Synthesis of metal complexes with a novel ethyldioxolane pendant-arm hexaazamacrocyclic ligand

Abstract

The coordination capability of a pendant-arm azamacrocyclic ligand L with four ethyldioxolane pendant groups towards transition, post-transition and lanthanide metal ions was achieved. In all cases, complexes with a 2:1 metal:ligand molar ratio were obtained. The complexes were characterized by elemental analysis, MS-FAB, IR, conductivity measurements, 1H and 13C NMR spectroscopy. Crystal structures of [CoL][CoBr 0.5(NO 3) 3.5] and [(H 2O)H 2L][Nd(NO 3) 4(H 2O) 3]NO 3·3.5H 2O have been determined. The [CoL] 2+ cation contains the Co(II) ion endomacrocyclicly coordinated in a distorted octahedral geometry with a N 6 core. The Nd(III) complex presents a mononuclear exomacrocyclic structure with an 11 coordination environment. π,π-Stacking interactions have been observed between the pyridine rings of the protonated ligand [(H 2O)H 2L] 2+, and the [Nd(NO 3) 4(H 2O) 3] 2− anion.