Synthesis and crystal structure of Mn(II) complexes with novel macrocyclic Schiff-base ligands containing piperazine moiety

A series of Mn(II) macrocyclic Schiff-base complexes [MnL(n)Cl](+) (n = 1-4) have been prepared via the Mn(II) templated [1+1] cyclocondensation of 2,6-diacetylpyridine or 2,6-pyridinedicarbaldehyde with the symmetrical 1,4-bis(3-aminopropyl)piperazine or the novel asymmetrical N,N'(2-aminoethyl)(3-aminopropyl)piperazine linear amines containing piperazine moiety. The complexes have been characterized by elemental analyses, IR, FAB-MS, magnetic studies and conductivity measurements. The crystal structure of [MnL(2)(CH(3)OH)CI](ClO(4)) and [MnL(4)Cl](PF(6)) complexes have also been determined showing the metal ion in a N(4)OCl pentagonal bipyramidal or N(4)Cl highly distorted octahedral geometry, respectively. (C) 2008 Elsevier Ltd. All rights reserved.