Cage Polycyclic Hydrocarbons Based on Adducts of Norbornadiene-2,5 and Anthracene Derivatives

Dibenzomethanopentacene‐Based Polymers of Intrinsic Microporosity for Use in Gas‐Separation Membranes

“…The 1 : 1 anthracene/norbornadiene adduct, first reported in 1975, [13] is a well‐studied monomer for the preparation of high glass transition temperature polymers using ring‐opening‐metathesis‐polymerisation (ROMP) [14] . In contrast, the 2 : 1 adduct, given here the abbreviated name dibenzomethanopentacene (DBMP), was reported only recently [15] . It is worth noting an earlier observation of an unidentified “white solid”, which was removed from the crude product of the 1 : 1 adduct was almost certainly DBMP [14a] .…”

“…For example, 1 H NMR signals for the methylene hydrogens of DBMP are found at a highly shielded position (δ H = À 1.0 ppm) due to the presence of the ring current of adjacent benzo units . [15] Therefore, this methylene bridge is likely to act as a wedge to ensure structural rigidity (Scheme 1). DBMP also possesses a large rigid cleft and other cavities, that provide intermolecular free volume similar to those of triptycene, [16] which is the structural unit for most upper bound performing PIMs.…”

“…The structure of DBMP has several features that make it an attractive component for making PIMs. For example, 1 H NMR signals for the methylene hydrogens of DBMP are found at a highly shielded position ( δ H =−1.0 ppm) due to the presence of the ring current of adjacent benzo units [15] . Therefore, this methylene bridge is likely to act as a wedge to ensure structural rigidity (Scheme 1).…”

“…[14] In contrast, the 2 : 1 adduct, given here the abbreviated name dibenzomethanopentacene (DBMP), was reported only recently. [15] It is worth noting an earlier observation of an unidentified "white solid", which was removed from the crude product of the 1 : 1 adduct was almost certainly DBMP. [14a] The structure of DBMP has several features that make it an attractive component for making PIMs.…”