Aerobic Solid State Red Phosphorescence from Benzobismole Monomers and Patternable Self‐Assembled Block Copolymers

Abstract

The synthesis of the first bismuth‐containing macromolecules that exhibit phosphorescence in the solid state and in the presence of oxygen is reported. These red emissive high molecular weight polymers (>300 kDa) feature benzobismoles appended to a hydrocarbon scaffold, and were built via an efficient ring‐opening metathesis (ROMP) protocol. Moreover, our general procedure readily allows for the formation of cross‐linked networks and block copolymers. Attaining stable red phosphorescence with non‐toxic elements remains a challenge and, thus, our new class of soluble (processable) polymeric phosphor is of great interest. Furthermore, the formation of bismuth‐rich cores within organic–inorganic block copolymer spherical micelles is possible, leading to patterned arrays of bismuth in the film state.

Highly Fluorescent Benzophosphole Oxide Block-Copolymer Micelles

“…The requisite zirconacycle precursor 1 was first formed via a cyclization of bis(parabiphenyl) acetylene bpCCbp and Cp 2 ZrPh 2 , as shown in Scheme 1 (see Figure S2 for the X-ray structure of 1). 25 Following the Fagan−Nugent 26,27 protocol previously used in the Rivard group for the generation of tellurium-28−33 and bismuth-containing 20,21 heterocycles, compound 1 was reacted with 1 equiv of PCl 3 to generate the chlorophosphole 2 in a quantitative yield (Scheme 1). As the Cp 2 ZrCl 2 byproduct from metallacycle transfer could not easily be separated from 2, the product mixture of 2/Cp 2 ZrCl 2 was used as is for further derivatization chemistry (vide infra).…”

“…Our group recently reported an efficient synthetic strategy for the incorporation of red phosphorescent benzobismole units into block copolymers via ring-opening metathesis polymerization (ROMP) with the Grubbs third-generation catalyst. 20,21 The resulting block copolymers undergo selfassembly in hexanes/tetrahydrofuran (THF) to yield emissive spherical micelles. 20 In this study, we incorporate the highly AIE-active benzophosphole molecular class V (Chart 1) in homo-and block copolymers to attain efficient bright bluegreen fluorescence, both in solution and in the solid state.…”

“…20,21 The resulting block copolymers undergo selfassembly in hexanes/tetrahydrofuran (THF) to yield emissive spherical micelles. 20 In this study, we incorporate the highly AIE-active benzophosphole molecular class V (Chart 1) in homo-and block copolymers to attain efficient bright bluegreen fluorescence, both in solution and in the solid state. We also introduce a precipitation-based fluoride ion detection method whereby substoichiometric quantities of F − can interact with a pinacolboronate (BPin)-rich corona in a spherical micelle, leading to rapid polymer precipitation; visualization of this process is facilitated by the retention of bright emission of the solid polymer precipitate.…”

Controlling Molecular Aggregation-Induced Emission by Controlled Polymerization

“…In addition, ROMP is another type of controlled polymerization based on olefin metathesis [ 35 ]. It has also demonstrated great ability in the synthesis of well-defined fluorescent polymers [ 49 ], including AIE polymers [ 100 , 101 , 102 , 103 , 104 ] and ladderphanes [ 105 ]. Although ROMP-based single-fluorophore AIE polymers have not been reported so far, end-group functionalization may provide an approximate method for this [ 106 , 107 ] if the incorporation of AIE fluorophores can be precisely controlled with high conversion rates.…”

Polymorphic Pure Organic Luminogens with Through‐Space Conjugation and Persistent Room‐Temperature Phosphorescence

“…Recently, pure organic luminogens with room‐temperature phosphorescence (RTP) have attracted increasing attention owing to their fundamental importance in deciphering the photophysical processes of singlet and triplet excitons, as well as their potential applications in sensing, bioimaging, anticounterfeiting, and so forth. In particular, those with persistent RTP ( p ‐RTP) are also promising owing to the retaining of RTP emission even after ceasing the excitation sources, which means they can be used in encryption, oxygen and chemical sensing, and high‐resolution molecular imaging with ideal signal‐to‐noise ratios .…”