Rationally Designed Micropores within a Metal−Organic Framework for Selective Sorption of Gas Molecules

A microporous metal−organic framework, MOF, Cu(FMA)(4,4'-Bpe)_0.5 (3a, FMA = fumarate; 4,4'-Bpe = 4,4’-Bpe = trans-bis(4-pyridyl)ethylene) was rationally designed from a primitive cubic net whose pores are tuned by double framework interpenetration. With pore cavities of about 3.6 Å, which are interconnected by pore windows of 2.0 × 3.2 Å, 3a shows highly selective sorption behaviors of gas molecules.