title: Dichloro(4,10-dimethyl-1,4,7,10-tetraazabicyclo[5.5.2]tetradecane)iron(III) hexafluorophosphate.
abstract: The title compound, [FeCl2(C12H26N4)]PF6, is the first mononuclear Fe3+ complex of an ethylene cross-bridged tetraaza-macrocycle to be structurally characterized. Comparison with the mononuclear Fe2+ complex of the same ligand shows that the smaller Fe3+ ion is more fully encapsulated by the cavity of the bicyclic ligand. Comparison with the mu-oxo dinuclear complex of an unsubstituted ligand of the same size demonstrates that the methyl groups of 4,10-dimethyl-1,4,7,10-tetraazabicyclo[5.5.2]tetradecane prevent dimerization upon oxidation of the metal centre. Nax -Fe3+ -Nax bond angles (ax is axial), and thus the degree of encapsulation by the ligand, are quite different between the mononuclear and dinuclear mu-oxo species, which is probably the consequence of steric considerations.
authors.affiliation: Department of Chemistry and Physics, Southwestern Oklahoma State University, Weatherford, OK 73096, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: McClain
authors.forename: Danny L
authors.initials: DL
authors.lastname: Maples
authors.forename: Randall D
authors.initials: RD
authors.lastname: Maples
authors.forename: Dallas L
authors.initials: DL
authors.lastname: Matz
authors.forename: Sebastian M
authors.initials: SM
authors.lastname: Harris
authors.forename: Andrew D L
authors.initials: AD
authors.lastname: Nelson
authors.forename: Jon D
authors.initials: JD
authors.lastname: Silversides
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Archibald
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Hubin