1
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Xu C, Lin C, Peng J, Zhang J, Lin S, Gu FL, Gelin MF, Lan Z. On-the-fly simulation of time-resolved fluorescence spectra and anisotropy. J Chem Phys 2024; 160:104109. [PMID: 38477337 DOI: 10.1063/5.0201204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024] Open
Abstract
We combine on-the-fly trajectory surface hopping simulations and the doorway-window representation of nonlinear optical response functions to create an efficient protocol for the evaluation of time- and frequency-resolved fluorescence (TFRF) spectra and anisotropies of the realistic polyatomic systems. This approach gives the effective description of the proper (e.g., experimental) pulse envelopes, laser field polarizations, and the proper orientational averaging of TFRF signals directly from the well-established on-the-fly nonadiabatic dynamic simulations without extra computational cost. To discuss the implementation details of the developed protocol, we chose cis-azobenzene as a prototype to simulate the time evolution of the TFRF spectra governed by its nonadiabatic dynamics. The results show that the TFRF is determined by the interplay of several key factors, i.e., decays of excited-state populations, evolution of the transition dipole moments along with the dynamic propagation, and scaling factor of the TFRF signals associated with the cube of emission frequency. This work not only provides an efficient and effective approach to simulate the TFRF and anisotropies of realistic polyatomic systems but also discusses the important relationship between the TFRF signals and the underlining nonadiabatic dynamics.
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Affiliation(s)
- Chao Xu
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
| | - Congru Lin
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
| | - Jiawei Peng
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
| | - Juanjuan Zhang
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
| | - Shichen Lin
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-Park, Fukuoka 816-8580, Japan
| | - Feng Long Gu
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
| | - Maxim F Gelin
- School of Science, Hangzhou Dianzi University, Hangzhou 310018, People's Republic of China
| | - Zhenggang Lan
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
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2
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Titov E. Visible Light Induced Exciton Dynamics and trans-to- cis Isomerization in Azobenzene Aggregates: Insights from Surface Hopping/Semiempirical Configuration Interaction Molecular Dynamics Simulations. ACS OMEGA 2024; 9:8520-8532. [PMID: 38405525 PMCID: PMC10882624 DOI: 10.1021/acsomega.3c09900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 02/27/2024]
Abstract
Assemblies of photochromic molecules feature exciton states, which govern photochemical and photophysical processes in multichromophoric systems. Understanding the photoinduced dynamics of the assemblies requires nonadiabatic treatment involving multiple exciton states and numerous nuclear degrees of freedom, thus posing a challenge for simulations. In this work, we address this challenge for aggregates of azobenzene, a prototypical molecular switch, performing on-the-fly surface hopping calculations combined with semiempirical configuration interaction electronic structure and augmented with transition density matrix analysis to characterize exciton evolution. Specifically, we consider excitation of azobenzene tetramers in the nπ* absorption band located in the visible (blue) part of the electromagnetic spectrum, thus extending our recent work on dynamics after ππ* excitation corresponding to the ultraviolet region [Titov, J. Phys. Chem. C2023, 127, 13678-13688]. We find that the nπ* excitons, which are initially strongly localized by ground-state conformational disorder, undergo further (very strong) localization during short-time photodynamics. This excited-state localization process is extremely ultrafast, occurring within the first 10 fs of photodynamics. We observe virtually no exciton transfer of the localized excitons in the nπ* manifold. However, the transfer may occur via secondary pathways involving ππ* states or the ground state. Moreover, we find that the nπ* quantum yields of the trans-to-cis isomerization are reduced in the aggregated state.
