Peculiar Photoinduced Electron Transfer in Porphyrin–Fullerene Akamptisomers

Abstract

Porphyrin–fullerene dyads are promising candidates for organic photovoltaic devices. The electron‐transfer (ET) properties of the molecular devices depend significantly on the mutual position of the donor and acceptor. Recently, a new type of molecular isomerism (akamptisomerism) has been discovered. In the present study, we explore how photoinduced ET can be modulated by passing from one akamptisomer to another. To this aim, four akamptisomers of the quinoxalinoporphyrin–[60]fullerene complex are selected for computational study. The most striking finding is that, depending on the isomer, the porphyrin unit in the dyad can act as either electron donor or electron acceptor. Thus, the stereoisomeric diversity allows one to change the direction of ET between the porphyrin and fullerene moieties. To understand the effect of akamptisomerism on the photoinduced ET processes, a detailed analysis of initial and final states involved in the ET is performed. The computed rate for charge separation is estimated to be in the region of 1–10 ns−1. The formation of a long‐living quinoxalinoporphyrin anion radical species is predicted.

Photoinduced electron transfer and unusual environmental effects in fullerene–Zn-porphyrin–BODIPY triads

“…17,18 Among the acceptor units utilized for preparation of photosynthetic systems, fullerenes demonstrate such important properties as low reduction potentials, very strong electron acceptor properties and small reorganization energies. [19][20][21][22][23][24][25][26][27] In the last decade, they have got noticeable popularity in chemical and material sciences due to development of their functionalization methods that allowed to overcome solubility issues as well as tune electronic and photophysical properties. 28,29 The electronic communication between donor and acceptor is a key feature in the design of photosystems.…”

Triquinoline‐ versus Fullerene‐Based Cycloparaphenylene Ionic Complexes: Comparison of Photoinduced Charge‐Shift Reactions

“…To estimate the effect of polar environment on electronic excitations, a well‐proven COSMO‐like model with dichloromethane (DCM) as the solvent was applied. The GS solvation energies are calculated to be −1.76, −1.95, and −2.09 eV for TQ⋅H + ‐COR, TQ⋅H + ⊂[12]CPP and (TQ⋅H + ‐COR)⊂[12]CPP, respectively.…”

“…To estimate the effect of polar environment on electronic excitations, aw ell-proven COSMO-like model [29][30][31][32] with dichloromethane (DCM)a st he solventw as applied. The GS solvation energies are calculated to be À1.76, À1.95, and À2.09 eV for TQ•H + -COR, TQ•H + & [12]CPP and (TQ•H + -COR)& [12]CPP,r espectively.Since the complexes carry apositive charge, they interact strongly with the polar medium.…”

Ultrastrong Regulation Effect of Electric Field on Cyclo[18]carbon: Phenomenon and Essence

“…Due to the quite unusual geometric and electronic structures of the cyclo [18]carbon, this new member of carbon allotrope family has received great attentions since its first experimental observation in condensed phase in 2019. [1][2][3] Significant theoretical efforts have been devoted to explore its characteristics and potential applications, [4][5][6][7][8][9][10] and recently we have comprehensively investigated its properties from different aspects, including bonding nature, aromaticity, electronic and vibrational spectra, non-linear optical property, intermolecular interaction, dynamic behavior and so on. [11][12][13][14] It is well known that external electric field (EEF) often has a great influence on chemical systems, and this has always been a hot research field.…”