title: Bis(cyano) Iron(III) Porphyrinates: What Is the Ground State?
abstract: The synthesis of six new bis(cyano) iron(III) porphyrinate derivatives is reported. The anionic porphyrin complexes utilized tetraphenylporphyrin, tetramesitylporphyrin, and tetratolylporphyrin as the porphyrin ligand. The potassium salts of Kryptofix-222 and 18-C-6 were used as the cations. These complexes have been characterized by X-ray structure analysis, solid-state Mössbauer spectroscopy, and EPR spectroscopy, both in frozen CH2Cl2 solution and in the microcrystalline state. These data show that these anionic complexes can exist in either the (dxz,dyz)(4)(dxy)(1) or the (dxy)(2)(dxz,dyz)(3) electronic configuration and some can clearly readily interconvert. This is a reflection that these two states can be very close in energy. In addition to the effects of varying the porphyrin ligand, subtle effects of the cyanide ligand environment in the solid state and in solution are sufficient to shift the balance between the two electronic states.
authors.affiliation: †College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, YanQi Lake, HuaiRou District, Beijing 101408, China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Li
authors.affiliation: ‡Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Bruce C
authors.initials: BC
authors.lastname: Noll
authors.affiliation: §Department of Physics, Knox College, Galesburg, Illinois 61401, United States.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Schulz
authors.affiliation: ‡Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: W Robert
authors.initials: WR
authors.lastname: Scheidt
mesh_terms: D018360:Crystallography, X-Ray; D003486:Cyanides / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D015394:Molecular Structure; D011166:Porphyrins / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D003486:Cyanides; D011166:Porphyrins; C409084:tetraphenylporphyrin; D007501:Iron