Synthesis, crystal structure and spectroscopic properties of some cadmium(II) complexes with three polyamine and corresponding macroacyclic Schiff base ligands

摘要

Three Cd( II) macroacyclic Schiff base complexes [CdL4(NO3)(2)] (4), [CdL5( NO3)(2)] (5), [CdL6( NO3)(2)] ( 6) were prepared by template condensation of 2-pyridinecarboxaldehyde with N1-( 2-nitrobenzyl)-N1-( 2-aminoethyl) ethane-1,2-diamine ( L-1), N1-( 2-nitrobenzyl)-N1-( 2-aminoethyl) propane-1,3-diamine ( L-2) or N1-( 2-nitrobenzyl)-N1-( 3-aminopropyl) propane-1,3-diamine ( L-3), in the presence of cadmium metal ion, respectively. Three Cd( II) complexes with L1, L2 and L3 were also synthesized. All complexes have been studied with IR, H-1 NMR, C-13 NMR, DEPT, COSY, HMQC and microanalysis. Two of these complexes, [CdL4( NO3)(2)] ( 4) and [CdL1(NO3)(2)] ( 1) have been characterized through X-ray crystallography. In complex 4, the Cd is in a six-coordinate environment comprised of the ligand N-4-donor set and two oxygen atoms of two nitrate groups. In the polyamine complexes ( 1, 2 and 3) Cd and ligand are in a ratio of 1:1. Supporting ab initio HF-MO calculations have been undertaken using the standard 3-21G* and 6-31G* basis sets. (C) 2008 Elsevier B. V. All rights reserved.