Holding Open Micropores with Water: Hydrogen-Bonded Networks Supported by Hexaaquachromium(III) Cations

Abstract

A hydrogen-bonded solid has pores sustained by complementary interactions between hexaaqua metal cations and phosphonate anions. The pores are templated by guest molecules of a certain size and chemical functionality, but these guests are removable. Even though the activated form of the solid is 27% water by weight, reversible gas sorption is demonstrated. The framework shows adaptability to different guest species.

Taming nitroformate through encapsulation with nitrogen-rich hydrogen-bonded organic frameworks

“…3 and 4) [5][6][7][12][13][14][15][16] . Although the density of HOF-NF is lower than most modern energetic compounds [38][39][40] , it has one of the highest densities reported for HOFs so far [19][20][21][22][23][24][25][26][27][28] . This is because (1) the pores, which are filled with NF1 and NF2, occupy about 17% of the volume of the unit cell, which is lower than most of the occupancy of pores among reported HOFs; and (2) the introduction of the highly dense NF.…”

“…Hydrogen-bonded organic frameworks (HOFs) are an emerging class of materials, which are constructed by self-assembly of organic building units through intermolecular hydrogen bonds (H-bonds) and have shown a greater potential in gas storage, chemical separation, and catalysis [19][20][21] . Contrary to MOFs and COFs (covalent organic frameworks), HOFs are easily prepared, their structure can be easily elucidated using single-crystal X-ray diffraction, the starting materials are readily found, and their regeneration processes are low energy-consuming 22,23 .…”

Hybrid Hydrogen‐Bonded Organic Frameworks: Structures and Functional Applications

“…However, a hybrid HOF with 1D channels can be formed once the sulfonate oxygen atoms coordinate with metal and can keep crystalline after solvents removing [58] . Shimizu's group utilized bisphosphonate ligands and [Cr(H 2 O) 6 ] 3+ cations to construct a pillared‐layer structures through hydrogen bonds between water protons and acetone carbonyl group as well as phosphonate groups [59] . After mildly removing acetones, they obtained a porous structure that showed structural change under high CO 2 pressure.…”

Supramolecular encapsulation of hexaaquacobalt(ii) cations in a hydrogen-bonded framework for slow magnetic relaxation and high proton conduction

“…S2, ESI †), which is exceptionally high for a H-bonded structure. 18 The VT-PXRD patterns reveal a strong and sharp peak in the vicinity of 8.9°(Fig. S3, ESI †), generally a hallmark of high crystallinity.…”