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Affiliation(s)
- Evgenii Titov
- Institute of Chemistry, Theoretical
Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
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3
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Titov E, Beqiraj A. Exciton States of Azobenzene Aggregates: A First‐Principles Study. ADVANCED THEORY AND SIMULATIONS 2023. [DOI: 10.1002/adts.202200907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/22/2023]
Affiliation(s)
- Evgenii Titov
- University of Potsdam, Institute of Chemistry, Theoretical Chemistry Karl‐Liebknecht‐Straße 24‐25 14476 Potsdam Germany
| | - Alkit Beqiraj
- University of Potsdam, Institute of Chemistry, Theoretical Chemistry Karl‐Liebknecht‐Straße 24‐25 14476 Potsdam Germany
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4
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Titov E. Effect of conformational disorder on exciton states of an azobenzene aggregate. Phys Chem Chem Phys 2022; 24:24002-24006. [PMID: 36178007 DOI: 10.1039/d2cp02774g] [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
Azobenzene is a prototypical molecular photoswitch, widely used to trigger a variety of transformations at different length scales. In systems like self-assembled monolayers or micelles, azobenzene chromophores may interact with each other, which gives rise to the emergence of exciton states. Here, using first-principles calculations, we investigate how conformational disorder (induced, e.g., by thermal fluctuations) affects localization of these states, on an example of an H-type azobenzene tetramer. We find that conformational disorder leads to (partial) exciton localization on a single-geometry level, whereas ensemble-averaging results in a delocalized picture. The ππ* and nπ* excitons at high and low temperatures are discussed.
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Affiliation(s)
- Evgenii Titov
- Theoretical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany.
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5
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Titov E, Kopp T, Hoche J, Humeniuk A, Mitrić R. (De)localization dynamics of molecular excitons: comparison of mixed quantum–classical and fully quantum treatments. Phys Chem Chem Phys 2022; 24:12136-12148. [DOI: 10.1039/d2cp00586g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular excitons play a central role in processes of solar energy conversion, both natural and artificial. It is therefore no wonder that numerous experimental and theoretical investigations in the last...
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6
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Lee TH, Han GY, Yi MB, Shin JH, Kim HJ. Photoresponsive, switchable, pressure-sensitive adhesives: influence of UV intensity and hydrocarbon chain length of low molecular weight azobenzene compounds. RSC Adv 2021; 11:37392-37402. [PMID: 35496405 PMCID: PMC9043784 DOI: 10.1039/d1ra06596c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/12/2021] [Indexed: 11/26/2022] Open
Abstract
Unlike traditional adhesives with a fixed adhesive force, switchable adhesives, which have an adhesive force that can be adjusted by external stimuli, are specifically designed to be released according to user demand, or to enable the transfer of fine electronic devices. Previously developed switchable adhesives have limitations such as a slow switching rate, narrow adhesion modulation range, or the lack of reusability. Thus, we fabricated switchable pressure-sensitive adhesives (PSAs) that can overcome these limitations. The adhesive force of each switchable PSA, which comprises an azobenzene-containing acrylic polymer and low molecular weight compounds, was designed to be activated/deactivated via ultraviolet (UV) and visible light irradiation. The adhesive force and UV intensity required for the switch were found to be dependent on the aliphatic chain length of the compound. The adhesive force of the SP-C10, i.e., a switchable PSA containing a azobenzene compound with an aliphatic chain of 10 hydrocarbons, increased to 3.5 N from nearly zero in response to only 30 s of low-level (25 mW cm−2) UV irradiation. Additionally, SP-C10 did not lose its adhesive force even after 30 cycles of repeated adhesion switching. The mechanism of adhesion switching influenced by UV intensity and the structure of low molecular weight azobenzene compounds are also reported. A photoresponsive switchable pressure-sensitive adhesive (PSA) was fabricated with an azobenzene-containing polymer and low molecular weight compounds. Its adhesion force was activated/deactivated rapidly by UV/visible light irradiation.![]()
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Affiliation(s)
- Tae-Hyung Lee
