Benzene‐Templated Hydrothermal Synthesis of Metal–Organic Frameworks with Selective Sorption Properties

In this paper, we report two metal–organic frameworks [Co 3 (ndc) 3 (bipyen) 1.5 ] ⋅ H 2 O ( 1 ) and [Co 2 (ndc) 2 (bipyen)] ⋅ C 6 H 6 ⋅ H 2 O ( 2 ) (bipyen= trans ‐1,2‐bis(4‐pyridyl)ethylene, H 2 ndc=2,6‐naphthalenedicarboxylic acid). These compounds were both synthesized from identical hydrothermal reaction conditions except that benzene was added to the reaction for 2 . Crystal structures show that the two compounds have triply interpenetrated three‐dimensional frameworks and these frameworks have the same primary structure of a two‐dimensional network of interconnected [Co 2 (O 2 CR) 4/2 ] (R=naphthalene group) paddle‐wheels and bridging bipyen ligands. Both compounds have guest water molecules and, in addition, 2 has guest benzene molecules. Structural transformations of the host accompanied guest removal, which can be monitored by powder X‐ray diffraction. N 2 adsorption data of 2 show that there are two different types of pores corresponding to the benzene and water pores. Upon exposure to vapors of several organic molecules, the heat‐treated sample of 2 adsorbs benzene and cyclohexene, but does not adsorb toluene, ( o ‐, m ‐, and p ‐)xylenes, cycloheptatriene, or cyclohexane.