New porous metal-organic coordination polymers (CPs) were synthesized by condensation of 4,5-imidazole dicarboxylic acid ligand (L) with Mo(III), W(VI), Ce(III), Sm(III), and Sn(IV) metal ions. Synthesized complexes were successfully characterized by elemental analysis, FT-IR, H-1 NMR, LC-MS, ICP-MS. Gas storage and adsorption properties of these complexes were investigated via BET measurements after calculating micro-meso pore volume of the complexes. Sorption property of N-2 was performed at temperature of 77 K and pressure of 0.6 bar. Observations depicted that the size of pore was "meso" and the specific surface area determined from nitrogen adsorption was 90 m(2) g(-1). On the other hand, BET measurements indicated that all of these complexes were capable of occluding optimal amount of gas. In general, hydrogen-storage behavior of the synthesized complexes showed a higher surface area and larger pore volumes in which L1Sm had more storage capacity due to its larger surface area and pore size than others. The amounts of hydrogen adsorbed at 298 K and 200 bar reached approximately value of 2.85 wt.%. (C) 2015 Elsevier B.V. All rights reserved.