Hexanuclear Lanthanide Clusters Encapsulating a µ < inf > 6 < /inf > -CO < inf > 3 < /inf > < sup > 2− < /sup > Ion Displaying an Unusual Binding Mode

Abstract

Reaction of hydrated lanthanum halides (Ln=La, Pr and Nd) with LH2 [1-(2-HydroxyPhenyl)-3-(2-thienyl)-1,3-Propanedione] in presence of excess triethylamine with methanol as a solvent resulted in the isolation and structural characterization of a series of novel hexanuclear lanthanide clusters templated by µ6-CO32− introduced via spontaneous fixation of atmospheric carbon dioxide depicting a new coordination mode of binding. This particular mode of bridging is a first report of its kind in lanthanide clusters. Magnetic analysis of the praseodymium and neodymium analogue shows strong antiferromagnetic interactions in case of praseodymium and weak antiferromagnetic interactions in case of neodymium.