Hückel Theory + Reorganization Energy = Marcus–Hush Theory: Breakdown of the 1/n Trend in π-Conjugated Poly-p-phenylene Cation Radicals Is Explained
| Autor: | Marat R. Talipov, Maxim V. Ivanov, Anitha Boddeda, Sameh H. Abdelwahed, Rajendra Rathore |
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| Rok vydání: | 2017 |
| Předmět: |
Radical
02 engineering and technology Conjugated system Fluorene Hückel method 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Redox 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry.chemical_compound General Energy chemistry Computational chemistry Poly(p-phenylene) Physical chemistry Molecular orbital Physical and Theoretical Chemistry Absorption (chemistry) 0210 nano-technology |
| Zdroj: | The Journal of Physical Chemistry C. 121:1552-1561 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.6b12111 |
| Popis: | Among the π-conjugated poly-p-phenylene wires, fluorene-based poly-p-phenylene (FPPn) wires have been extensively explored for their potential as charge-transfer materials in functional photovoltaic devices. Herein, we undertake a systematic study of the redox and optical properties of a set of FPPn (n = 2–16) wires. We find that, while their absorption maxima (νabs) follow a linear trend against cos[π/(n + 1)] up to the polymeric limit, redox potentials (Eox) show an abrupt breakdown from linearity beginning at n ∼ 8. These observations prompted the development of a generalized model to describe the unusual evolution of redox and optical properties of poly-p-phenylene wires. We show that the cos[π/(n + 1)], commonly expressed as 1/n, dependence of the properties of various π-conjugated wires has its origin in Huckel molecular orbital (HMO) theory, which however, fails to predict the evolution of the redox potentials of these wires, as the oxidation-induced structural/solvent reorganization is unaccounted... |
| Databáze: | OpenAIRE |
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