# What is the geometry of an ML_2X_2 complex?

If $M {L}_{2} {X}_{2}$ is tetrahedral, all the metal ligand positions are equivalent. Should the complex be square planar, the chelating oxalato ligand can ONLY span cis -positions, to give a cis metal complex. For the trans complex, the oxalato ligand would join up metal centres (with the elimination of $A g C l$!) to give oligomers and polymers.