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Dereka B, Maroli N, Poronik YM, Gryko DT, Kananenka AA. Excited-state symmetry breaking is an ultrasensitive tool for probing microscopic electric fields. Chem Sci 2024:d4sc04797d. [PMID: 39220161 PMCID: PMC11350400 DOI: 10.1039/d4sc04797d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Accepted: 08/21/2024] [Indexed: 09/04/2024] Open
Abstract
Microscopic electric fields are increasingly found to play a pivotal role in catalysis of enzymatic and chemical reactions. Currently, the vibrational Stark effect is the main experimental method used to measure them. Here, we demonstrate how excited-state symmetry breaking can serve as a much more sensitive tool to assess these fields. Using transient infrared spectroscopy on a quadrupolar probe equipped with nitrile groups we demonstrate both its superior sensitivity and that it does not suffer from the notorious hydrogen-bond induced upshift of the C[triple bond, length as m-dash]N stretch frequency. In combination with conventional ground-state infrared absorption, excited-state symmetry breaking can be used to disentangle even weak specific hydrogen bond interactions from general field effects. We showcase this capability with the example of weak C-H hydrogen bonds in polar aprotic solvents. Additionally, we reveal for the first time symmetry breaking driven not by solvent but by the entropy of the pendant side chains of the chromophore. Our findings not only enhance our understanding of symmetry-breaking charge-transfer phenomena but pave the way toward using them in electric field sensing modality.
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Affiliation(s)
- Bogdan Dereka
- Department of Chemistry, University of Zurich CH-8057 Zurich Switzerland
| | - Nikhil Maroli
- Department of Physics and Astronomy, University of Delaware Newark Delaware 19716 USA
| | - Yevgen M Poronik
- Institute of Organic Chemistry, Polish Academy of Sciences 01-224 Warsaw Poland
| | - Daniel T Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences 01-224 Warsaw Poland
| | - Alexei A Kananenka
- Department of Physics and Astronomy, University of Delaware Newark Delaware 19716 USA
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2
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Dereka B, Balanikas E, Rosspeintner A, Li Z, Liska R, Vauthey E. Excited-State Symmetry Breaking and Localization in a Noncentrosymmetric Electron Donor-Acceptor-Donor Molecule. J Phys Chem Lett 2024; 15:8280-8286. [PMID: 39143858 DOI: 10.1021/acs.jpclett.4c01694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2024]
Abstract
Electronic excitation in quadrupolar conjugated molecules rapidly localizes on a single electron donor-acceptor (DA) branch when in polar environments. The loss of center of inversion upon this excited-state symmetry breaking (ES-SB) can be monitored by exploiting the relaxation of the exclusion rules for IR and Raman vibrational transitions. Here, we compare ES-SB in a right-angled (1) and a centrosymmetric (2) DAD dyes using time-resolved IR spectroscopy. We show that the localization of the excitation can also be identified with the bent molecule 1. We find that contrary to dye 2, subpopulations with localized and delocalized excitation coexist for 1 in weak to medium polar solvents. This difference originates from the torsional disorder present in the excited state of 1 but not of 2. Additionally, irreversible localization in a bent molecule is shown to require higher solvent polarity than in a centrosymmetric one.
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Affiliation(s)
- Bogdan Dereka
- Department of Chemistry, University of Zurich, CH-8057 Zurich, Switzerland
| | - Evangelos Balanikas
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Arnulf Rosspeintner
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Zhiquan Li
- Institute of Applied Synthetic Chemistry, Division of Macromolecular Chemistry, Vienna University of Technology, Getreidemarkt 9/163/MC, 1060 Vienna, Austria
| | - Robert Liska
- Institute of Applied Synthetic Chemistry, Division of Macromolecular Chemistry, Vienna University of Technology, Getreidemarkt 9/163/MC, 1060 Vienna, Austria
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
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3
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Balanikas E, Reymond-Joubin M, Vauthey E. Excited-State Symmetry Breaking in Solvent Mixtures. J Phys Chem Lett 2024; 15:2447-2452. [PMID: 38407054 DOI: 10.1021/acs.jpclett.4c00213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
A large number of multipolar dyes undergo excited-state symmetry breaking (ESSB) in polar media. During this process, electronic excitation, initially distributed evenly over the molecule, localizes, at least partially, on one donor-acceptor branch. To resolve its initial stage, ESSB is investigated with a donor-acceptor-donor dye in binary mixtures of nonpolar and polar solvents using time-resolved infrared absorption spectroscopy. The presence of a few polar molecules around the dye is sufficient to initiate ESSB. Although the extent of asymmetry in a mixture is close to that in a pure solvent of similar polarity, the dynamics are slower and involve translational diffusion. However, preferential solvation in the mixtures leads to a larger local polarity. Furthermore, inhomogeneous broadening of the S1 ← S0 absorption band of the dye is observed in the mixtures, allowing for a photoselection of solutes with different local environments and ESSB dynamics.
