A series of nanosized cavity-containing bipyrazolate-bridged metallomacrocycles with dimetal centers, namely, {[(bpy)M](8)L-4}(NO3)(8) [L = 3,3',5,5'-tetramethyl-4,4'-bipyrazolyl, Pd 1, Pt 2; 1,4-bis-4'-(3',5'-dimethyl)-pyrazolylbenzene) Pd 5; and 1, 4-bis-4'-(3', 5'-dimethyl)-pyrazolyl biphenyl, Pd 9], {[(phen)M](8)L-4}(NO3)(8) [L = 3,3',5,5'-tetramethyl-4,4'bipyrazolyl, Pd 3, Pt 4; 1,4-bis-4'-(3',5'-dimethyl)-pyrazolylbenzene, Pd 7; and 1,4-bis-4'-(3',5'-dimethyl)-pyrazolylbiphenyl, Pd 11], {[(bpy)Pd](6)L-3}(NO3)(6) [L = 1, 4-bis-4'- (3', 5'-dimethyl)-pyrazolyl benzene, 6, 10], {[(phen)-Pd](6)L-3}(NO3)(6) [L = 1,4-bis-4'-(3',5'-dimethyl)-pyrazolylbenzene, 8, 12], {[(bpy)Pd](4)L-2}(NO3)(4) [L = 1,3-bis-4'-(3',5'-dimethyl)-pyrazolylbenzene, 13, and 1,2-bis-4'-(3',5'-dimethyl)-pyrazolylbenzene, 15], and {[(phen)Pd14L2}(NO3)(4) [L = 1,3-bis-4'-(3',5'-dimethyl)-pyrazolylbenzene, 14, and 1, 2-bis-4'-(3', 5'-dimethyl)-pyrazolyl benzene, 16] (where bpy = 2,2'-bipyridine and phen = 1,10-phenanthroline) have been synthesized through a directed self-assembly approach that involves spontaneous deprotonation of the 1H-bipyrazolyl ligands in aqueous solution. These complexes, with weak Pd(II)center dot center dot center dot Pd(II) or Pt(II)center dot center dot center dot Pt(II) interactions, have been characterized by elemental analysis, H-1 and C-13 NMR, cold-spray ionization or electrospray ionization mass spectrometry, UV-visible spectroscopy, and luminescence spectroscopy. Complexes 1, 3, 5, 6, 14, and 15 have also been characterized by single-crystal X-ray diffraction analysis.