The influence of substituents of perylenediimides on their spectroscopic properties

Bukauskytė, Austėja; Karpicz, Renata; Striela, Romualdas; Labanauskas, Linas; Gruodis, Alytis; Peckus, Domantas; Augulis, Ramu̅nas; Gulbinas, Vidmantas

doi:10.1016/j.jlumin.2017.11.023

Cited by 5 publications

(6 citation statements)

References 40 publications

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“…Φ f for PDI-Ph is 0.61 and 0.43 in toluene and CH 2 Cl 2 , respectively, and is significantly quenched compared to that of PDI-C11 (Φ f = 0.99 in CH 2 Cl 2 ) . The unhindered motion of the phenyl group at the headland position acts as a “loose bolt”, which accelerates S 1 → S 0 internal conversion by coupling nuclear motion to the excited electronic state to kinetically outcompete fluorescence and thus reduce Φ f . Similarly, Φ f for p- PDI 2 and m- PDI 2 in toluene are 0.52 and 0.39, respectively, while in CH 2 Cl 2 these values decrease to 0.27 and 0.25, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…46 The unhindered motion of the phenyl group at the headland position acts as a "loose bolt", which accelerates S 1 → S 0 internal conversion by coupling nuclear motion to the excited electronic state to kinetically outcompete fluorescence and thus reduce Φ f . 47 Similarly, Φ f for p-PDI 2 and m-PDI 2 in toluene are 0.52 and 0.39, respectively, while in CH 2 Cl 2 these values decrease to 0.27 and 0.25, respectively. Indeed, lower Φ f values are expected in a high-polarity solvent due to stabilization of a charge-transfer (CT) contribution to the electronic structure that opens another nonradiative decay pathway, as discussed below, although other solvent effects may also be contributing.…”

Section: ■ Introductionmentioning

confidence: 99%

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Symmetry-Breaking Charge Separation in Phenylene-Bridged Perylenediimide Dimers

et al. 2021

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Perylenediimides (PDIs) are important molecular building blocks that are being investigated for their applicability in optoelectronic technologies. Covalently linking multiple PDI acceptors at the 2,5,8,11 (headland) positions adjacent to the PDI carbonyl groups is reported to yield higher power conversion efficiencies in photovoltaic cells relative to PDI acceptors linked at the 1,6,7,12 (bay) positions. While the photophysical properties of PDIs linked via the bay positions have been investigated extensively, those linked at the headland positions have received far less attention. We showed previously that symmetry-breaking charge separation (SB-CS) in PDIs hold promise as a strategy for increasing photovoltaic efficiency. Here we use transient absorption and emission spectroscopies to investigate the competition between SB-CS, fluorescence, and internal conversion in three related PDI dimers linked at the headland positions with o-, m-, and p-phenylene moieties: o-PDI 2 , m-PDI 2 , and p-PDI 2 , respectively. It is found that o-PDI 2 supports SB-CS yielding PDI •+ −PDI •− , which is in equilibrium with the o-PDI 2 first excited state in a polar solvent (CH 2 Cl 2 ) while m-PDI 2 and p-PDI 2 exhibit accelerated internal conversion due to the motion of the linker along with subnanosecond intersystem crossing (ISC). Electronic coupling and structural dynamics are shown to play a significant role, with o-PDI 2 being the only member of the series that exhibits significant through-bond interchromophore coupling. The pronounced o-PDI 2 steric congestion prevents the free internal rotation that leads to rapid deactivation of the excited state in the other dimers.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Symmetry-Breaking Charge Separation in Phenylene-Bridged Perylenediimide Dimers

et al. 2021

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“…To investigate the potential energy transfer mechanism, first absolute photoluminescence quantum yield (Φ) measurements were carried out on pure ONC films, giving Φ of 12.5 ± 1.7, 5.2 ± 2.9, and 2.7 ± 1.2% for DMP-PDI, EP-PDI, and PDI-Br 2 ONCs, respectively. The lower Φ found in the latter two ONCs may have to do with formation of excimers and triplet states for EP-PDI owing to face-to-face aggregation and singlet–triplet transition through intersystem crossing owing to the double Br substitution in PDI-Br 2 . Thereafter, single-particle time-resolved fluorescence (TRF) measurements were conducted (see the Supporting Information for details).…”

