Specific Interactions in Complexes Formed by DNA and Conducting Polymer Building Blocks: Guanine and 3,4-(Ethylenedioxy)thiophene

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• 作者：Julien Preat ; Bruno Teixeira-Dias ; Catherine Michaux ; Eric A. Perp猫te ; Carlos Alem谩n
• 刊名：Journal of Physical Chemistry A
• 出版年：2011
• 出版时间：November 24, 2011
• 年：2011
• 卷：115
• 期：46
• 页码：13642-13648
• 全文大小：861K
• 年卷期：v.115,no.46(November 24, 2011)
• ISSN：1520-5215

文摘

In the present paper we report direct experimental evidence of the existence of hydrogen bonds between poly(3,4-(ethylenedioxy)thiophene) (PEDOT) and DNA complexes and bring deeper knowledge about how such interactions can take place in such species. To this end, we used both experimental and theoretical methodologies to examine the interactions between the building blocks composing these two macromolecules. The specific interaction natures between 3,4-(ethylenedioxy)thiophene (EDOT, E) and doubly protonated guanine (GH₂²⁺) monomers have been investigated using UV鈥搗is spectroscopy. Quantum mechanical calculations in the density functional theory (DFT) and time-dependent density functional theory (TDDFT) frameworks have been used to identify the structures of the possible complexes. These differ in the interaction pattern, and it was possible to interpret the absorption spectra in terms of intermolecular interactions. Our results allow verification of the previous hypothesis about the formation of specific N鈥揌路路路O interactions between G-containing nucleotide sequences and PEDOT. Clearly, DFT calculations indicate that E:GH₂²⁺ complexes are stabilized by N鈥揌路路路O interactions, which involve an E oxygen and the 鈭扤H and 鈭扤H₂ moieties of GH₂²⁺. Furthermore, TDDFT calculations are able to reproduce the absorption spectra (both energy gaps and relative oscillator strength magnitudes) of E and GH₂²⁺, as well as the complex.