Hydrogen-Bonded Organic Framework Microlasers with Conformation-Induced Color-Tunable Output

Abstract

Porous organic frameworks have emerged as the promising platforms to construct tunable microlasers. Most of these microlasers are achieved from metal–organic frameworks via meticulously accommodating the laser dyes with the sacrifice of the pore space, yet they often suffer from the obstacles of either relatively limited gain concentration or sophisticated fabrication techniques. Herein, we reported on the first hydrogen-bonded organic framework (HOF) microlasers with color-tunable performance based on conformation-dependent stimulated emissions. Two types of HOF microcrystals with the same gain lumnogen as the building block were synthesized via a temperature-controlled self-assembly method. The distinct frameworks offer different conformations of the gain building block, which lead to great impacts on their conjugation degrees and excited-state processes, resulting in remarkably distinct emission colors (blue and green). Accordingly, blue/green-color lasing actions were achieved in these two types of HOFs based on well-faceted assembled wire-like cavities. These results offer a deep insight on the exploitation of HOF-based miniaturized lasers with desired nanophotonics performances.

Hydrogen-bonded organic frameworks: design, applications, and prospects

“…As hydrogen bond acceptors, cyano groups can connect adjacent building blocks through intermolecular hydrogen bonds to form two kinds of porous framework, termed as HOF-FJU-4 and HOF-FJU-5. 102 In HOF-FJU-4, the building blocks are connected with four neighboring blocks by C-NÁ Á ÁH hydrogen bonds, and the layers are further superimposed along the a-axis via the C-HÁ Á Áp interaction. On the contrary, in HOF-FJU-5, the building blocks are connected with two building block molecules by C-NÁ Á ÁH hydrogen bonds, and the layers are further superimposed along the baxis via C-HÁ Á Áp interaction.…”

“…155,156 Consequently, Zhao and co-workers first reported the application of HOFs in the field of micro-lasers. 102 A tetrastyrene chromophore with significant solid optical gain characteristics was selected as the main chain, and the cyano group was used as a hydrogen bond acceptor. Two kinds of microcrystals, HOF-FJU-4 and HOF-FJU-5, were formed by selfassembly in solution.…”

Hydrogen‐Bonded Organic Frameworks: Functionalized Construction Strategy by Nitrogen‐Containing Functional Group

“…We report the first organic framework microlaser constructed by hydrogen bonding with tunable color properties for excitation emission due to conformational differences. [72] Both materials were constructed from 1,1,2,2-tetra(4-carbonitrile-[1,1'-biphenyl]-4-yl)ethylene. In HOF-FJU-4, the stacked molecules show a herringbone pattern with large spaces, forming a cage-like microstructure through hydrogen bonding with a 12.4 % void ratio of the framework (Figure 12a).…”

“…The flexible block designability and liquid‐phase self‐assembly features of hydrogen‐bonded organic framework sources provide an alternative solution for realizing novel porous organic laser materials. We report the first organic framework microlaser constructed by hydrogen bonding with tunable color properties for excitation emission due to conformational differences [72] . Both materials were constructed from 1,1,2,2‐tetra(4‐carbonitrile‐[1,1’‐biphenyl]‐4‐yl)ethylene.…”

Functionalization of a stable AIE-based hydrogen-bonded organic framework for white light-emitting diodes

“…[1][2][3][4] The variability of the hydrogen bond distance and angle give HOFs unique features compared with other porous crystalline materials, including but not limited to mild synthesis conditions, easy regeneration and high thermal stability. [5][6][7][8][9] Until now, the structural design of HOFs has matured to a point in which the composition, structure, and porosity can be precisely designed [10][11][12] and they show outstanding properties in many elds such as gas separation, [13][14][15][16] sensors, [17][18][19] catalysis, [20][21][22] proton conduction, 23,24 luminescent materials, [25][26][27][28] etc. However, the lack of functional sites limits functional development and performance breakthroughs of HOFs to some extent.…”