Triptycene-Based Organic Molecules of Intrinsic Microporosity

Abstract

Four Organic Molecules of Intrinsic Microporosity (OMIMs) were prepared by fusing triptycene-based components to a biphenyl core. Due to their rigid molecular structures that cannot pack space efficiently, these OMIMs form amorphous materials with significant microporosity as demonstrated by apparent BET surface areas in the range of 515–702 m2 g–1. Bulky cyclic 1′,2′,3′,4′-tetrahydro-1′,1′,4′,4′-tetramethylbenzo units placed on the triptycene termini are especially efficient at enhancing microporosity.

Synthesis of a Rigid C3v‐Symmetric Tris‐salicylaldehyde as a Precursor for a Highly Porous Molecular Cube

“…Such 1,4‐adducts were first reported by Klanderman35 and recently by McKeown and co‐workers,36 but are still a rare exception in the reaction of arynes and anthracenes 37. Again, this rare cycloaddition can only be explained by frontier orbital controlled regioselectivity, similar to the situation explained above.…”

The Synthesis of Organic Molecules of Intrinsic Microporosity Designed to Frustrate Efficient Molecular Packing

“…[d] Structure previously reported for packing simulation . [e] Structure and experimental data previously reported …”

“…Given its success as a component for making organic microporous materials, triptycene derived arms were also investigated for making OMIMs. Hence, cores 1 and 2 were combined with triptycene‐2,3‐diol ( 5 a ) to give 23 (OMIM‐1) and 28 (OMIM‐10), respectively. Both OMIM‐1 and OMIM‐10 proved to be highly soluble and gave amorphous solids with apparent SA BET of 485 and 423 m 2 g −1 , respectively.…”

“…An investigation to determine the suitability of various rigid structural building units as peripheral arms for OMIM construction was performed by combining catechol derivatives of benzenopentacene ( 6 ) spirobifluorene ( 7 ), propellane ( 8 ), and hexaphenylbenzene ( 9 ) with cores 1 and 2 . Benzenopentacene containing OMIM‐6 and OMIM‐16, were found to possess apparent SA BET in the range 10–15 % lower than their more symmetrical isomeric triptycene‐based counterparts OMIM‐5 and OMIM‐14.…”

“…We are engaged in a joint modelling and synthesis programme to investigate organic molecules of intrinsic microporosity (OMIMs), which we define as discrete molecular compounds that are designed to generate microporous materials solely from their inability to pack efficiently in the solid state. Theory suggests that for both two‐ and three‐dimensional objects, the most inefficient packing is produced when the constituent shapes possess highly concave faces.…”