Spectroscopic investigation of chalcone-analogous ferrocenes ortho-substituted in the aromatic ring : II. FerrocenylCOCHCHaryl-type compounds

Abstract

Chalcone-analogous ferrocenes of the type FcCOCHCHAr, ortho-substituted in the aromatic ring were prepared. Their conformations and electron distributions were investigated by cyclic voltammetry, IR, 1H and 13C NMR spectroscopy. The spectroscopic properties measured for this series were compared with those of para-subsituted analogues and with data for structural isomers synthesized and studied earlier and having the aryl and ferrocenyl groups bonded to the enone moiety in reversed positions (FcCHCHCOAr). In contrast with the isomers investigated earlier, the new series are coplanar and the S- cis → S-trans conformational equilibria are shifted in favour of the former.