title: Models for the lower S states of photosystem II: a trinuclear mixed-valent MnII/MnIV/MnII complex.
abstract: The trinuclear complex Mn(3)(pko)(4)(CH(3)O)(2)(SCN)(2).CH(3)OH, 1, where Hpko is 2,2'-dipyridylketonoxime, is a rare example of a complex simultaneously containing Mn(II) and Mn(IV). X-ray crystallography and XANES spectroscopy clearly distinguish the Mn(II)(2)Mn(IV) valence isomer from the more commonly observed Mn(III)(2)Mn(II) formulation. Fits to variable-temperature magnetic susceptibility data indicate that the Mn(II) and Mn(IV) are ferromagnetically coupled (J = +6.13 cm(-1)) and that 1 has an S = (13)/(2) ground state.
authors.affiliation: Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, 54124, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Alexiou
authors.forename: Catherine
authors.initials: C
authors.lastname: Dendrinou-Samara
authors.forename: Anastasia
authors.initials: A
authors.lastname: Karagianni
authors.forename: Subhashis
authors.initials: S
authors.lastname: Biswas
authors.forename: Curtis M
authors.initials: CM
authors.lastname: Zaleski
authors.forename: Jeff
authors.initials: J
authors.lastname: Kampf
authors.forename: Derek
authors.initials: D
authors.lastname: Yoder
authors.forename: James E
authors.initials: JE
authors.lastname: Penner-Hahn
authors.forename: Vincent L
authors.initials: VL
authors.lastname: Pecoraro
authors.forename: Dimitris P
authors.initials: DP
authors.lastname: Kessissoglou
mesh_terms: D018360:Crystallography, X-Ray; D007501:Iron / Q000737:chemistry*; D008280:Magnetics; D008345:Manganese / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D045332:Photosystem II Protein Complex; D013057:Spectrum Analysis
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D008345:Manganese; D007501:Iron; D010100:Oxygen