Synthesis and Characterizations of Star-Shaped Octupolar Triazatruxenes-Based Two-Photon Absorption Chromophores

Abstract

A series of star-shaped octupolar triazatruxenes (TATs, 1-6) with intramolecular "push-pull" structure were synthesized and their photophysical properties have been systematically investigated. These chromophores showed obvious solvatochromic effect, i.e., significant bathochromic shift of the emission spectra and larger Stokes shifts were observed in more polar solvents mainly due to photoinduced intramolecular charge transfer (ICT). The two-photon absorption (2PA) cross-section values were determined by two-photon excited fluorescence (2PEF) measurements in toluene and THF. These chromophores exhibited large two-photon absorption cross-sections ranging from 280 to 1620 GM in the near-infrared (NIR) region. Compound 6 showed the largest 2PA action cross-section (σ(2)Φ) of 564 GM and could be a potential two-photon fluorescent (2PF) probe. In addition, compounds 1-6 all displayed good thermal stability and photostability.

Dopant‐Free Hole Transporting Materials for Perovskite Solar Cells

“…In an extended delocalized π ‐system, three indole units are combined by one benzene ring in triazatruxene. With their electron rich aromatic structure, triazatruxene derivatives has been widely used to produce electroactive discotic liquid crystalline materials, organic‐light‐emitting diodes (OLEDs), and two photon absorption (TPA) materials . In 2015, Ramos et al designed and synthesized two novel triazatruxene core based HTMs, HMDI ( 93 ) and HPDI ( 94 ) to exploit in PSCs .…”

5,6‐Dihydroxyindole Chemistry: Unexplored Opportunities Beyond Eumelanin

“…Clockwise from the top left corner, the list of structures with associated potential functions/applications includes: a) six-armed C 3 -symmetric and asymmetric triazatruxenes (diindolocarbazoles) as planar star-shaped π systems with redox, π stacking, and self-assembling properties of potential interest for light-emitting diodes, batteries and capacitors, electroactive discotic liquid crystals, and selective G-quadruplex ligands, [74,75] b) a 2,7Ј:2Ј,7ЈЈ-triindole and a 2,2Ј-biindole as conformationally flexible tridentate and bidentate metal chelators, c) rod-shaped carboxylated oligoindoles connected at the 4-and 7-positions and forming oligo(p-phenylene)-containing polycarboxylic systems of possible interest as molecular wires, backbones, and rigid spacer units for artificial channels, organic conductors upon doping, and other applications in organoelectronics, d) functionalized 3-thioindole derivatives as central units in compounds with potential biological and pharmacological properties [79][80][81][82] and for the development of glycated derivatives for water-soluble eumelanin-type polymers for biological and technological applications, [55] e) unusual 3-unsubstituted-2-linked diindolylphenylmethanes as ion-sensing agents [83] and pharmacologically useful systems. [84,85] f) alkynyl-bearing π systems amenable to functionalization by acids, click chemistry, and other transformations, potentially convertible into solvatochromic push-pull electronic systems, [58] g) indole-based macrocycles for studies of conformational and self-association properties, stacking interactions, spectroscopic features, cavity shape, and performance as ligands or ion-sensing scaffolds, [86][87][88] and h) 2-(2-amidobenzyl)-3-(indol-3-yl)quinoline as a fluoride sensor.…”

New indole trimers as precursors for molecular electronic materials

“…In this context, we previously reported the formation of 2,3,7,8,12,13-hexabromo-5,10,15-trihydroindolo [3,2-a,3',2'-c]carbazole (1) ( Figure 1, also called hexabromotriazatruxene) by the simple reaction of three equivalents of Br 2 with indole. 5 This represents a straightforward route to a large, conjugated π-system containing readily-substituted Br and N-H groups and has stimulated much subsequent work to prepare a large number of derivatives (Figure 1), [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] studied for their photophysical, liquid crystal and/or charge-transport properties. In particular, such trigonal aromatic molecules offer enhanced opportunities in the formation of dendritic molecules 18,20 or discotic liquid crystalline systems 9 in comparison with linear analogues.…”