文摘
Three porous (3,24)-connected rht-type metal鈥搊rganic frameworks (MOFs), [Cu3L(H2O)3]路xsolvents (H6LOH = 4,4鈥?4鈥?(hydroxysilanetriyl)tris(triphenyl-3,5-dicarboxylic acid), SDU鈥?; H6LMe = 4,4鈥?4鈥?(methylsilanetriyl)tris(triphenyl-3,5-dicarboxylic acid), SDU鈥?; H6LiBu = 4,4鈥?4鈥?(isobutylsilanetriyl)tris(triphenyl-3,5-dicarboxylic acid), SDU鈥?), have been successfully prepared from [Cu2(COO)4] paddlewheel SBUs (secondary building units) and C3-symmetric Si-based hexatopic carboxylatelinkers. All porous MOFs are constructed from 3D packing of nanosized cuboctahedral, truncated tetrahedral, and truncated octahedral cages. SDU鈥?鈥? differ only in the functionality of the central Si atom of the hexacarboxylate ligands with hydroxyl, methyl, and isobutyl groups, respectively. Gas adsorption measurements of activated MOFs suggested that decoration of the cage walls with strong polar groups can enhance the adsorption capacities for N2, H2, and CH4. SDU鈥? with 鈭扥H as the functional group possesses high CH4 uptake (172 cm3 cm鈥? at 35 bar), which is very close to DOE target of 180 cm3 cm鈥?.