Conjugated Copolymers of Poly(arylenevinylene)s: Synthesis by Ring-Opening Metathesis Polymerization, Film Morphology, and Resonant Luminescence from Microspheres

Abstract

A series of copolymers of poly­(arylenevinylene)­s have been prepared by ring-opening metathesis polymerization (ROMP) of cyclic conjugated monomers composed of cyclopenta­dithiophene, bis­(thienyl)­benzo­thiadiazole, or bithiophene using a second-generation Grubbs catalyst and the sequential monomer addition technique. The spectroscopic, electrochemical, and morphological properties of these polymers are tailored by changing the chemical structures and fractions of the monomers. The polymers self-assemble to form microspheres (diameter: 2–5 μm), which act as whispering-gallery-mode optical resonators.

Molecular and Supramolecular Designs of Organic/Polymeric Micro-photoemitters for Advanced Optical and Laser Applications

“…To avoid these drawbacks, introduction of bulky side chains to twist the π-conjugated planes is an effective strategy for the formation of amorphous aggregates. We found that introduction of four methyl groups to the thiophene moieties in poly­[(9,9-dioctylfluorenyl-2,7-diyl)- alt -(bithiophene-2,5-diyl)] induces a highly twisted main chain with dihedral angles between the adjacent aromatic rings of 44–67°, which suppresses π–π stacking and leads to the formation of amorphous, well-defined microspheres. , To validate the generality of this strategy, self-assembly of more than 30 conjugated polymers was attempted. − The results show that π-conjugated polymers with high rigidity, planarity, and linearity hardly form spherical aggregates, while those with flexible or largely twisted main chains tend to form amorphous microspheres (Figure ). By spectroscopic monitoring of the self-assembly behavior of highly linear poly­[(9,9-dioctylfluorenyl-2,7-diyl)- alt -(5-octylthieno-[3,4- c ]­pyrrole-4,6-dione)] (F8TPD), a stepwise self-assembly was observed, the first step being the intrapolymer helical folding and the second step being the interpolymer aggregation to form microspheres …”

“…Transverse electric (TE) and magnetic (TM) modes are observed separately, which is characteristic for WGMs in a microsphere resonator. 30 The WGM PL is observed from various microspheres formed from isolated π-conjugated polymers, 22 polycarbazoles, 23 π-conjugated block copolymers, 24 and π-conjugated dendrimers. 25 Self-assembled microspheres composed of energy-donating and -accepting polymers display efficient intrasphere energy transfer (Figure 5b).…”

Cyclophanediene and Cyclophanetriene‐Based Conjugated Polymers

“…It should be noted that other larger donor and acceptor aryl-cyclophanes have been assembled and ring-opened to afford poly(arylene vinylene)s that are more commonly synthesized by ADMET (not a living polymerization) [34,35] but, similarly to the previously examined pCpt, these larger cyclophanes contain less ring strain and result in polymers with higher dispersities. [89][90][91][92][93] Additionally, these cyclophane monomers are out of the scope of this review as they do not contain an alkylphenylene or alkoxyphenylene unit.…”

Cyclic and linear dithienyl-anthryl vinylenes: synthesis, X-ray crystallography, spectroscopic properties, and photoinduced mechanical motions

“…[22][23][24][25][26][27] Recently, we have reported the synthesis and ROMP of various cyclophanedienes and cyclophanetrienes comprising bithiophene, cyclopentadithiophene, or benzothiadiazole. [28][29][30][31] These polymers obtained via ROMP formed microspheres to exhibit efficient whispering-gallery-mode photoluminescence (PL), showing potential application in microlasers. 29 Furthermore, cyclophanetriene with cyclophanediene and its polymers showed unique self-assembly and surface morphologies observed by scanning probe microscopy (STM) and atomic force microscopy (AFM).…”

“…[28][29][30][31] These polymers obtained via ROMP formed microspheres to exhibit efficient whispering-gallery-mode photoluminescence (PL), showing potential application in microlasers. 29 Furthermore, cyclophanetriene with cyclophanediene and its polymers showed unique self-assembly and surface morphologies observed by scanning probe microscopy (STM) and atomic force microscopy (AFM). 30 Although they have such unique features, there is sporadic research on multifunctional cyclophanedienes or cyclophanetrienes due to the difficult synthesis of cyclic conjugated molecules.…”