Two imidazolate-metal based rhombic dodecahedra (termed MOP-100 and MOP-101) were designed and prepared from [(NH3)(4)Pd(NO3)(2)] and hydrogen tetrakis(1-imidazolyl)borate or hydrogen tetrakis(4-methyl-1-imidazolyl)borate in a concentrated ammonium hydroxide solution at 85 degrees C. Both rhombic dodecahedra show unusual chemical stability in acidic and basic solutions as well as common organic solvents. Permanent porosity was examined by gas adsorption studies. From the N-2, isotherm for MOP-101, the Langmuir and BET surface areas of MOP-101 were calculated to be 350 and 280 m(2) g(-1), respectively. Anion exchange experiments confirmed the internal cavities of such polyhedra are accessible.