Using water as the sole solvent, the bifunctional molecule tetrakis(methylthio)-1,4-benzenedi-carboxylic acid (TMBD) was reacted with Cu(CH3CN)(4)BF4 to form a robust microporous metal-organic framework (MOF, CityU-7) featuring Cu(I) ions being simultaneously bonded to the carboxyl and thioether donors. The MOF solid is stable in air and can be easily activated by heating, without the need for treatment with organic solvents. The subnanoscopic pores (ca. 0.6 nm) of the host net allow for uptake of CO2 and H2O but exhibit lesser sorption for N-2 at 77 K. The microporous net can also be penetrated by I-2 molecules.