Dynamics of Water Molecules in a 3-Fold Interpenetrated Hydrogen-Bonded Organic Framework Based on Tetrakis(4-pyridyl)methane

Abstract

The 3-fold interpenetration of the β-quartz-type hydrogen-bonded organic framework (HOF) from the dication salts of tetrakis­(4-pyridyl)­methane develops a host–guest system featuring flexibility and durability in accordance with the state change of guest molecules. Water molecules are incorporated into HOF and form a one-dimensional helical-shaped molecular chain in nanopores. X-ray crystallographic analysis and the dielectric dispersion in the impedance measurements revealed that guest water molecules behave dynamically and show a concerted freezing process to produce water pentamers at 100 K. Structural changes in the host framework mediate interactions between guest water molecules within and between the nanopores through the weak host–guest interactions based on hydrogen-bonding interaction. In addition, the triangular arrangement of nanopores gives rise to the topologically unsettled guest molecules in the freezing process.

A Chiral Bis‐Naphthylated Tetrandrine Dibromide: Synthesis, Self‐Assembly into an Organic Framework Based On Nanosized Spherical Cages, and Inclusion Studies

“…They have the advantage of being soluble in most common solvents and in some cases they show an assembly-disassembly behaviour, making them useful for a wide range of applications. [6][7][8][9][10][11][12][13] Crystalline organic supramolecular assemblies can be classified in two groups: POFs, being porous infinite networks of organic molecules interconnected through non-covalent interactions, forming a solid-state material; and POCs, which are materials with discrete pores and cavities assembled by organic tectons only. 3 In this regard, Davis' group has reported a series of POFs consisting in chiral steroidal ureas assembled through hydrogen bonds with unit cell volumes in the range of 8,053-8,636 Å 3 .…”

“…Molecular crystals are usually maintained by stronger intermolecular interactions such as hydrogen bonds or electrostatic forces. [8][9][10][14][15][16][17][18][19][20][21][22][23][34][35][36][37][38] The methanol content in DNT-MeOH ( Figure S6, Supporting Information) was estimated from the number of diffuse electrons determined by the SQUEEZE routine [39] within the solvent accessible voids, after eliminating the contribution of the bromide anions (96 × 36 e). The determined electrons correspond to approx.…”

“…Purely organic structures assembled by non‐covalent interactions are also known. They have the advantage of being soluble in most common solvents and in some cases they show an assembly‐disassembly behaviour, making them useful for a wide range of applications . Crystalline organic supramolecular assemblies can be classified in two groups: POFs, being porous infinite networks of organic molecules interconnected through non‐covalent interactions, forming a solid‐state material; and POCs, which are materials with discrete pores and cavities assembled by organic tectons only.…”

“…According to the literature, this assembly might be the largest among the purely synthetic organic molecular crystals reported to date, since the unit cell has dimensions comparable to that of proteins with a size of about 50 kDa. Molecular crystals are usually maintained by stronger intermolecular interactions such as hydrogen bonds or electrostatic forces …”

Crystal Engineering of a Tetraphenol with Bispyridines toward Hydrogen-Bonded Emissive Cocrystals

“…The quartz structure consists of tetrahedral silicon bonded with ditopic oxygen with a relaxed tetrahedral angle. Although not prevalent, a few organic crystals and cocrystals are known to adopt a qtz topology through noncovalent interactions. − Any network aiming to mimic quartz should ideally consist of four- and two-connecting building blocks of tetrahedral symmetry and required bent angles, respectively. The average D 2 h -symmetric THPBPE, in two symmetry-independent conformations, stretches into adopting a pseudotetrahedral geometry.…”