Fluorescence quenching of a poly(para-phenylene ethynylenes) by C60 fullerenes
Fluorescence quenching of a poly(para-phenylene ethynylenes) by C60 fullerenes
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DOI：
10.1016/j.jphotochem.2012.08.015
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发表时间：
2012-12-01
影响因子：
4.3
通讯作者：
Bucknall, David G.
中科院分区：
文献类型：
--
作者：
Campbell, Katie;Zappas, Andrew;Bucknall, David G.
用C-60对聚苯乙烯（PPE）进行荧光猝灭，研究了富勒烯与聚苯乙烯（PPE）的配合物形成。详细研究了侧链化学，特别是给电子能力和分子量对配合物强度的影响。荧光猝灭测量表明，络合物形成的数量级为10(3)-10(4)dm(3)/mol，比先前研究的c -60小有机分子络合物大6个数量级，比c -60环聚合物体系大一个数量级。具有不同侧链化学性质的PPE的配合物强度无显著差异，表明C-60相互作用主要发生在共轭PPE主链上。在研究的较低PPE分子量下，复合物形成的结合常数保持不变；然而，在研究的最高分子量下观察到增加。我们将这种增加归因于C-60分子一次淬灭多个PPE单位，从而在更高分子量和更大的结合常数下增强淬灭。基于相互作用的强度和侧基对相互作用的贡献，我们得出结论，C-60笼和PPE骨干之间的pi-pi相互作用是观察到的相对较强的相互作用的原因。(C) 2012 Elsevier B.V.版权所有
Complex formation between fullerenes and poly(para-phenylene ethynylene) (PPE) is studied through fluorescence quenching of PPE by C-60. The influence of side chain chemistry, particularly with respect to electron donating capability, and molecular weight on the complex strength is examined in detail. Fluorescence quenching measurements indicate complex formation on the order of 10(3)-10(4) dm(3)/mol, six orders of magnitude larger than previously studied C-60-small organic molecule complexes and an order of magnitude larger than C-60-cyclic polymer systems. No significant difference in complex strength was observed among PPEs with different side chain chemistry, indicating that C-60 interaction occurs largely with the conjugated PPE backbone. At the lower PPE molecular weights investigated, the association constant for complex formation remains constant: however, an increase is observed at the highest molecular weight studied. We attribute this increase to the C-60 molecule quenching more than one PPE unit at once, resulting in enhanced quenching at higher molecular weights and larger association constant. Based on the strength of interaction and lack of side group contribution to the interaction, we conclude that pi-pi interactions between the C-60 cage and PPE backbone are responsible for the comparatively strong interactions observed. (C) 2012 Elsevier B.V. All rights reserved.