Syntheses, Characterization and Crystal Structure of Two Manganese (III) Complexes with Ligand N,N'-Ethylenebis(1-phenyl-3-imino-1-butanone)

Two manganese (I) complexes with the ligand bzacen2- [bzacen2- =N, N'-ethylenebis(1-phenyl-3-imino-1-butanone)], Mn(bzacen) (NO2) (EtOH) (1) and Mn(bzacen) (NO2) (MeOH) (2), have been synthesized and characterized by IR, electronic spectra and cyclic voltammetry. Both complexes crystallize in the orthorhombic system, space group Pbca, with parameters for complex 1: a=2. 817 3(6) nm, b=2. 194 6(4) nm, c=0. 768 3(6) nm, V=4. 750(5) nm3, Z=8, μ=5. 71 cm-1, and with parameters for complex 2: a=2. 764 1(6) nm, b=2.183 2(4) nm, c=0. 770 5(2) nm, V=4. 650(3) nm3, Z=8, μ=5. 81 cm-1. The final R values are 0. 054 0 for complex 1 and 0. 056 4 for complex 2, respectively. The structure determination of the title complexes reveals an octahedral coordination with an N2O2 equatorial plane composed of the donor atoms from the Schiff base ligand bzacen2-. In these complexes, vC=N, vC=O and vC=C care shifted to lower frequencies in IR spectra; π-π* transitions, d-π* charge-transitions and d-d* ligand field transitions are observed in their electronic spectra.