MONONUCLEAR AND BINUCLEAR MANGANESE(III) COMPLEXES WITH N,N'-ETHYLENEBIS(1-PHENYL-3-IMINO-1-BUTANONATO) LIGAND - X-RAY CRYSTAL-STRUCTURES OF [MN(BZACEN)(MEOH)(2)](CLO4) AND N-2(BZACEN)(2)(MEOH)(2)](CLO4)(2)CENTER-DOT-2H(2)O

Two manganese(III) complexes with the ligand bzacen(2-) [bzacen(2-) = N,N'-ethylenebis(1- -phenyl-3-imino-1-butanonato)], [Mn(bzacen) (MeOH) (2)]ClO4 (1) and [Mn-2(bzacen)(2)(MeOH)(2)] (ClO4)(2) . 2H(2)O (2), we re prepared and characterised by IR, Raman, UV-vis spectra, cyclic vol tammogram and X-ray diffraction. The coordination geometry around the Mn atoms in these two complexes is distorted octahedral with an equato rial plane N2O2 from the bzacen(2-). The [Mn-2(bzacen)(2)(MeOH)(2)](2) cation in 2 is a centrosymmetric dimer in which two manganese(III) a toms are joined by two ketonic oxygen atoms (Mn-O 1.908 and 2.448 Angs trom), the Mn2O2 core in the dimer being with Mn ... Mn separation of 3.355 Angstrom and Mn-O-Mn angles of 100.0. The vibration frequencies of the unsaturated nu(C=O), nu(C=N) and nu(C=C) are shifted to lower i n IR and Raman spectra. There are pi-pi transitions, d-pi* charge-tra nsfer transitions and d-d transitions in the electronic spectra. Copy right (C) 1996 Elsevier Science Ltd