Pyridine nitrogen position controlled molecular packing and stimuli-responsive solid-state fluorescence switching: supramolecular complexation facilitated turn-on fluorescence

Abstract

Fluorophore structure and supramolecular interactions plays important role on the molecular conformation and packing in the solid state that strongly influenced on the solid-state fluorescence properties. Herein, we report the...

Supramolecular Interactions‐Assisted Polymorphism and Unique Mechanofluorochromism in 9,10‐Bis((E)‐4‐(trifluoromethyl)styryl)anthracene

“…On grinding, the loose molecular packing induced by the twisted conformation of the luminogen was completely destroyed. This promotes the molecular conjugation via planarization of the twisted geometry which ultimately leads to red shifted emission (λ max =531 nm) with broadening of the peak [38] (Figure 7a). The intense sharp crystalline peaks in the PXRD pattern of 4FDSA were completely destroyed upon grinding which denotes the transformation of crystalline phase to amorphous state on grinding (Figure 8a).…”

Hexagon and network structured organic geometrical isomers with distinct intramolecular H-bonding and stimuli-induced self-reversible fluorescence switching

“…[15][16][17][18] The subtleness of supramolecular interactions and reversible conformational/ phase changes of fluorescent materials under external stimuli such as mechanical pressure, light and temperature result in reversible fluorescence switching. [19][20][21][22] Molecular engineering of fluorophore structures with different functional groups, including alkyl chains, and hydroxy and amine groups, enhances fluorescence responses along with improving material attributes. [23][24][25] Introducing intramolecular H-bonding functionalities in the molecular structure can induce the excited state intramolecular proton transfer (ESIPT) process and produce molecular fluorescent materials with excellent photophysical properties such as a large Stokes shift (6000-12 000 cm −1 ), dual emission and environmental sensitivity.…”

Distinct fluorescence state, mechanofluorochromism of terpyridine conjugated fluorophores and the reusable sensing of nitroaromatics in aqueous medium

“…[46][47][48] In addition, the nitrogen heteroatom in fluorophores can be employed to demonstrate pH dependent fluorescence switching. [49][50][51][52][53][54] Herein, we intended to study the impact of structural assembly by integrating TPA (propellor), TPE (twisted) and Py (planar) aromatic donor units with a planar terpyridine acceptor (Scheme 1) on the structural assembly in the solid state and fluorescence properties. The structural analysis revealed helical, isolated dimer and continuous aromatic stacking formation in the crystal lattice which resulted in LE, CT state and excimeric tunable solid-state fluorescence as well as distinct mechanical pressure induced fluorescence switching.…”