Two types of luminescent cyclic metallomacrocycles containing Re(I)-2,2'-bpy MLCT chromophores and diphosphine bridges (P-P) have been prepared by self-assembly. The "petite squares" are tetramers based on trans-cis-Re(CO)(2)(P-P)(2)(bpy) units, while the "grand rings" are octamers composed of alternating Re(CO)(2)(P-P)(2)(bpy) and Re(CO)(3)(P-P)(2)Cl units. Complete structural assignment of the former, but not the latter, was accomplished using IR and NMR spectroscopies as well as by mass spectrometry.