Synthesis and Mossbauer Spectra of Octaethylporphyrin Ferrous Complexes
David Dolphin, Sams, J.R., Tsin, T.B., and Wong, K.L.
J. Am. Chem. Soc.
The square planar complex octaethylporphyriniron(II) (1) was prepared as for tetraphenylporphineiron(II) and phthalocyanineiron(II), Fe2+ in 1 is in the intermediate spin (S = 1) state. The hexacoordinate adducts of I with pyridine, NH3, 3- and 4-picoline are all diamagnetic. Moessbauer spectra were measured between 4.2 and 300 oK, and in applied magnetic fields of up to 50 kG. In every case the quadrupole coupling constant is positive and the electric field gradient at Fe is axially symmetric. The nearly temperature-independent quadrupole splitting in I suggests that there are no low-lying excited orbital states in this complex.