Padmanaban, G and Ramakrishnan, S (2001) An improved method for the control of conjugation length in MEHPPV via a xanthate precursor route. In: Synthetic Metals, 119 (1-3). pp. 533-534.
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Precursors of MEHPPV, that contain two types of thermally eliminatable groups, viz., xanthate and methoxy groups, were prepared readily starting from the Wessling polyelectroiyte precursor. The high nucleophilicity of potassium ethyl xanthate, when compared to previously reported sodium acetate, resulted in improved control over the composition, and it also simplified the synthetic procedure. It was seen that the extent of xanthate incorporation is limited by the xanthate availability, and substitution by methanol occurred almost exclusively only after all xanthate had been consumed - suggesting an almost sequential substitution. The thermal elimination of the xanthates, as expected, also occurred more easily - at temperatures as low as 180 °C, in xylene solutions. The selective nature of the elimination was confirmed by $^1 H$ NMR spectroscopy. The absorption and emission spectra of the resulting partially conjugated MEHPPV via this xanthate route exactly paralleled those via the acetate route, exhibiting the expected red-shift with increasing elimination.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Elsevier.|
|Keywords:||MEHPPV;Conjugation length;Photoluminescence (PL)|
|Department/Centre:||Division of Chemical Sciences > Inorganic & Physical Chemistry|
|Date Deposited:||13 Mar 2007|
|Last Modified:||19 Sep 2010 04:36|
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