A C₃-symmetric macrocycle-based, hydrogen-bonded, multiporous hexagonal network as a motif of porous molecular crystals

A C₃-symmetric π-conjugated macrocycle combined with an appropriate hydrogen bonding module (phenylene triangle) allowed the construction of crystalline supramolecular frameworks with a cavity volume of up to 58 %. The frameworks were obtained through non-interpenetrated stacking of a hexagonal sheet possessing three kinds of pores with different sizes and shapes. The activated porous material absorbed CO₂ up to 96 cm³ g-¹ at 195 K under 1 atm.This is the accepted version of the following article: Hisaki I., Nakagawa S., Tohnai N., et al. A C₃-symmetric macrocycle-based, hydrogen-bonded, multiporous hexagonal network as a motif of porous molecular crystals. Angewandte Chemie - International Edition 54, 3008 (2015), which has been published in final form at https://doi.org/10.1002/anie.201411438.[Link to final article]. This article may be used for non-commercialpurposes in accordance with the Wiley Self-ArchivingPolicy [https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html

Docking Strategy To Construct Thermostable, Single-Crystalline, Hydrogen-Bonded Organic Framework with High Surface Area

Enhancing thermal and chemical durability and increasing surface area are two main directions for the construction and improvement of the performance of porous hydrogen-bonded organic frameworks (HOFs). Herein, a hexaazatriphenylene (HAT) derivative that possesses six carboxyaryl groups serves as a suitable building block for the systematic construction of thermally and chemically durable HOFs with high surface area through shape-fitted docking between the HAT cores and interpenetrated three-dimensional network. A HAT derivative with carboxybiphenyl groups forms a stable single-crystalline porous HOF that displays protic solvent durability, even in concentrated HCl, heat resistance up to 305 °C, and a high Brunauer–Emmett–Teller surface area [SA(BET)] of 1288 m2 g−1. A single crystal of this HOF displays anisotropic fluorescence, which suggests that it would be applicable to polarized emitters based on robust functional porous materials.This is the accepted version of the following article: Hisaki I., Suzuki Y., Gomez E., et al. Docking Strategy To Construct Thermostable, Single-Crystalline, Hydrogen-Bonded Organic Framework with High Surface Area. Angewandte Chemie - International Edition 57, 12650 (2018), which has been published in final form at https://doi.org/10.1002/anie.201805472. This article may be used for non-commercialpurposes in accordance with the Wiley Self-ArchivingPolicy [https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html

Conformationally-flexible and moderately electron-donating units-installed D–A–D triad enabling multicolor-changing mechanochromic luminescence, TADF and room-temperature phosphorescence

A novel twisted donor–acceptor–donor (D–A–D) π-conjugated compound that contains flexible and moderately-electron-donating units has been designed and synthesized. It exhibited not only multi-color-changing mechanochromic luminescence and thermally activated delayed fluorescence, but also, unexpectedly, room-temperature phosphorescence in a host layer

Acid Responsive Hydrogen-Bonded Organic Frameworks

A porous hydrogen-bonded organic framework (HOF) responsive to acid was constructed from a hexaazatrinaphthylene derivative with carboxyphenyl groups (CPHATN). Precise structures of both 1,2,4-trichlorobenzene solvate [CPHATN-1(TCB)] and activated HOF with permanent porosity (CPHATN-1a) were successfully determined by single-crystalline X-ray diffraction analysis. Permanent porosity of CPHATN-1a was evaluated by gas sorption experiments at low temperature. CPHATN-1a also shows significant thermal stability up to 633 K. Its crystals exhibit a rich photochemistry thanks to intramolecular charge-transfer and interunit proton-transfer reactions. Femtosecond (fs) experiments on crystals demonstrate that these events occur in ≤200 fs and 1.2 ps, respectively. Moreover, single-crystal fluorescence microscopy reveals a shift of the emission spectra most probably as a result of defects and a high anisotropic behavior, reflecting an ordered crystalline structure with a preferential orientation of the molecular dipole moments. Remarkably, CPHATN-1a, as a result of the protonation of pyradyl nitrogen atoms embedded in its π-conjugated core, shows reversible vapor acid-induced color changes from yellow to reddish-brown, which can be also followed by an ON/OFF of its emission. To the best of our knowledge, this is the first HOF that exhibits acid-responsive color changes. The present work provides new findings for developing stimuli responsive HOFs.Hisaki I., Suzuki Y., Gomez E., et al. Acid Responsive Hydrogen-Bonded Organic Frameworks. Journal of the American Chemical Society. 141(5), 2111-2121, (2019), 6 February 2019; © 2019 American Chemical Society. https://doi.org/10.1021/jacs.8b12124

