A New Dinuclear Cd(II) Macrocyclic Complex of a Schiff Base Ligand: Synthesis, Characterization, NMR and Mass Spectroscopy Investigation and Ab Initio Calculations

Abstract

In this paper we report the synthesis and characterization of a novel binuclear Cd(II) macrocyclic Schiff base complex [{CdL_22pydfp}₂NO₃](ClO₄)₃. [2+2] cyclocondensation of L_22py = N-(2-pyridylmethyl)-N-(2-aminoethyl)-1,2-diaminoethane and 2,6-diformyl-4-methylphenol, dfp, in the presence of Cd(NO₃)₂·4H₂O in equimolar ratios gave a new macrocylclic complex. Resulting complex was characterized by NMR, IR spectroscopy, elemental analysis and mass spectrometry. The result of mass spectrum shows that above complex is binuclear. The observed isotopic patterns appeared in mass spectrum is confirmed with calculated patterns. In addition, a theoretical study at DFT (B3LYP) level using standard 6-31+G(d) basis sets for ligand atoms and –21G for metals showed that pyridine rings are in the most stable geometrical isomer trans position. All bond lengths and angles were obtained from above theoretical calculations. We found that the bond lengths are in normal range.