title: Ligand-induced distortion of a tetranuclear manganese butterfly complex.
abstract: The reaction of the pentadentate Schiff-base ligand 1,3-bis(salicylideneamino)-2-propanol (salproH3) with [Mn3O(O2CR)6(py)3] (R = Me, Et, But) gives the corresponding tetranuclear manganese product [Mn4O2O2CR)5(salpro)] (4Mn(III)). The syntheses, structure and magnetochemical characterization of these complexes are reported. The structure of the [Mn4(mu3-O)2]8+ is butterfly-like much more closed than in previous complexes with this core as a result of the alkoxide oxygen of the salpro ligand bridging the two wingtip Mn atoms. Variable-temperature, solid-state magnetic susceptibility studies reveal that these complexes possess S = 0 ground state spins. Fitting of the magnetic susceptibility data to the theoretical chiMT vs. T expression derived for a C2v symmetry complex, assuming an isotropic Heisenberg spin-Hamiltonian and using the Van Vleck equation, revealed that the various exchange parameters are all antiferromagnetic, and the core thus experiences spin frustration effects.
authors.affiliation: Department of Chemistry, University Of Florida, Gainesville, FL 32611-7200, USA.
authors.forename: Rashmi
authors.initials: R
authors.lastname: Bagai
authors.forename: Khalil A
authors.initials: KA
authors.lastname: Abboud
authors.forename: George
authors.initials: G
authors.lastname: Christou
mesh_terms: D018360:Crystallography, X-Ray; D007202:Indicators and Reagents; D008024:Ligands; D017895:Manganese Compounds / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D007202:Indicators and Reagents; D008024:Ligands; D017895:Manganese Compounds; D009942:Organometallic Compounds