Functional Perovskite Hybrid of Polyacetylene Ammonium and Lead Bromide:  Synthesis, Light Emission, and Fluorescence Imagining

Abstract

A highly photoresponsive perovskite hybrid containing an electroactive organic component (H1) was fabricated. A disubstituted polyacetylene (PA) with a hidden amino functionality (P3) was synthesized, hydrolysis and quaternization of which afforded the desired PA ammonium salt (P5). Mixing P5 with lead bromide readily yielded H1, which was stable, soluble, and film-forming. The inorganic framework induced the polymer chains to align in an ordered fashion, which helped to populate the chain segments with long conjugation lengths. The hybrid emitted a blue light (457 nm) in a high quantum yield (62%), thanks to the enhanced electronic conjugation, the weakened interaction between the layer-segregated chains, and the efficient energy transfer from the inorganic sheets to the organic layers. P3 exhibited a half-discharge time as short as approximately 0.7 s, representing the first example of an efficient photoconductive disubstituted PA. While stable to normal light illumination, H1 was rapidly bleached upon exposure to high-power UV irradiation, enabling facile generation of two-dimensional luminescent photopatterns. After the UV irradiation, the emissions of P9 and P9/H12 were enhanced and weakened, respectively, proving that the inorganic perovskite framework works as a photocatalyst for accelerating the bleaching process of the conjugated PA chains.

Post-functionalization of disubstituted polyacetylenes via click chemistry

“…The substituted PAs have been found to show photoconductivity, optical nonlinearity, magnetic susceptibility, photo-and electroluminescence, liquid crystallinity, biocompatibility, chain helicity, and so on , indicating the bright prospect of the substituted PAs. Generally, disubstituted PAs are superior to their monosubstituted counterparts in performance [15][16][17][18][19][20][21][22][23]. However, the molecular functionalization of disubstituted PAs is difficult [2,3].…”

“…However, the molecular functionalization of disubstituted PAs is difficult [2,3]. Up to now, disubstituted acetylenes with limited types of functional moieties [15][16][17][18][19][20][21][22][23] have been obtained, and apparently it still remains a daunting challenge to polymerize disubstituted acetylenes bearing reactive groups with active protons or coordinative ligands which would readily deactivate the brittle transition-metal catalysts for acetylene polymerizations. There is no doubt that new synthetic methods need to be explored for preparing the functional disubstituted PAs.…”

“…Masuda and coworkers, Tang and coworkers have done some contribution in this area [15][16][17][18][19][20][21][22][23]26]. However, the exploration has never desisted.…”

Synthesis and Functionality of Substituted Polyacetylenes

“…Similarly, functional perovskite hybrid 60 generated between PA ammonium 52 and PbBr 2 shows a better photoconduction result than its parent polymer 52 (Scheme 1.6) [22]. The PC performance of the photoreceptor of 52 is poor, as evidenced by its high T 1/2 (10 seconds) and low S (9.1 mm 2 mW −1 s −1 ) values.…”

“…47 and 37e can undergo nucleophilic substitution and hydrolysis reactions, respectively, to provide imidazole-and carboxy-functionalized disubstituted PAs 50 and 37a [20,21]. Deprotection of imide 36(9) yields amine 51, which can further be ionized by hydrobromic acid to give polycation 52 [22,23].…”