A microporous metal-organic framework 1, Cu(R-GLA-Me)(4,4'-Bipy)(0.5)center dot 0.55H(2)O (R-GLA-Me = R-2-methylglutarate, 4,4'-Bipy = 4,4'-bipyridine), with a primitive cubic net was synthesized and characterized. With pores of about 2.8 x 3.6 angstrom, the activated 1a exhibits exclusive adsorption of water over methanol in a binary water-methanol (1:1) liquid mixture.