Metal-organic framework materials are of great interest because of their potential applications in catalysis, gas sensing and storage etc. These materials are constructed of metal centers connected through organic ligands which can then form extended multi-dimensional topologies. By placing the donor group in a phenyl substituted heteroscorpionate in a para or meta position rather than an ortho arrangement we change the ligand from a facially coordinating tripodal one favoring mononuclear complexes, into one capable of bridging interactions possibly leading to multidimensional MOF structures.

To this end, using our standard synthetic methodology, we have now prepared several new ligands that have either OH or COOH groups located on the meta or para positions of the aromatic ring. Reaction of the p-carboxylate ligand designated L4c in MeOH with aqueous solutions of divalent metals such as Cu(II) show that the primary species formed is a 2:2 dimer as characterized by X-ray crystallography.