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Affiliation(s)
- Evangelos Balanikas
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Maric Reymond-Joubin
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
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Verma P, Tasior M, Roy P, Meech SR, Gryko DT, Vauthey E. Excited-state symmetry breaking in quadrupolar pull-push-pull molecules: dicyanovinyl vs. cyanophenyl acceptors. Phys Chem Chem Phys 2023; 25:22689-22699. [PMID: 37602791 PMCID: PMC10467566 DOI: 10.1039/d3cp02810k] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/02/2023] [Indexed: 08/22/2023]
Abstract
A significant number of quadrupolar dyes behave as their dipolar analogues when photoexcited in polar environments. This is due to the occurrence of excited-state symmetry breaking (ES-SB), upon which the electronic excitation, initially distributed over the whole molecule, localises preferentially on one side. Here, we investigate the ES-SB properties of two A-D-A dyes, consisting of a pyrrolo-pyrrole donor (D) and either cyanophenyl or dicyanovinyl acceptors (A). For this, we use time-resolved vibrational spectroscopy, comparing IR absorption and femtosecond stimulated Raman spectroscopies. Although dicyanovinyl is a stronger electron-withdrawing group, ES-SB is not observed with the dicyanovinyl-based dye even in highly polar media, whereas it already takes place in weakly polar solvents with dyes containing cyanophenyl accepting groups. This difference is attributed to the large electronic coupling between the D-A branches in the former dye, whose loss upon symmetry breaking cannot be counterbalanced by a gain in solvation energy. Comparison with analogues of the cyanophenyl-based dye containing different spacers reveals that interbranch coupling does not so much depend on the distance between the D-A subunits than on the nature of the spacer. We show that transient Raman spectra probe different modes of these centrosymmetric molecules but are consistent with the transient IR data. However, lifetime broadening of the Raman bands, probably due to the resonance enhancement, may limit the application of this technique for monitoring ES-SB.
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Affiliation(s)
- Pragya Verma
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211, Geneva 4, Switzerland.
| | - Mariusz Tasior
- Institute of Organic Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
| | - Palas Roy
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Stephen R Meech
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Daniel T Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211, Geneva 4, Switzerland.
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Cesaretti A, Calzoni E, Montegiove N, Bianconi T, Alebardi M, La Serra MA, Consiglio G, Fortuna CG, Elisei F, Spalletti A. Lighting-Up the Far-Red Fluorescence of RNA-Selective Dyes by Switching from Ortho to Para Position. Int J Mol Sci 2023; 24:ijms24054812. [PMID: 36902248 PMCID: PMC10003335 DOI: 10.3390/ijms24054812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 02/13/2023] [Accepted: 02/15/2023] [Indexed: 03/06/2023] Open
Abstract
Fluorescence imaging is constantly searching for new far-red emitting probes whose turn-on response is selective upon the interaction with specific biological targets. Cationic push-pull dyes could indeed respond to these requirements due to their intramolecular charge transfer (ICT) character, by which their optical properties can be tuned, and their ability to interact strongly with nucleic acids. Starting from the intriguing results recently achieved with some push-pull dimethylamino-phenyl dyes, two isomers obtained by switching the cationic electron acceptor head (either a methylpyridinium or a methylquinolinium) from the ortho to the para position have been scrutinized for their ICT dynamics, their affinity towards DNA and RNA, and in vitro behavior. By exploiting the marked fluorescence enhancement observed upon complexation with polynucleotides, fluorimetric titrations were employed to evaluate the dyes' ability as efficient DNA/RNA binders. The studied compounds exhibited in vitro RNA-selectivity by localizing in the RNA-rich nucleoli and within the mitochondria, as demonstrated by fluorescence microscopy. The para-quinolinium derivative showed some modest antiproliferative effect on two tumor cell lines as well as improved properties as an RNA-selective far-red probe in terms of both turn-on response (100-fold fluorescence enhancement) and localized staining ability, attracting interest as a potential theranostic agent.
