Characterization and electrochemical study of bis(ferrocenes) with a furanspacer and ferrocenophanes prepared from alpha-bromoacetyl substituted ferrocenes

The bis(ferrocene) derivative 3-bromo-2,4-bis(ferrocenyl)furan (3) was prep ared from alpha -bromoacetylferrocene (1) by basic treatment. The heterotri metallic complex 7 containing two ferrocene moieties and Pd(II) was synthes ized by oxidative addition of 3 with a zerovalent palladium precursor. Thes e stable solids were characterized throroughly by spectroscopic means and e lectrochemical methods (CV and DPV). The new [4]-ferrocenophane (8), with a ll sp(2)C bridges was prepared easily from 1,1'-bis(alpha -bromoacetyl)ferr ocene (2) by treatment with K'BuO whereas the reaction with Na2S provides a mixture of 3-thia-[5]ferrocenophane (9), as the major product, and [5,5]fe rrocenophane (10), as the minor product. (C) 2001 Elsevier Science B.V. All rights reserved.