- Laboratory of Adhesion and Bio-Composites, Program in Environmental Materials Science, Department of Agriculture, Forestry and Bioresources, Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Gi-Yeon Han
- Laboratory of Adhesion and Bio-Composites, Program in Environmental Materials Science, Department of Agriculture, Forestry and Bioresources, Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Mo-Beom Yi
- Laboratory of Adhesion and Bio-Composites, Program in Environmental Materials Science, Department of Agriculture, Forestry and Bioresources, Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Jae-Ho Shin
- Laboratory of Adhesion and Bio-Composites, Program in Environmental Materials Science, Department of Agriculture, Forestry and Bioresources, Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
| | - Hyun-Joong Kim
- Laboratory of Adhesion and Bio-Composites, Program in Environmental Materials Science, Department of Agriculture, Forestry and Bioresources, Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea .,Research Institute of Agriculture and Life Sciences, Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Republic of Korea
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7
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Titov E, Sharma A, Lomadze N, Saalfrank P, Santer S, Bekir M. Photoisomerization of an Azobenzene‐Containing Surfactant Within a Micelle. CHEMPHOTOCHEM 2021. [DOI: 10.1002/cptc.202100103] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Evgenii Titov
- Theoretical Chemistry Institute of Chemistry University of Potsdam Karl-Liebknecht-Straße 24–25 14476 Potsdam Germany
| | - Anjali Sharma
- Experimental Physics Institute of Physics and Astronomy University of Potsdam Karl-Liebknecht-Straße 24–25 14476 Potsdam Germany
| | - Nino Lomadze
- Experimental Physics Institute of Physics and Astronomy University of Potsdam Karl-Liebknecht-Straße 24–25 14476 Potsdam Germany
| | - Peter Saalfrank
- Theoretical Chemistry Institute of Chemistry University of Potsdam Karl-Liebknecht-Straße 24–25 14476 Potsdam Germany
| | - Svetlana Santer
- Experimental Physics Institute of Physics and Astronomy University of Potsdam Karl-Liebknecht-Straße 24–25 14476 Potsdam Germany
| | - Marek Bekir
- Experimental Physics Institute of Physics and Astronomy University of Potsdam Karl-Liebknecht-Straße 24–25 14476 Potsdam Germany
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8
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Titov E, Hummert J, Ikonnikov E, Mitrić R, Kornilov O. Electronic relaxation of aqueous aminoazobenzenes studied by time-resolved photoelectron spectroscopy and surface hopping TDDFT dynamics calculations. Faraday Discuss 2021; 228:226-241. [PMID: 33586720 DOI: 10.1039/d0fd00111b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Studies of ultrafast relaxation of molecular chromophores are complicated by the fact that most chromophores of biological and technological importance are rather large molecules and are strongly affected by their environment, either solvent or a protein cage. Here we present an approach which allows us to follow transient electronic structure of complex photoexcited molecules. We use the method of time-resolved photoelectron spectroscopy in solution to follow relaxation of two prototypical aqueous chromophores, Methyl Orange and Metanil Yellow, both of which are aminoazobenzene derivatives. Using excitation by 400 nm laser pulses and ionization by wavelength-selected 46.7 nm XUV pulses from high-order harmonic generation we follow relaxation of both molecules via the dark S1 state. The photoelectron spectra yield binding energies of both ground and excited states. We combine the experimental results with surface hopping time-dependent density functional theory (TDDFT) calculations employing B3LYP+D3 and ωB97X-D functionals. The results demonstrate that the method is generally suitable for description of ultrafast dynamics in these molecules and can recover absolute binding energies observed in the experiment. The B3LYP+D3 functional appears to be better suited for these systems, especially in the case of Metanil Yellow, where it indicates the importance of an intramolecular charge transfer state. Our results pave the way towards quantitative understanding of evolving electronic structure in photo-induced relaxation processes.
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Affiliation(s)
- Evgenii Titov
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg, Emil-Fischer-Straße 42, 97074 Würzburg, Germany.
| | - Johan Hummert
- Max Born Institute, Max-Born-Straße 2A, 12489 Berlin, Germany.
| | | | - Roland Mitrić
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg, Emil-Fischer-Straße 42, 97074 Würzburg, Germany.
| | - Oleg Kornilov
- Max Born Institute, Max-Born-Straße 2A, 12489 Berlin, Germany.
