Selective separation using porous adsorbents is an energy-efficient alternative to traditional separation techniques. Stacked porous organic molecular frameworks (POMF) capable of noncovalent π···π interactions are emerging as a new kind of adsorbents that facilitate green separation. Here we report a robust porous molecular crystal ( TAPM-1 ), which is stabilized by multiple intermolecular π···π interactions. With its long-range π-stacking, TAPM-1 has excellent hydrophobicity, thermostability, recyclability, and high selectivity for aromatics over the corresponding cyclic aliphatics. This enables TAPM-1 to serve as the stationary phase in the high-resolution gas chromatographic separation of benzene and cyclohexane or toluene and methylcyclohexane.