Synthesis and Fluorescence Characterization of MEHPPV Oligomers

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• 作者：Andrew J. Tilley ; Stephen M. Danczak ; Christine Browne ; Timothy Young ; Tina Tan ; Kenneth P. Ghiggino ; Trevor A. Smith ; Jonathan White
• 刊名：Journal of Organic Chemistry
• 出版年：2011
• 出版时间：May 6, 2011
• 年：2011
• 卷：76
• 期：9
• 页码：3372-3380
• 全文大小：910K
• 年卷期：v.76,no.9(May 6, 2011)
• ISSN：1520-6904

文摘

Trimer, tetramer, and pentamer oligomers based on the polymer backbone structure of poly[2-methoxy-5-(2鈥?ethylhexyloxy)-1,4-phenylenevinylene] (MEHPPV) have been synthesized by Horner鈭扺adsworth鈭扙mmons reactions. The fluorescence spectra, emission quantum yields, and lifetimes of the oligomers have been characterized in dilute chloroform solutions. The oligomers exhibit a sequential increase in absorption and emission wavelength maxima and a decrease in fluorescence lifetime as the 蟺 conjugation length is increased. The shortening in excited state lifetime is shown to be due to an increase in the rates of both radiative and nonradiative processes. The absence of a mirror-image relationship for the absorption and fluorescence spectra of the oligomers is attributed to the photoexcitation of a range of torsional configurations followed by relaxation to a more planar arrangement that then emits.