The coordination-driven self-assembly of a series of discrete 2D metallomacrocycles from a rigid diphosphine donor linker and Pd/Pt-containing 90 degrees acceptors is described. All these assemblies are characterized by multinuclear NMR and, in four cases, X-ray crystallography. The selective formation of a diphosphine bridged macrocycle, [(en)Pd(mu-trans-PPh2CHCHPPh2)(2)Pd(en)](4+), from a 1:1:1 mixture of cis-Pd(en)(NO3)(2), trans-Ph2PCHCHPPh2, and 1,2-bis(4-pyridyl)ethane is also established.