Synthesis, spectroscopy and structure of new push-pull ferrocene complexescontaining heteroaromatic rings (thiophene and furan) in the conjugation chain

Six new ferrocene based donor acceptor complexes containing thiophene and f uran in the conjugation chain have been synthesized by conventional methods and characterized by NMR, electronic absorption spectral and electrochemic al methods. X-ray single crystal structures of three thiophene derivatives, [(C5H5)-Fe-(C5H4CH=CH-C4H3S)] (1a), [(C5H5)-Fe-(C5H4-CH=CH-C4H2S-CHO)] (2a ) and [(C5H5)-Fe(C5H4-CH=CH-C4H2S-CH=C(CN)(2))] (3a) have also been determi ned. Electronic absorption spectral and electrochemical studies suggest tha t pi-donor acceptor interactions are facile in thiophene derivatives when c ompared to their benzene analogues. (C) 1999 Elsevier Science S.A. All righ ts reserved.