Formation and stabilization of five-coordinate iron(II) verdoheme analogues by axial weakly coordinating anion ligation. X-ray crystal structures of [(OEOPFe)2O](X)2 (X=AsF6, SbF6)
摘要:
The effect of weakly coordinating anions, AsF6- and SbF6-, as axial ligands on the formation and coordination chemistry of verdoheme analogues have been examined. Two new five-coordinate and stable iron(II) verdoheme analogues, [(OEOPFeX)-X-II], where OEOP is the monoanion of octaethyloxoporphyrin and X = AsF6 and SbF6, have been isolated. The compounds have been characterized by different spectroscopic methods as well as elemental analysis. H-1 NMR spectroscopy and magnetic moment measurements show that the [(OEOPFeX)-X-II] are paramagnetic and iron is five-coordinate. Exposure of dichloromethane solutions of [(OEOPFeX)-X-II] (X = AsF6 (2), SbF6 (3)) to dioxygen result in their transformation into the mu-oxo bridged compounds, [(OEOPFe)(2)O](X)(2) (X = AsF6 (4), SbF6 (5)). The structures of 4 and 5 have been determined by X-ray diffraction analysis, both are structurally similar with a P2(1)/c space group in the monoclinic crystal system. (C) 2006 Elsevier B.V. All rights reserved.
Formation and stabilization of five-coordinate iron(II) verdoheme analogues by axial weakly coordinating anion ligation. X-ray crystal structures of [(OEOPFe)2O](X)2 (X=AsF6, SbF6)
摘要:
The effect of weakly coordinating anions, AsF6- and SbF6-, as axial ligands on the formation and coordination chemistry of verdoheme analogues have been examined. Two new five-coordinate and stable iron(II) verdoheme analogues, [(OEOPFeX)-X-II], where OEOP is the monoanion of octaethyloxoporphyrin and X = AsF6 and SbF6, have been isolated. The compounds have been characterized by different spectroscopic methods as well as elemental analysis. H-1 NMR spectroscopy and magnetic moment measurements show that the [(OEOPFeX)-X-II] are paramagnetic and iron is five-coordinate. Exposure of dichloromethane solutions of [(OEOPFeX)-X-II] (X = AsF6 (2), SbF6 (3)) to dioxygen result in their transformation into the mu-oxo bridged compounds, [(OEOPFe)(2)O](X)(2) (X = AsF6 (4), SbF6 (5)). The structures of 4 and 5 have been determined by X-ray diffraction analysis, both are structurally similar with a P2(1)/c space group in the monoclinic crystal system. (C) 2006 Elsevier B.V. All rights reserved.