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9
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Titov E. On the Low-Lying Electronically Excited States of Azobenzene Dimers: Transition Density Matrix Analysis. MOLECULES (BASEL, SWITZERLAND) 2021; 26:molecules26144245. [PMID: 34299521 PMCID: PMC8303869 DOI: 10.3390/molecules26144245] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/08/2021] [Accepted: 07/09/2021] [Indexed: 11/16/2022]
Abstract
Azobenzene-containing molecules may associate with each other in systems such as self-assembled monolayers or micelles. The interaction between azobenzene units leads to a formation of exciton states in these molecular assemblies. Apart from local excitations of monomers, the electronic transitions to the exciton states may involve charge transfer excitations. Here, we perform quantum chemical calculations and apply transition density matrix analysis to quantify local and charge transfer contributions to the lowest electronic transitions in azobenzene dimers of various arrangements. We find that the transitions to the lowest exciton states of the considered dimers are dominated by local excitations, but charge transfer contributions become sizable for some of the lowest ππ* electronic transitions in stacked and slip-stacked dimers at short intermolecular distances. In addition, we assess different ways to partition the transition density matrix between fragments. In particular, we find that the inclusion of the atomic orbital overlap has a pronounced effect on quantifying charge transfer contributions if a large basis set is used.
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Affiliation(s)
- Evgenii Titov
- Theoretical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
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10
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Horsley JR, Wang X, Yu J, Abell AD. Exploiting conformationally gated electron transfer in self-assembled azobenzene-containing cyclic peptides using light. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.138232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Abstract
![]()
In nature, light is harvested by photoactive proteins to drive
a range of biological processes, including photosynthesis, phototaxis,
vision, and ultimately life. Bacteriorhodopsin, for example, is a
protein embedded within archaeal cell membranes that binds the chromophore
retinal within its hydrophobic pocket. Exposure to light triggers
regioselective photoisomerization of the confined retinal, which in
turn initiates a cascade of conformational changes within the protein,
triggering proton flux against the concentration gradient, providing
the microorganisms with the energy to live. We are inspired by these
functions in nature to harness light energy using synthetic photoswitches
under confinement. Like retinal, synthetic photoswitches require some
degree of conformational flexibility to isomerize. In nature, the
conformational change associated with retinal isomerization is accommodated
by the structural flexibility of the opsin host, yet it results in
steric communication between the chromophore and the protein. Similarly,
we strive to design systems wherein isomerization of confined photoswitches
results in steric communication between a photoswitch and its confining
environment. To achieve this aim, a balance must be struck between
molecular crowding and conformational freedom under confinement: too
much crowding prevents switching, whereas too much freedom resembles
switching of isolated molecules in solution, preventing communication. In this Account, we discuss five classes of synthetic light-switchable
compounds—diarylethenes, anthracenes, azobenzenes, spiropyrans,
and donor–acceptor Stenhouse adducts—comparing their
behaviors under confinement and in solution. The environments employed
to confine these photoswitches are diverse, ranging from planar surfaces
to nanosized cavities within coordination cages, nanoporous frameworks,
and nanoparticle aggregates. The trends that emerge are primarily
dependent on the nature of the photoswitch and not on the material
used for confinement. In general, we find that photoswitches requiring
less conformational freedom for switching are, as expected, more straightforward
to isomerize reversibly under confinement. Because these compounds
undergo only small structural changes upon isomerization, however,
switching does not propagate into communication with their environment.
