Conjugated hyperbranched poly(aryleneethynylene)s: synthesis, photophysical properties, superquenching by explosive, photopatternability, and tunable high refractive indices.
Triphenylamine (TPA)-based conjugated hyperbranched poly(aryleneethynylene)s (PAEs), hb-P1/2, hb-P1/3, and hb-P1/4, were synthesized with high molecular weights and good solubilities through Sonogashira coupling reactions. These PAEs exhibited outstanding thermal stabilities and different emission behaviors. Tetraphenylethene (TPE)-containing hb-P1/2 fluoresced faintly in THF, although its light emission was enhanced by aggregate formation in aqueous media or in thin films, thereby exhibiting an aggregation-induced emission-enhancement (AIEE) effect. Whereas 1,1,2,3,4,5-hexaphenylsilole (HPS)-bearing hb-P1/3 showed no significant change in emission intensity with increasing water content in aqueous media, hb-P1/4, which consisted of TPA-fluorenone donor-acceptor groups, presented almost identical absorptions, but both positive and negative solvatochromic emissions in various solvents. A superquenching effect was observed in the picric-acid-detection process by using nanosuspensions of hb-P1/2. All of the polymers possessed good film formability. UV irradiation of the thin films induced simultaneous photobleaching and cross-linking, thus making them applicable in the fabrication of 2D and 3D patterns. Furthermore, the polymer films also showed high refractive indices, which were tunable upon exposure to UV light.
Department of Chemistry, Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China.
Wang Zhang
WZ
Yuan
Rongrong
R
Hu
Jacky W Y
JW
Lam
Ni
N
Xie
Cathy K W
CK
Jim
Ben Zhong
BZ
Tang
D000480:Alkynes / Q000138:chemical synthesis* / Q000737:chemistry; D049449:Luminescence; D015394:Molecular Structure; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D012031:Refractometry; D013055:Spectrophotometry, Infrared; D014466:Ultraviolet Rays
D000480:Alkynes; D011108:Polymers