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Affiliation(s)
- Alessio Cesaretti
- Department of Chemistry, Biology and Biotechnology and Center of Excellence on Innovative Nanostructured Materials (CEMIN), University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy
- Correspondence:
| | - Eleonora Calzoni
- Department of Chemistry, Biology and Biotechnology and Center of Excellence on Innovative Nanostructured Materials (CEMIN), University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy
| | - Nicolò Montegiove
- Department of Chemistry, Biology and Biotechnology and Center of Excellence on Innovative Nanostructured Materials (CEMIN), University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy
| | - Tommaso Bianconi
- Department of Chemistry, Biology and Biotechnology and Center of Excellence on Innovative Nanostructured Materials (CEMIN), University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy
| | - Martina Alebardi
- Department of Chemistry, Biology and Biotechnology and Center of Excellence on Innovative Nanostructured Materials (CEMIN), University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy
| | - Maria Antonietta La Serra
- Department of Chemistry, Biology and Biotechnology and Center of Excellence on Innovative Nanostructured Materials (CEMIN), University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy
| | - Giuseppe Consiglio
- Department of Chemical Sciences, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Cosimo Gianluca Fortuna
- Department of Chemical Sciences, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Fausto Elisei
- Department of Chemistry, Biology and Biotechnology and Center of Excellence on Innovative Nanostructured Materials (CEMIN), University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy
| | - Anna Spalletti
- Department of Chemistry, Biology and Biotechnology and Center of Excellence on Innovative Nanostructured Materials (CEMIN), University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy
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Fakis M, Petropoulos V, Hrobárik P, Nociarová J, Osuský P, Maiuri M, Cerullo G. Exploring Solvent and Substituent Effects on the Excited State Dynamics and Symmetry Breaking of Quadrupolar Triarylamine End-Capped Benzothiazole Chromophores by Femtosecond Spectroscopy. J Phys Chem B 2022; 126:8532-8543. [PMID: 36256786 DOI: 10.1021/acs.jpcb.2c03103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We investigate herein the excited state dynamics and symmetry breaking processes in three benzothiazole-derived two-photon absorbing chromophores by femtosecond fluorescence and transient absorption (fs-TA) spectroscopies in solvents of various polarity. The chromophores feature a quasi-quadrupolar D-π-A-π-D architecture comprised of an electron-withdrawing benzothiazole core and lateral triphenylamine donors (Qbtz-H), while the acceptor strength of the central unit is enforced by attached cyano groups (Qbtz-CN) and the electron-donating strength of the arylamine moieties by introduction of peripheral methoxy groups (Qbtz'-CN). Steady state spectroscopy reveals positive solvatochromism, which is mostly pronounced for Qbtz'-CN. Femtosecond spectroscopy of Qbtz-H reveals the coexistence of the Franck-Condon (FC) state and states populated after symmetry breaking (SB) in low-polarity solvents such as toluene and tetrahydrofuran, while the SB state becomes favorable in polar acetonitrile. For the other two molecules possessing a stronger electron-accepting unit and thus more polar excited state, SB takes place even in low-polarity solvents, as shown by fs-TA spectroscopy. Global fitting of the fs-TA spectra together with investigation of the evolution associated spectra (EAS) reveals the existence of an initial FC state in Qbtz-H, in all studied solvents, which relaxes toward Intermediate Charge Transfer (I-CT) and SB states. On the other hand, for Qbtz-CN and Qbtz'-CN in more polar solvents, the FC state undergoes ultrafast relaxation toward symmetry-broken charge transfer (SB-CT) states which in turn show very fast recombination to the ground state. Our measurements confirm that the extent of symmetry breaking is larger for D-π-A-π-D systems with the stronger acceptor core and increases further by increasing electron-donating strength of triarylamine moieties, giving rise to symmetry breaking in these nonionic quadrupolar molecules with ethynylene (triple bond) π-spacers also in less polar solvents.
