Carbon-13 spectra of 2-hetera[3](1,1′)ferrocenophanes

The analysis of the ¹³C FT NMR spectra of 2-hetera[3](1,1′)ferrocenophanes containing an oxygen, sulphur, selenium atom, phenyl-substituted nitrogen or a methylene group in the 2-position of the bridge has been carried out. The electronegativity of this fragment affects both chemical shifts and coupling constants, but no simple relationship was found.