Different behavior of PDA as a preorganized ligand versus PCA ligand in constructing two inorganic-organic hybrid materials based on Keggin-type polyoxometalate

A preorganized dicarboxylic acid ligand (PDA) in reaction with Keggin-type polyoxometalate and lanthanoid clusters creates a 3-D coordination polymer in which the Keggin counterpart acts as a bi-dentate inorganic ligand. In contrast, in similar reaction conditions, a monocarboxylic acid ligand (PCA) leads to the formation of distinct dimeric units of Keggin-type polyoxometalate and lanthanoid clusters.