Section: Results and Discussionmentioning

confidence: 95%

A Nanoscopic View of Photoinduced Charge Transfer in Organic Nanocrystalline Heterojunctions

et al. 2019

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Organic photovoltaics enable cost-efficient, tunable, and flexible platforms for solar energy conversion, yet their performance and stability are still far from optimal. Here, we present a study of photoinduced charge transfer processes between electron donor and acceptor organic nanocrystals as part of a pathfinding effort to develop robust and efficient organic nanocrystalline materials for photovoltaic applications. For this purpose, we utilized nanocrystals of perylenediimides as the electron acceptors and nanocrystalline copper phthalocyanine as the electron donor. Three different configurations of donor–acceptor heterojunctions were prepared. Charge transfer in the heterojunctions was studied with Kelvin probe force microscopy under laser or white light excitation. Moreover, detailed morphology characterizations and time-resolved photoluminescence measurements were conducted to understand the differences in the photovoltaic processes of these organic nanocrystals. Our work demonstrates that excitonic properties can be tuned by controlling the crystal and interface structures in the nanocrystalline heterojunctions, leading to a minimization of photovoltaic losses.

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“…51 In addition, the extended conjugation in the bay position also plays a role in reducing the quantum yield. 37 The observation of TDI dominant emission (Figure 2) when the PDI is selectively excited suggests that intramolecular ET or EET exists in TP and TBP, due to the large overlap between the emission of PDI and the absorption of TDI as shown in Figure S14. Under 600 nm selective excitation of TDI units (Figure S17), the PL spectra are almost the same as that of 490 nm excitation, which suggests performance of the nonradiative process from PDI to TDI when the PDI unit is excited.…”

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confidence: 97%

“…The maximum absorption peak of TP is also red-shifted (∼22 nm) in comparison to TDI monomer due to extended conjugation in the bay position. Previous studies have shown that extended conjugation into the phenyl substituent at the bay position would cause broadening and shift of the absorption. − We have synthesized a bay-phenyl substituted TDI compound TDI-Ph (Figure S15). The absorption spectrum of TDI-Ph is red-shifted (∼11 nm) in comparison to TDI monomer and PL quantum yield is reduced to 0.45.…”

mentioning

confidence: 99%

Efficient Energy Transfer in a Rylene Imide-Based Heterodimer: The Role of Intramolecular Electronic Coupling

Peng

Shao

Wang

et al. 2023

J. Phys. Chem. Lett.

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The development of antenna molecules with simplified structures can effectively avoid the complex exciton dynamics resulting from conformational mobility. Two distinct heterodimers TP and TBP comprising a perylenediimide (PDI) donor and terrylenediimide (TDI) acting as an energy sink were investigated. Tuned by varying functionalization positions, the bayto-bay-linked TP offers a strong chromophore coupling, while the bay-to-N-linked TBP exhibits a weak chromophore coupling. Using transient absorption spectroscopy, we found that TP underwent ultrafast vibrational relaxation (τ VR < 400 fs) from upper vibrational energy levels of the singlet states after pumping at 490 nm, and followed by electron transfer (ET, τ ET = 2.5 ps) from TDI to PDI. TBP exhibited ultrafast excitation energy transfer (EET, τ EET = 0.48 ± 0.1 ps) from the excited PDI donor to TDI acceptor, and the subsequent charge transfer (CT) process was almost quenched. This result provides insight into designing novel small molecules capable of efficient energy transfer.

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The influence of substituents of perylenediimides on their spectroscopic properties

Cited by 5 publications

References 40 publications

Symmetry-Breaking Charge Separation in Phenylene-Bridged Perylenediimide Dimers

Symmetry-Breaking Charge Separation in Phenylene-Bridged Perylenediimide Dimers

A Nanoscopic View of Photoinduced Charge Transfer in Organic Nanocrystalline Heterojunctions

Efficient Energy Transfer in a Rylene Imide-Based Heterodimer: The Role of Intramolecular Electronic Coupling

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