Disparity in piezofluorochromism for twisted mono-carbazole-based AIEgens resulting from interchanging electron-rich substituents: effect of coplanarity on twisted π-conjugates

Abstract

Carbazole-based aggregation-induced emission- active fluorogens (AIEgens) with piezo-fluochromic (PFC) features have enhanced the scope of wide variety of applications in the field of optical recording and security display. However, ambiguity...

Small Electron-Rich Isomeric Solid-State Emitters with Variation in Coplanarity and Molecular Packings: Rapid and Ultralow Recognition of TNT

“…Hence, the promising detection efficiency for both of these molecules could be due to noticeably higher void space for both of them [TMBπCBZ (624.4 Å 3 ) and CBZπTMB (328.5 Å 3 )]. 25 However, these molecules do not differ much in terms of molecular size, measured as ∼19 Å (long axis) and ∼7 Å (short axis) (calculated from X-ray structure). Notably, the coplanar CBZπTMB possesses a lower void space as it packs in the crystal lattice much better than more twisted TMBπCBZ molecules.…”

“…To provide a better insight into this different behavior, the available void space would perhaps carry an essential role as it can hold the TNT molecules very much closer for efficient and fruitful interactions with the probe. Hence, the promising detection efficiency for both of these molecules could be due to noticeably higher void space for both of them [TMBπCBZ (624.4 Å 3 ) and CBZπTMB (328.5 Å 3 )] . However, these molecules do not differ much in terms of molecular size, measured as ∼19 Å (long axis) and ∼7 Å (short axis) (calculated from X-ray structure).…”

“…Of note, probes A and B could detect TNT because they come nearer to the quasi-planar carbazole moiety, not with TMB core, indicating a role of planarity . Thus, we integrated TMB with carbazole-linked anthracenyl π-conjugates (TMBπCBZ) and exchanged the position between TMB and CBZ to afford a more planar system CBZπTMB, mainly created by H-bonding . These compounds are identified with the admirable capability to detect TNT in both solutions, solid and vapor states.…”

“…22 Thus, we integrated TMB with carbazolelinked anthracenyl π-conjugates (TMBπCBZ) and exchanged the position between TMB and CBZ to afford a more planar system CBZπTMB, mainly created by H-bonding. 25 These compounds are identified with the admirable capability to detect TNT in both solutions, solid and vapor states. More planar system CBZπTMB exhibits a slightly better TNTdetection feature.…”

Concentration-Guided Visual Detection of Multiphase Aliphatic Biogenic Amines through Amine–Phenol Recognition Using a Dual-State Emitter

“…Earlier investigation on emission tuning directed by phenol–amine interactions in solution was inadequate. , Still, biogenic amine–phenol interactions resulting in FL switching for multiphase recognition of selective aliphatic BAs in ultralow concentration are hitherto unexplored. Moreover, purely organophosphonate-based dual-state emitters are considerably rare. , Typically, we deliver multiple solid-state emitters via Horner–Wadsworth–Emmons reactions with suitable phosphonates as precursors. − In contrast, the precursor phosphonate molecule itself is designed to emit in both solution and the solid state strongly and offers a unique approach to detect BAs selectively at an ultralow concentration in the liquid and concentration-controlled detection of BAs (especially 1,3-diaminopropane, 1,3-DAP) in the vapor phase. Primarily, 1,3-DAP (itself not a biogenic amine but considered an analog of BAs) is formed by the oxidation of spermidine and spermine, a crucial BA responsible for diverse physiological processes, including cellular metabolism in all eukaryotic cells …”