Positional Effects of Annelated Pyrazine Rings on Structure and Stability of Hydrogen-Bonded Frameworks of Hexaazatrinaphthylene Derivatives

A porous hydrogen-bonded organic framework (HOF) composed of N-hetero pi-conjugated molecules (N pi-HOF) is a promising candidate for multifunctional porous materials. However, such HOFs are still limited and only a handful of examples have been reported. In this study, we investigated the positional effects of annelated pyrazine rings on the structure and stability of N pi-HOFs to establish a design principle for N pi-HOFs. A new isomer of hexaazatrinaphthylene (CPBTQ) was synthesized and subjected to N pi-HOF construction, activation, and an evaluation of stability and permanent porosity. A comparison between two kinds of N pi-HOFs composed of isomers (CPBTQ and CPHATN) possessing three pyrazine rings annelated at different positions indicates that the positional difference of the pyrazine rings strongly affects the conformation of the peripheral phenylene groups, which then leads to different structures and stabilities of the N pi-HOFs. The activated N pi-HOF composed of CPBTQ (CPBTQ-1a) is revealed to exhibit a Brunauer-Emmett-Teller surface area of 471 m(2) g(-1) and shows HCl responsiveness thanks to the basic pyrazine rings annelated to the triphenylene core. We believe that the present results can contribute not only to the construction of multifunctional porous materials but also to the chemistry of heteroaromatic compounds

Generation of Supramolecular Chirality around Twofold Rotational or Helical Axes in Crystalline Assemblies of Achiral Components

A multi-point approximation method clarifies supramolecular chirality of twofold rotational or helical assemblies as well as bundles of the one-dimensional (1D) assemblies. While one-point approximation of materials claims no chirality generation of such assemblies, multi-point approximations do claim possible generation in the 1D assemblies of bars and plates. Such chirality derives from deformations toward three-axial directions around the helical axes. The chiral columns are bundled in chiral ways through symmetry operations. The preferable right- or left-handed columns are bundled together to yield chiral crystals with right- or left-handedness, respectively, indicating that twofold helix symmetry operations cause chiral crystals composed of achiral components via a three-stepwise and three-directional process

A C₃-symmetric macrocycle-based, hydrogen-bonded, multiporous hexagonal network as a motif of porous molecular crystals

This is the accepted version of the following article: Hisaki I., Nakagawa S., Tohnai N., et al. A C₃-symmetric macrocycle-based, hydrogen-bonded, multiporous hexagonal network as a motif of porous molecular crystals. Angewandte Chemie - International Edition 54, 3008 (2015), which has been published in final form at https://doi.org/10.1002/anie.201411438.[Link to final article]. This article may be used for non-commercialpurposes in accordance with the Wiley Self-ArchivingPolicy [https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html]A C₃-symmetric π-conjugated macrocycle combined with an appropriate hydrogen bonding module (phenylene triangle) allowed the construction of crystalline supramolecular frameworks with a cavity volume of up to 58 %. The frameworks were obtained through non-interpenetrated stacking of a hexagonal sheet possessing three kinds of pores with different sizes and shapes. The activated porous material absorbed CO₂ up to 96 cm³ g-¹ at 195 K under 1 atm