“…In the past few years, there has been considerable effort in designing open-framework structures formed by metal organic carboxylates because of its interesting structural features and the quality for apt design (Fang et al, 2004;Li et al, 2008;Serre et al, 2006;Sun et al, 2006) of which the oxalate ligand plays a major role in the assembly of metal-organic porous frameworks. Many metal oxalate structures are reported such as tin (Audebrand et al, 2001;Kokunov et al, 2004;Stock et al, 2000), zinc (Chakrabarti & Natarajan, 2002;Rvans & Lin, 2001;Vaidhyanathan et al, 2001), zirconium (Audebrand et al, 2004;Gavilan et al, 2007), rare earth (Bataille et al, 2000;Trombe et al, 2001;Yuan et al, 2004). The structures of these compounds vary from monomers, dimmers, chains, layered honeycomb networks to three dimensional frameworks.…”