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Title: Tuning Singlet Fission in π-Bridge-π Chromophores

Journal Article · · Journal of the American Chemical Society
DOI:https://doi.org/10.1021/jacs.7b05204· OSTI ID:1413948
ORCiD logo [1]; ORCiD logo [1];  [2];  [3];  [4];  [5];  [1];  [1];  [1];  [1];  [6];  [1]; ORCiD logo [6];  [1];  [5];  [3]; ORCiD logo [7]; ORCiD logo [1]
  1. Columbia Univ., New York, NY (United States). Department of Chemistry
  2. University of New South Wales, Sydney (Australia). School of Photovoltaic and Renewable Energy Engineering; University of Cambridge (United Kingdom). Cavendish Laboratory
  3. University of New South Wales, Sydney (Australia). ARC Centre of Excellence in Exciton Science, School of Physics
  4. Cornell Univ., Ithaca, NY (United States). Department of Chemistry and Chemical Biology; Cambridge University (United Kingdom). Jesus College
  5. Cornell Univ., Ithaca, NY (United States). Department of Chemistry and Chemical Biology
  6. Princeton Univ., NJ (United States). Department of Chemistry
  7. Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials

For this study, we have designed a series of pentacene dimers separated by homoconjugated or nonconjugated bridges that exhibit fast and efficient intramolecular singlet exciton fission (iSF). These materials are distinctive among reported iSF compounds because they exist in the unexplored regime of close spatial proximity but weak electronic coupling between the singlet exciton and triplet pair states. Using transient absorption spectroscopy to investigate photophysics in these molecules, we find that homoconjugated dimers display desirable excited-state dynamics, with significantly reduced recombination rates as compared to conjugated dimers with similar singlet fission rates. In addition, unlike conjugated dimers, the time constants for singlet fission are relatively insensitive to the interplanar angle between chromophores, since rotation about σ bonds negligibly affects the orbital overlap within the π-bonding network. In the nonconjugated dimer, where the iSF occurs with a time constant >10 ns, comparable to the fluorescence lifetime, we used electron spin resonance spectroscopy to unequivocally establish the formation of triplet–triplet multiexcitons and uncoupled triplet excitons through singlet fission. Together, these studies enable us to articulate the role of the conjugation motif in iSF.

Research Organization:
Brookhaven National Laboratory (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC0012704; SC0015429
OSTI ID:
1413948
Report Number(s):
BNL-114743-2017-JA; KC0403020; TRN: US1800601
Journal Information:
Journal of the American Chemical Society, Vol. 139, Issue 36; ISSN 0002-7863
Publisher:
American Chemical Society (ACS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 120 works
Citation information provided by
Web of Science

References (49)

Recent Advances in Singlet Fission journal April 2013
Singlet Fission journal November 2010
Solar conversion efficiency of photovoltaic and photoelectrolysis cells with carrier multiplication absorbers journal October 2006
Thermodynamic Limit of Exciton Fission Solar Cell Efficiency journal September 2012
Semi-Empirical Limiting Efficiency of Singlet-Fission-Capable Polyacene/Inorganic Hybrid Solar Cells journal January 2014
Beyond Shockley–Queisser: Molecular Approaches to High-Efficiency Photovoltaics journal June 2015
Correlating Structure and Function in Organic Electronics: From Single Molecule Transport to Singlet Fission journal August 2015
Singlet fission in pentacene dimers journal April 2015
Intramolecular Singlet Fission in Oligoacene Heterodimers journal February 2016
Quantitative Intramolecular Singlet Fission in Bipentacenes journal July 2015
Tuneable Singlet Exciton Fission and Triplet-Triplet Annihilation in an Orthogonal Pentacene Dimer journal August 2015
Singlet Fission in a Covalently Linked Cofacial Alkynyltetracene Dimer journal January 2016
Long-Lived Triplet Excited States of Bent-Shaped Pentacene Dimers by Intramolecular Singlet Fission journal March 2016
Fast Singlet Exciton Decay in Push–Pull Molecules Containing Oxidized Thiophenes journal December 2014
A design strategy for intramolecular singlet fission mediated by charge-transfer states in donor–acceptor organic materials journal January 2015
High Yield Ultrafast Intramolecular Singlet Exciton Fission in a Quinoidal Bithiophene journal April 2015
Ultrafast Singlet Fission in a Push–Pull Low-Bandgap Polymer Film journal December 2015
Singlet Fission: Progress and Prospects in Solar Cells journal December 2016
Exploring Non-Condon Effects in a Covalent Tetracene Dimer: How Important Are Vibrations in Determining the Electronic Coupling for Singlet Fission? journal December 2014
Solution-Phase Singlet Fission in a Structurally Well-Defined Norbornyl-Bridged Tetracene Dimer journal June 2016
Tunable Electronic Coupling and Driving Force in Structurally Well-Defined Tetracene Dimers for Molecular Singlet Fission: A Computational Exploration Using Density Functional Theory journal September 2013
Synthesis of Geometrically Well-Defined Covalent Acene Dimers for Mechanistic Exploration of Singlet Fission journal April 2017
Unified model for singlet fission within a non-conjugated covalent pentacene dimer journal May 2017
A transferable model for singlet-fission kinetics journal May 2014
Singlet Fission via an Excimer-Like Intermediate in 3,6-Bis(thiophen-2-yl)diketopyrrolopyrrole Derivatives journal August 2016
Singlet Exciton Fission in Thin Films of tert -Butyl-Substituted Terrylenes journal April 2015
Two Thin Film Polymorphs of the Singlet Fission Compound 1,3-Diphenylisobenzofuran journal May 2014
Different Rates of Singlet Fission in Monoclinic versus Orthorhombic Crystal Forms of Diphenylhexatriene journal November 2013
Molecular Packing Determines Singlet Exciton Fission in Organic Semiconductors journal June 2014
Maximizing Singlet Fission by Intermolecular Packing journal September 2014
Aqueous Colloidal Acene Nanoparticles: A New Platform for Studying Singlet Fission journal July 2013
Efficient Singlet Fission Discovered in a Disordered Acene Film journal March 2012
Tuning the role of charge-transfer states in intramolecular singlet exciton fission through side-group engineering journal December 2016
A Covalently Linked Tetracene Trimer: Synthesis and Singlet Exciton Fission Property journal January 2017
A Direct Mechanism of Ultrafast Intramolecular Singlet Fission in Pentacene Dimers journal May 2016
Tuning Conductance in π–σ–π Single-Molecule Wires journal June 2016
Electronic Absorption Spectra of Neutral Pentacene (C 22 H 14 ) and Its Positive and Negative Ions in Ne, Ar, and Kr Matrices journal August 2000
Microscopic theory of singlet exciton fission. II. Application to pentacene dimers and the role of superexchange journal March 2013
Quintet multiexciton dynamics in singlet fission journal October 2016
Exciton Correlations in Intramolecular Singlet Fission journal June 2016
Singlet Fission in Polypentacene journal September 2016
Direct Observation of a Charge-Transfer State Preceding High-Yield Singlet Fission in Terrylenediimide Thin Films journal December 2016
Distinct properties of the triplet pair state from singlet fission journal July 2017
Properties of Poly- and Oligopentacenes Synthesized from Modular Building Blocks journal February 2016
Localization length scales of triplet excitons in singlet fission materials journal September 2015
An EPR study of the triplet state of pentacene by electron spin-echo techniques and laser flash excitation journal March 1980
Comments on exciton fission and electron spin resonance in tetracene single crystals journal October 1972
Strongly exchange-coupled triplet pairs in an organic semiconductor journal October 2016
Singlet exciton fission in solution journal November 2013

