Five-coordinate iron carbonyl complexes with fluorocarbon-bridged ligands

Article abstract of DOI:10.1021/ic50077a019

The fluorocarbon-bridged di(tertiary phosphines) ffos and f₆fos react with iron pentacarbonyl to yield the compounds ffosFe(CO)₃, ffosFe(CO)₄, and f₆fosFe(CO)₃. A related di(tertiary arsine) gives ffarsFe(CO)₄ and ffarsFe₂(CO)₈. The Fe(CO)₃ compounds have C_2v symmetry and the structures are probably based on a distorted trigonal bipyramid with equatorial-equatorial substitution. The ligands act, respectively, as monodentate and bridging groups in the Fe(CO)₄ and Fe₂(CO)₈ compounds. The M?ssbauer spectra of these and related compounds show little variation in isomer shift. However it seems that the M?ssbauer quadrupole splittings can be used to distinguish between cis- and trans-disubstituted derivatives of a trigonal-bipyramidal iron(0) complex. Other spectroscopic data for these compounds are given. In particular the carbonyl infrared spectra show some interesting features.