Crystal structure of NH_4[(CH_3)_2NH_2]_2[Ta(C_2O_4)]∙ 2.5H_2O

In the rational synthesis of novel materials the oxalate anion has appeared as a useful bridging ligand in constructing a diversity of homo and heterometallic compounds with attractive new architectures and interesting properties. A very frequently used approach for the synthesis of polynuclear oxalate-bridged species consists in using stable mononuclear anionic oxalate complexes as ligands toward the second metal ion - the approach known as "complexes as ligands" or "building-blocks chemistry".