title: Syntheses, X-ray structures, solid state high-field electron paramagnetic resonance, and density-functional theory investigations on chloro and aqua Mn(II) mononuclear complexes with amino-pyridine pentadentate ligands.
abstract: The two pentadentate amino-pyridine ligands L5(2) and L5(3) (L5(2) and L5(3) stand for the N-methyl-N,N',N'-tris(2-pyridylmethyl)ethane-1,2-diamine and the N-methyl-N,N',N'-tris(2-pyridylmethyl)propane-1,3-diamine, respectively) were used to synthesize four mononuclear Mn(II) complexes, namely [(L5(2))MnCl](PF6) (1(PF6)), [(L5(3))MnCl](PF6) (2(PF6)), [(L5(2))Mn(OH2)](BPh4)2 (3(BPh4)2), and [(L5(3))Mn(OH2)](BPh4)2 (4(BPh4)2). The X-ray diffraction studies revealed different configurations for the ligand L5(n) (n = 2, 3) depending on the sixth exogenous ligand and/or the counterion. Solid state high-field electron paramagnetic resonance spectra were recorded on complexes 1-4 as on previously described mononuclear Mn(II) systems with tetra- or hexadentate amino-pyridine ligands. Positive and negative axial zero-field splitting (ZFS) parameters D were determined whose absolute values ranged from 0.090 to 0.180 cm(-1). Density-functional theory calculations were performed unraveling that, in contrast with chloro systems, the spin-spin and spin-orbit coupling contributions to the D-parameter are comparable for mixed N,O-coordination sphere complexes.
authors.affiliation: Equipe de Chimie Inorganique, Institut de Chimie Moleculaire et des Materiaux d'Orsay, UMR 8182 CNRS, Universite Paris-Sud, 91405 Orsay Cedex, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Hureau
authors.forename: Sihem
authors.initials: S
authors.lastname: Groni
authors.forename: Régis
authors.initials: R
authors.lastname: Guillot
authors.forename: Geneviève
authors.initials: G
authors.lastname: Blondin
authors.forename: Carole
authors.initials: C
authors.lastname: Duboc
authors.forename: Elodie
authors.initials: E
authors.lastname: Anxolabéhère-Mallart
mesh_terms: D002712:Chlorides / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D008024:Ligands; D008345:Manganese / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry*; D011789:Quantum Theory; D014867:Water / Q000737:chemistry*
chemical_list: D002712:Chlorides; D008024:Ligands; D009942:Organometallic Compounds; D011725:Pyridines; D014867:Water; D008345:Manganese; C023666:pyridine