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Affiliation(s)
- Mihalis Fakis
- Department of Physics, University of Patras, PatrasGR-26500, Greece
| | - Vasilis Petropoulos
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133Milan, Italy
| | - Peter Hrobárik
- Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, SK-84215Bratislava, Slovakia
| | - Jela Nociarová
- Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, SK-84215Bratislava, Slovakia
| | - Patrik Osuský
- Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, SK-84215Bratislava, Slovakia
| | - Margherita Maiuri
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133Milan, Italy
| | - Giulio Cerullo
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133Milan, Italy
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Wang W, Xu X, Yang Z. Effects of linkage between donors on photoinduced charge transfer in one-photon and two-photon absorption of Donor-π-Donor-π-Acceptor conjugates. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 275:121179. [PMID: 35344857 DOI: 10.1016/j.saa.2022.121179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 03/11/2022] [Accepted: 03/19/2022] [Indexed: 06/14/2023]
Abstract
Photoinduced charge transfer (CT) mechanisms of two Donor-π-Donor-π-Acceptor conjugates composed of ferrocene (Fc), zinc-porphyrin (ZnP), and fullerene (C60) linked by phenylene-acetylene/acetylene during the one- (OPA) and the two-photon absorption (TPA) processes are analyzed theoretically based on the density functional theory calculations and visualization methods to study the effects of linkage between the two donors on the excitation characteristics. The change of bridge affects the efficiency of superexchange CT from Fc to ZnP in the OPA process. The one-photon excitations are dominated by local transitions of ZnP and Fc, and there is almost no efficient CT from the donors to the acceptor for both the two researched structures. In contrast, the advantage of superexchange CT from ZnP to C60 becomes much larger than the other transition forms during the TPA process when the linkage between ZnP and Fc is changed from acetylene to phenylene-acetylene. This linkage effect in TPA would have great significance in designing novel optoelectronic devices.
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Affiliation(s)
- Wenjun Wang
- School of Science, Dalian Maritime University, Dalian 116026, China
| | - Xuesong Xu
- School of Science, Dalian Maritime University, Dalian 116026, China.
| | - Zijiang Yang
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, China.
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Vauthey E. Watching Excited-State Symmetry Breaking in Multibranched Push-Pull Molecules. J Phys Chem Lett 2022; 13:2064-2071. [PMID: 35212550 DOI: 10.1021/acs.jpclett.2c00259] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The emissive properties of symmetric molecules containing several donor-acceptor branches are often similar to those of the single-branched analogues. This is due to the at least partial localization of the excitation on one branch. Detailed understanding of this excited-state symmetry breaking (ES-SB) requires the ability to monitor this process in real time. Over the past few years, several spectroscopic approaches were shown to enable visualization of ES-SB and of its dynamics. They include the detection of new vibrational or electronic absorption bands associated with transitions that are forbidden in the symmetric excited state. Alternatively, ES-SB can be detected by observing transitions that become weaker or vanish upon localization of the excitation. Herein, we discuss these different approaches as well as their merits and weaknesses.
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Affiliation(s)
- Eric Vauthey
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
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Singh D, Shewale D, Sengupta A, Soppina V, Kanvah S. Lutidine Derivatives for Live-Cell Imaging of Mitochondria and Endoplasmic Reticulum. Org Biomol Chem 2022; 20:7047-7055. [DOI: 10.1039/d2ob00995a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mitochondria and endoplasmic reticulum (ER) are highly dynamic subcellular structures essential for several biological functions. The development of non-toxic, wash-free fluorophores to visualize these structures inside cells aid in understanding...
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