Cited By (34)

High‐Yield Generation of Triplet Excited States by an Efficient Sequential Photoinduced Process from Energy Transfer to Singlet Fission in Pentacene‐Modified CdSe/ZnS Quantum Dots journal July 2018
Azaarene Dimers journal March 2019
Singlet exciton fission in a linear tetracene tetramer journal January 2018
Substituent effects on energetics and crystal morphology modulate singlet fission in 9,10-bis(phenylethynyl)anthracenes journal July 2019
Searching for Diradicaloid Chromophores with Efficient Singlet Fission: Cyano‐Group Substitution of Difuropyrene Systems journal May 2019
Singlet fission in a hexacene dimer: energetics dictate dynamics journal January 2020
Intramolecular singlet fission in a face-to-face stacked tetracene trimer journal January 2018
Feinabstimmung von intramolekularem resonantem Förster-Energietransfer und Aktivierung intramolekularer Singulettspaltung journal October 2018
Conformational Planarization versus Singlet Fission: Distinct Excited-State Dynamics of Cyclooctatetraene-Fused Acene Dimers journal March 2018
Identifying triplet pathways in dilute pentacene films journal October 2018
Morphology independent triplet formation in pentalene films: Singlet fission as the triplet formation mechanism journal September 2019
Pentacene Dimers as a Critical Tool for the Investigation of Intramolecular Singlet Fission journal March 2018
Tuning Intramolecular Förster Resonance Energy Transfer and Activating Intramolecular Singlet Fission journal October 2018
Crystalline silicon solar cells with tetracene interlayers: the path to silicon-singlet fission heterojunction devices journal January 2018
Using sulfur bridge oxidation to control electronic coupling and photochemistry in covalent anthracene dimers journal January 2019
Lessons from intramolecular singlet fission with covalently bound chromophores journal January 2020
Fluctuating exchange interactions enable quintet multiexciton formation in singlet fission journal October 2019
Spin density encodes intramolecular singlet exciton fission in pentacene dimers journal January 2019
Liquid Crystallinity as a Self‐Assembly Motif for High‐Efficiency, Solution‐Processed, Solid‐State Singlet Fission Materials journal July 2019
Conformational Planarization versus Singlet Fission: Distinct Excited-State Dynamics of Cyclooctatetraene-Fused Acene Dimers journal March 2018
Heavy-atom effects on intramolecular singlet fission in a conjugated polymer journal July 2019
A molecular movie of ultrafast singlet fission journal September 2019
Impact of non-equilibrium molecular packings on singlet fission in microcrystals observed using 2D white-light microscopy journal December 2019
Singlet fission in spiroconjugated dimers journal May 2019
Azaacene Dimers: Acceptor Materials with a Twist journal November 2019
Quantum dynamical simulation of intramolecular singlet fission in covalently coupled pentacene dimers journal July 2019
Weakly coupled triplet pair states probed by quantum beating in delayed fluorescence in tetracene crystals journal October 2019
Ultra-fast intramolecular singlet fission to persistent multiexcitons by molecular design journal August 2019
Davydov splitting and singlet fission in excitonically coupled pentacene dimers journal January 2019
Low magnetic field effects on triplet pair annihilations at canonical orientations journal December 2019
A molecular movie of ultrafast singlet fission text January 2019
Identifying triplet pathways in dilute pentacene films collection January 2018
A molecular movie of ultrafast singlet fission. text January 2019
Davydov splitting and singlet fission in excitonically coupled pentacene dimers null January 2019


Figures / Tables (6)