Orientational Dependence of Cofacial Porphyrin-Quinone Electronic Interactions within the Strong Coupling Regime
| Autor: | Youn K. Kang, Peng Zhang, Igor V. Rubtsov, Michael J. Therien, George Bullard, Jieru Zheng, David N. Beratan |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Porphyrins
Time Factors 010304 chemical physics Diastereomer chemistry.chemical_element Electrons Zinc 010402 general chemistry 01 natural sciences Porphyrin Article 0104 chemical sciences Surfaces Coatings and Films Quinone Coupling (electronics) chemistry.chemical_compound Crystallography chemistry 0103 physical sciences Materials Chemistry Strong coupling Benzoquinones Physical and Theoretical Chemistry Density Functional Theory |
| Zdroj: | J Phys Chem B |
| Popis: | We examine the relative magnitudes of electronic coupling H(DA) in two face-to-face rigid and diastereomeric (porphinato)zinc(II)-quinone (PZn-Q) assemblies, 1β-ZnA, and 1β-ZnB, in which the six quinonyl carbon atoms lie in virtually identical arrangements relative to the PZn plane at sub-van der Waals donor-acceptor (D-A) interplanar separations. Steady-state and time-resolved transient optical data and computational studies show that minor differences in relative D-A cofacial orientation give rise to disparate H(DA) magnitudes for both photoinduced charge separation (CS) and thermal charge recombination (CR). Time-dependent density functional theory (TDDFT) computations illuminate the nature of direct charge transfer states, and the electronic structural factors that give rise to these differential H(DA)s. These data show more extensive mixing of locally excited (LE) and CS states in 1β-ZnA relative to 1β-ZnB, and that these H(DA) differences track the magnitudes of electronic coupling matrix elements determined from steady-state electronic spectral data and thermal CR rate constants measured via pump-probe spectroscopy. Collectively, this work shows that electron transfer dynamics may be manipulated in cofacial D-A systems, even at sub-van der Waals contact, provided that conformational rigidity precludes structural fluctuations that modulate D-A interactions on the charge transfer time scale. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|