystyrene standards). The UV–vis spectra of the ferrocenophanes and polymers exhibit a d–d transition peak at about 440 nm, while the polymers show a π – π * transition peak at 320–330 nm. The cyclic voltammograms of 3a (Ar = C 6 H 4 F − 4) and 3b show a reversible redox of the iron center at 0.27 V and 0.35 V (Ag + /Ag) respectively. Reaction of 1,1′‐ferrocenedimethanol with diphenylsilane in the presence of RuCl 2 (PPh 3 ) 3 catalyst results in selective formation of 3,3‐diphenyl‐2,4‐dioxa‐3‐sila[5]ferrocenophane ( 4 ), whose structure was determined by X‐ray crystallography. Copyright © 2001 John Wiley & Sons, Ltd.