Structural, magnetic and electronic characterization of an isostructural series of dinuclear complexes of 3d metal ions bridged by tpbd

Dinuclear complexes of the type [{M(H2O)(phen)}2(μ-tpbd)](ClO4)4 with N,N,N′,N′-Tetrakis-(2-pyridylmethyl)-benzene-1,4-diamine (tpbd) as bridging ligand and M = Mn(II) (1), Fe(II) (2), Co(II) (3), Ni(II) (4), Cu(II) (5), Zn(II) (6) were synthesized, structurally analyzed and their magnetic as well as their electrochemical properties are determined. A ligand-centered one-electron oxidation leads to radical complexes for which the lifetimes are strongly dependent on the coordinated metal ion as followed from time-resolved UV–Vis absorption spectroscopy. In addition to the six homometallic dinuclear complexes, one analog heterometallic Mn(II)/Ni(II) compound (7) of the same constitution was structurally and magnetically investigated, confirming an high spin ground state.

Dinuclear complexes of the type [{M(H2O)(phen)}2(μ-TPBD)](ClO4)4 with N,N,N′,N′-Tetrakis-(2-pyridylmethyl)-benzene-1,4-diamine (tpbd) as bridging ligand and M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) were synthesized, structurally analyzed and their magnetic as well as their electrochemical properties are determined. A ligand-centered one-electron oxidation leads to radical complexes for which the lifetimes are strongly dependent on the coordinated metal ion as followed from time-resolved UV–Vis absorption spectroscopy. One analog heterometallic Mn(II)/Ni(II) compound was structurally and magnetically investigated, confirming a high spin ground state.Figure optionsDownload as PowerPoint slideHighlight
► An isostructural series of dinuclear complexes of Mn, Fe, Co, Ni, Cu, and Zn ions bridged by tpbd is synthesized.
► The bridging ligand tpbd has an extended conjugated pi-system and is easily oxidized to its radical form.
► Magnetic and electrochemical properties were studied for all complexes.