title: Electronic structure of four-coordinate iron(I) complex supported by a bis(phosphaethenyl)pyridine ligand.
abstract: A 15-electron iron complex with a formal Fe(I) center, [FeBr(BPEP)] (BPEP = 2,6-bis(1-phenyl-2-phosphaethenyl)pyridine), was prepared by one-electron reduction of the dibromide precursor [FeBr(2)(BPEP)]. The single-crystal diffraction analysis revealed a distorted trigonal monopyramidal arrangement around the iron center, and SQUID magnetometry established the S = 3/2 ground state. The Mossbauer isomer shift value (delta = 0.59 mm/s) was consistent with a high-spin Fe(I) center of [FeBr(BPEP)]. DFT calculations for a model complex revealed two highly delocalized molecular orbitals formed by bonding and antibonding interactions between the d(z(2)) (Fe) and pi* (BPEP) orbitals. Orbital occupancy analysis demonstrated the electronic structure with a high-spin Fe(I) center. The effective dpi-ppi interaction between iron and BPEP was concluded to be responsible for the highly distorted structure of [FeBr(BPEP)], with its rather uncommon trigonal monopyramidal configuration.
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nakajima
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Nakao
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Sakaki
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Tamada
authors.forename: Teruo
authors.initials: T
authors.lastname: Ono
authors.forename: Fumiyuki
authors.initials: F
authors.lastname: Ozawa
mesh_terms: D004583:Electrons; D007501:Iron / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D011725:Pyridines; D007501:Iron; C023666:pyridine