Structure and g Tensor Orientation of the (Tetraphenylporphyrinato)iron(III) Bis(benzenethiolate) Anion

Article abstract of DOI:10.1021/ja00400a025

Single-crystal X-ray and ESR investigations of the potassium 18-crown-6 salt of (tetraphenylporphyrinato)iron(III) bis(benzenethiolate) have provided a detailed eletronic characterization of a low-spin bis(thiolato)iron(III) porphyrin.The structural analysis at 115 K yielded Fe-N distances of 2.013(4) and 2.003(4) Angstroem and Fe-S distance of 2.336(2) Angstroem, characteristic of a low-spin Fe(III) complex.Principal g values of /g_x/ = 1.964, /g_y/ = 2.213, and /g_z/ = 2.337 correspond closely to orientation of the magnetic field along the short Fe-N vector, the long Fe-N vector, and the normal to the porphyrin plane, respectively.Both the X-ray and ESR results are consistent with partial occupation of an iron d_yz orbital which interacts in a ? fashion with filled sulfur p orbitals of the thiolate ligands.