Self-Recognizing π-π Stacking Interactions Designed for the Generation of Ultrastable Mesoporous Hydrogen-Bonded Organic Frameworks

Abstract

Creating crystalline porous materials with large pores is typically challenging due to undesired interpen-etration, staggered stacking, or weakened framework stability. Here, we report a pore size expansion strategy by self-recognizing π-π stacking interactions in a series of two-dimensional (2D) hydrogen–bonded organic frameworks (HOFs), HOF-10x (x=0,1,2), self-assembled from pyrene-based tectons with systematic elongation of π-conjugated molecular arms. This strategy successfully avoids interpene-tration or staggered stacking and expands the pore size of HOF materials to access mesoporous HOF-102, which features a surface area of ~ 2,500 m2/g and the largest pore volume (1.3 cm3/g) to date among all reported HOFs. More importantly, HOF-102 shows significantly enhanced thermal and chemical stability as evidenced by powder x-ray diffraction and N2 isotherms after treatments in chal-lenging conditions. Such stability enables the adsorption of dyes and cytochrome c from aqueous media by HOF-102 and affords a processible HOF-102/fiber composite for the efficient photochemical detox-ification of a mustard gas simulant.

Emerging Porous Materials and Their Composites for NH3 Gas Removal

“…Li and co‐workers reported pyrene‐based HOFs (HOF‐100, HOF‐101, and HOF‐102) with mesoporosity. [ 104 ] HOF‐100, HOF‐101, and HOF‐101 were formed by 1,3,6,8‐tetracarboxy pyrene, 1,3,6,8‐tetrakis ( p ‐benzoic acid), and 1,3,6,8‐tetra(6‐carboxynaphthalene‐2‐yl) pyrene, respectively, through myriad hydrogen bonds between the carboxylic dimers and layer stacking by strong π – π interactions. In the case of HOF‐101, its crystal structure was evaluated using the single‐crystal X‐ray diffraction method, and the other structures were determined via molecular modeling.…”