Molecular Design Principle for Efficient Singlet Fission Based on Diradical Characters and Exchange Integrals: Multiple Heteroatom Substitution Effect on Anthracenes

2020 ◽  
Vol 124 (22) ◽  
pp. 11800-11809 ◽  
Author(s):  
Takanori Nagami ◽  
Kenji Okada ◽  
Hajime Miyamoto ◽  
Wataru Yoshida ◽  
Takayoshi Tonami ◽  
...  
Keyword(s):  
Design Principle ◽  
Molecular Design ◽  
Substitution Effect ◽  
Singlet Fission ◽  
Heteroatom Substitution

scholarly journals Molecular design strategy for practical singlet fission materials: The charm of donor/acceptor decorated quinoidal structure

CCS Chemistry ◽  
2021 ◽  
pp. 1-17
Author(s):  
Long Wang ◽  
Xiaomei Shi ◽  
Shishi Feng ◽  
WanZhen Liang ◽  
Hongbing Fu ◽  
...  
Keyword(s):  
Molecular Design ◽  
Design Strategy ◽  
Singlet Fission ◽  
Donor Acceptor

Singlet Fission: Mechanisms and Molecular Design

2021 ◽  
pp. 291-311
Author(s):  
Victor Gray ◽  
Leah Weiss ◽  
Akshay Rao
Keyword(s):  
Molecular Design ◽  
Singlet Fission

Aza-substitution effect on the Q-band excitations of free-base porphin, chlorin, and bacteriochlorin: SAC-CI theoretical study

2005 ◽  
Vol 09 (05) ◽  
pp. 305-315 ◽  
Author(s):  
Jun-ya Hasegawa ◽  
Takayuki Kimura ◽  
Hiroshi Nakatsuji
Keyword(s):  
Dipole Moment ◽  
Excited States ◽  
Molecular Design ◽  
Decomposition Analysis ◽  
Substitution Effect ◽  
Transition Dipole Moment ◽  
Orbital Energy ◽  
Free Base ◽  
Transition Dipole ◽  
Near Degeneracy

Electronic structure of the excited states and absorption spectra of free-base azaporphins, azachlorin, and azabacteriochlorin were systematically investigated by SAC-CI calculations. Aza-substitution at the meso position affects the orbital energy of the next-HOMO, and the transition dipole moment enlarges as the number of the substitution increases. Some of the aza-substitutions dramatically affect the direction of the transition dipole, due to reduction of the molecular symmetry, which was studied in detail by a decomposition analysis of the transition dipole moment. Tetraza-substitution in chlorin and bacteriochlorin increases the oscillator strength more than that of tetrazaporphin. The mechanism underlying these changes originates mainly from the relaxation of near-degeneracy in the main configurations. These findings would be useful for the application to the molecular design of the excited states.

scholarly journals Designing Singlet Fission Candidates from Donor-Acceptor Copolymers

2020 ◽  
Author(s):  
Jacob Terence Blaskovits ◽  
Maria Fumanal ◽  
Sergi Vela ◽  
Clemence Corminboeuf
Keyword(s):  
High Throughput Screening ◽  
Molecular Design ◽  
Crystal Packing ◽  
Cost Effective ◽  
Frontier Molecular Orbital ◽  
Structure Property ◽  
Singlet Fission ◽  
Structure Property Relationships ◽  
Large Databases ◽  
Donor Acceptor

<p>Singlet Fission (SF) has demonstrated significant promise for boosting the power conversion efficiency (PCE) of solar cells. Traditionally, SF is targeted as an intermolecular process, however its dependence on crystal packing makes molecular design difficult. In contrast, intramolecular SF (iSF) enables the exploration of tunable bi-chromophoric systems following well-defined structure-property relationships. In this work, we propose a set of parameters to screen conjugated donor-acceptor copolymer candidates with potential iSF behaviour. We focus our analysis on the E(S<sub>1</sub>)>2E(T<sub>1</sub>) thermodynamic condition and on the appropriate charge transfer (CT) character of S<sub>1</sub>. We map the CT character with respect to the frontier molecular orbital (FMO) energies of the constituent monomers, providing a cost-effective protocol for an accelerated screening of promising iSF donor-acceptor pairs, while minimizing the number of computations. These parameters are applied to a chemically diverse, curated library of 81 truncated dimers of synthetically feasible donor-acceptor copolymers. From our dataset, four candidates are flagged for iSF, two of which were previously experimentally reported. This protocol is envisioned to be scaled up for the high-throughput screening of large databases of donor-acceptor dimers for the design and identification of conjugated polymers capable of iSF. </p>

Ultra-fast intramolecular singlet fission to persistent multiexcitons by molecular design

2019 ◽  
Vol 11 (9) ◽  
pp. 821-828 ◽  
Author(s):  
Andrew B. Pun ◽  
Amir Asadpoordarvish ◽  
Elango Kumarasamy ◽  
Murad J. Y. Tayebjee ◽  
Daniel Niesner ◽  
...  
Keyword(s):  
Molecular Design ◽  
Singlet Fission

A molecular design principle towards luminescent polymorphic organic heterostructured architectures

2021 ◽  
Author(s):  
Qianqian Zhou ◽  
Yilong Lei ◽  
Hongbing Fu
Keyword(s):  
Design Principle ◽  
Molecular Design ◽  
Structural Relationship

A molecular design principle towards polymorphic organic heterostructures has been developed based on the well-matched structural relationship between two polymorphic components.

scholarly journals Identifying the Trade-off between Intramolecular Singlet Fission Requirements in Donor-Acceptor Copolymers

2020 ◽  
Author(s):  
Jacob Terence Blaskovits ◽  
Maria Fumanal ◽  
Sergi Vela ◽  
Raimon Fabregat ◽  
Clemence Corminboeuf
Keyword(s):  
Single Molecule ◽  
Molecular Design ◽  
Relative Energy ◽  
Frontier Molecular Orbital ◽  
Great Promise ◽  
Singlet Fission ◽  
Trade Off ◽  
Singlet Exciton ◽  
Donor Acceptor ◽  
Photoinduced Charge

Intramolecular singlet fission (iSF) has shown potential to improve the power conversion efficiency in photovoltaic devices by promoting the splitting of a photon-absorbing singlet exciton into two triplet excitons within a single molecule. Among different possibilities, the donor-acceptor modular strategy of copolymers has shown great promise in its ability to undergo iSF under certain conditions. However, the number of iSF donor-acceptor copolymers reported in the literature remains remarkably narrow and clear trends for the molecular design of better candidates have not yet been established. In this work, we identify the trade-off between the main iSF requirements of the donor-acceptor strategy and formulate design rules that allow them to be tuned simultaneously in a fragment-based approach. Based on a library of 2944 donor-acceptor copolymers, we establish simple guidelines to build promising novel materials for iSF. These consist in (1st) selecting an acceptor core with high intrinsic singlet-triplet splitting, (2nd) locating a donor with a larger monomer frontier molecular orbital (FMO) gap than that of the acceptor, and (3rd) tuning the relative energy of donor and/or acceptor FMOs through functionalization to promote photoinduced charge transfer in the resulting polymer. Remarkably, systems containing benzothiadiazole and thiophehe-1,1-dioxide acceptors, which have been shown to undergo iSF, fulfill all criteria simultaneously when paired with appropriate donors. This is due to their particular electronic features, which make them highly promising candidates in the quest for iSF materials.<br>

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