Chen C.-HLai G.-QTIEN-YAU LUH2021-08-032021-08-032021249297https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101579518&doi=10.1021%2facs.macromol.0c02362&partnerID=40&md5=45e79b0c112fe865e1e4fdcda5f3e8b0https://scholars.lib.ntu.edu.tw/handle/123456789/575877Tetraarylethene (TAE) has been used as linkers in polynorbornene- and polycyclobutene-based double-stranded ladderphanes and as pendants in related single-stranded polymers. The adjacent TAE linkers in these polymers are separated by 4.5-5.5 ?. Upon irradiation at 315 nm in dichloromethane (DCM), TAE excimer emission is observed at 493 nm with quantum yield φ = 0.005-0.015. When MeOH/DCM (3/1) is used as the medium, φs of hexyloxy-substituted TAE ladderphanes increase to 0.45-0.48 due to aggregation-enhanced excimer emission (AEEE). TAE-appended single-stranded polynorbornene has φ = 0.21 under the same conditions. The neighboring TAE chromophores in these single-stranded polymers may not be eclipsed and therefore might be less favored for excimer formation. Entangling of hexyloxy groups, inter alia, may be responsible for AEEE. Replacement of a hexyloxy group by a methoxy group leads to a reduction in the quantum yield by 70% due to lack of entangling. The overall process that is responsible for AEEE involves excimer formation, aggregation of polymers, plus entangling of long-chain alkyl groups. ? 2021 American Chemical Society. All rights reserved.Chromophores; Dichloromethane; Light emission; Quantum yield; Alkyl groups; Excimer emissions; Excimer formation; Long chains; Methoxy group; Overall process; Polynorbornenes; Polymers[SDGs]SDG3journal article10.1021/acs.macromol.0c023622-s2.0-85101579518