Synthesis, Crystal Structure, and Photophysical Properties of (1E,3E,5E)‐1,3,4,6‐Tetraarylhexa‐1,3,5‐trienes: A New Class of Fluorophores Exhibiting Aggregation‐Induced Emission

Abstract

Double Horner-Wadsworth-Emmons reaction of (E)-2,3-diaryl-1,4-bis(diethylphosphonyl)but-2-ene with (p-substituted) benzaldehydes gave (1E,3E,5E)-1,3,4,6-tetraarylhexa-1,3,5-trienes in moderate to good yields. Substitution of electron-withdrawing or -donating groups at the para position of the 1,6-diphenyl groups induced a slight bathochromic shift of UV spectra measured in CHCl(3) compared with that of the parent 1,3,4,6-tetraphenylhexa-1,3,5-triene. Although fluorescence was not observed with all the trienes in CHCl(3), they markedly emitted visible light in powder forms with quantum yields of 0.15-0.44. Introduction of amino groups at the para position of the 3,4-diphenyl groups induced a bathochromic shift of emission maxima with good solid-state quantum yields. Thus, the tetraarylated triene framework is found to serve as a new class of fluorophores that exhibit aggregation-induced emission.

Highly Luminescent Inks: Aggregation‐Induced Emission of Copper–Iodine Hybrid Clusters

“…After the ligand exchange reaction, the powder X-ray diffraction (PXRD) patterns indicate that the phase changed (Supporting Information, Figure S1) and the light emission color of the powder turned from yellow to bright blue ( Figure S2a). As we expected, the new compound behaved excellent solubility in organic solvents in comparison to Cu 4 I 4 (py) 4 (Figure S2b,c). To clear illustrate the crystal structure of this new Cu-I hybrid, the obtained powder sample was recrystallized ( Figure S3a-h) and the single crystal X-ray diffraction analysis (Table S1) indicates ac ubic unit cell with the I " 43d space group and the lattice of 31.67 ,i nw hich the isolated Cu 4 I 4 (P-(m-Tol) 3 ) 4 hybrid cluster is composed of the core cubane structure with four copper atoms and four iodine atoms at the corners and four P-(m-Tol) 3 ligands coordinated to each copper atom by the Cu-P bonds ( Figure S3i and Figure 1a).…”

“…Furthermore,wecan synthesizeaseries of AIE inks with different light-emission colors to cover the whole visible spectrum range via af acile ligand exchange processes.T he assemblies of Cu-I hybrid clusters with AIE characteristics will pave the way to fabricate low-cost highly luminescent inks.Aggregation-Induced emission (AIE) luminescent materials have attracted considerable attention in recent years because their light-emitting behaviors are very different to those of conventional luminophores. [1] Since the AIE phenomenon was first reported by Tang et al in 2001, [2] tremendous advances have been made for exploring new types of AIE luminescent materials [3] such as hydrocarbon AIE, [4] heteroatom-containing AIE, [5] macromolecular AIE, [6] and metalcomplex AIE luminescent materials. [7] In particular,aseries of noble metal complexes,s uch as Au I , [8] Pt II , [9] Ag I , [10] and Ir III[11] complexes with AIE effect have been reported in recent years.…”

“…Abstract: Aggregation-induced emission (AIE) is an attractive phenomenon in which materials displaystrong luminescence in the aggregated solid states rather than in the conventional dissolved molecular states.H owever,h ighly luminescent inks based on AIE are hard to be obtained because of the difficulty in finely controlling the crystallinity of AIE materials at nanoscale.H erein, we report the preparation of highly luminescent inks via oil-in-water microemulsion induced aggregation of Cu-I hybrid clusters based on the highly soluble copper iodide-tris(3-methylphenyl)phosphine (Cu 4 I 4 -(P-(m-Tol) 3 ) 4 )hybrid. Furthermore,wecan synthesizeaseries of AIE inks with different light-emission colors to cover the whole visible spectrum range via af acile ligand exchange processes.T he assemblies of Cu-I hybrid clusters with AIE characteristics will pave the way to fabricate low-cost highly luminescent inks.…”

“…To further monitor the aggregation process of Cu 4 I 4 (P-(m-Tol) 3 ) 4 hybrid clusters,t he PXRD patterns and PL spectra of samples during the organic solvent evaporation process were recorded. Initially,t he PXRD pattern of the product obtained after 10 minutes vacuum assisted evaporation process (Figure 2a)s hows very weak diffraction peaks indicating the amorphous state of as-formed nanoscale aggregates.T hen the vacuum-treated emulsion solution was placed under ambient condition to track the crystalline process of Cu 4 I 4 (P-(m-Tol) 3 ) 4 .W ith prolonged time (up to 3days), the intensity of the PXRD peaks of products gradually increased indicating the slow crystallization process (Figure 2a). TheP L spectra were collected every two minutes during the vacuum operation and ag radual increase of photoluminescent intensity was observed.…”

Fluorescence properties of novel 6-butyl-2,3-dicyano-7-methyl-6H-1,4-diazepine styryl dyes containing ethyleneglycol units

“…We serendipitously found the different fluorescence behavior of oily derivatives from solid ones. Meanwhile, aggregation-induced emission enhancement (AIEE) has been reported not only for siloles 2 and tetraarylethylenes 3 but also for dyes, such as BODIPY, 4 4-dicyanomethylene-2,6-distyryl-4H-pyrans, 5 polyenes, 6 and Sudan II. 7 Therefore, it is of significance to find new AIEE dyes.…”