The oxalate phosphites are chemical compounds containing oxalate and phosphiteanions. They are also called oxalatophosphites or phosphite oxalates. Oxalate phosphates can form metal organic framework compounds.
The oxalate ion is rectangular and planar. The phosphite ion is shaped as a triangular pyramid. Because of high charge and stiff shape they will bridge across more than one cation, in particular those hard cations with a higher charge such as +3. Hydrogen can convert some of the oxygen on the anions to OH and reduce the charge. Many oxalate phosphite compounds have microporous structures where amines direct the structure formation.[3]
^Chakrabarti, Sandip; Green, Mark A.; Natarajan, Srinivasan (March 2002). "Hydrothermal synthesis of the first iron arsenate-oxalate [C4N2H12]2[Fe4(HAsO4)6( C2O4)2], possessing open architecture". Solid State Sciences. 4 (3): 405–412. Bibcode:2002SSSci...4..405C. doi:10.1016/S1293-2558(02)01268-2.