Synthesis and Characterization of Cu/Pr Heterometallic Coordination Polymer

Abstract

A new coordination polymer having hetero metal atoms with mixed ligands has been conveniently synthesized and characterized. Isonicotinic acid (linker) and oxalate ligands were successfully employed to coordinate Pr and Cu within the same metal-organic frame work (MOF). HSAB theory has been implemented to link the transition metals like Cu (soft Lewis acid) to the lanthanides like Pr (hard Lewis acid) through isonicotinic acid which has two different coordination sites. Nitrogen being soft base easily bonds to Cu while oxygen being hard base easily bonds to Pr. Compound 1, [PrCu(C6H4NO2)2(C2O4)]·H2O has been synthesized in this way in a respectable yield. Compound 1 crystallizes in monoclinic crystal system, C2/c space group having three-dimensional crystal lattice. Cu has 1+ oxidation state and the crystals have orange yellow color. An important feature of the compound is the formation of double bridges between two Pr atoms through the oxygen atoms of isonicotinic acid. Formation of such bridges and involvement of Cu in the Pr network would have potential applications towards the magnetic behavior of the coordination polymers