Conversely, photoswitches that require more conformational freedom
are more challenging to switch under confinement but also can influence
system-wide behavior. Although we are primarily interested in
the effects of geometric
constraints on photoswitching under confinement, additional effects
inevitably emerge when a compound is removed from solution and placed
within a new, more crowded environment. For instance, we have found
that compounds that convert to zwitterionic isomers upon light irradiation
often experience stabilization of these forms under confinement. This
effect results from the mutual stabilization of zwitterions that are
brought into close proximity on surfaces or within cavities. Furthermore,
photoswitches can experience preorganization under confinement, influencing
the selectivity and efficiency of their photoreactions. Because intermolecular
interactions arising from confinement cannot be considered independently
from the effects of geometric constraints, we describe all confinement
effects concurrently throughout this Account.
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Affiliation(s)
- Angela B. Grommet
- Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Lucia M. Lee
- Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Rafal Klajn
- Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
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12
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Riaz S, Friedrichs G. Vibrational sum-frequency generation study of molecular structure, sterical constraints and nonlinear optical switching contrast of mixed alkyl-azobenzene self-assembled monolayers. Z PHYS CHEM 2020. [DOI: 10.1515/zpch-2020-1655] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Abstract
Self-assembled monolayers (SAMs) of azobenzene (AB) functionalized alkyl thiols on gold diluted with simple alkyl thiols provide a straightforward way to photochromic surfaces with high and tunable photoswitching efficiency. Trans-cis isomerization of the AB molecule changes the physical properties of the surface, including the nonlinear optical (NLO) response. Vibrational sum-frequency generation (VSFG) spectroscopy as a nonlinear type of laser spectroscopy offers surface- and orientation-sensitive insight into the molecular structure of mixed SAMs. In this study, VSFG as well as ultraviolet-visible (UV/Vis) spectroscopy has been employed to investigate the morphology, molecular structure, and NLO response of mixed SAMs with systematically varied surface composition. Methylazobenzene (MeAB) has been used as the molecular switch with the methyl substituent serving as orientational VSFG marker. Both short-chain and long-chain alkyl thiol co-ligands have been used to gain insight into the interplay between SAM structure and sterical constraints that are known to limit the free switching volume. Underlining the dominating role of sterical effects for controlling photochromic properties, a strong inhibition of the photoswitching efficiency and NLO response has been observed for the SAMs with an alkyl thiol co-ligand long enough to spatially extend into the layer of the MeAB chromophore. Overall, with <12% signal change, the relative NLO switching contrasts remained low in all cases. VSFG spectral trends clearly revealed that the presumably higher photoswitching efficiency upon dilution with the co-ligand is counteracted by a loss of structural order of the chromophore.
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Affiliation(s)
- Saira Riaz
- Islamabad College for Girls , F-6/2 , Islamabad, 44000 , Pakistan
| | - Gernot Friedrichs
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel , Max-Eyth-Str. 1, 24118 , Kiel , Germany
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13
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Fuentes E, Gerth M, Berrocal JA, Matera C, Gorostiza P, Voets IK, Pujals S, Albertazzi L. An Azobenzene-Based Single-Component Supramolecular Polymer Responsive to Multiple Stimuli in Water. J Am Chem Soc 2020; 142:10069-10078. [PMID: 32395995 PMCID: PMC7497294 DOI: 10.1021/jacs.0c02067] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
![]()
One
of the most appealing features of supramolecular assemblies
is their ability to respond to external stimuli due to their noncovalent
nature. This provides the opportunity to gain control over their size,
morphology, and chemical properties and is key toward some of their
applications. However, the design of supramolecular systems able to
respond to multiple stimuli in a controlled fashion is still challenging.
Here we report the synthesis and characterization of a novel discotic
molecule, which self-assembles in water into a single-component supramolecular
polymer that responds to multiple independent stimuli. The building
block of such an assembly is a C3-symmetric
monomer, consisting of a benzene-1,3,5-tricarboxamide core conjugated
to a series of natural and non-natural functional amino acids. This
design allows the use of rapid and efficient solid-phase synthesis
methods and the modular implementation of different functionalities.
The discotic monomer incorporates a hydrophobic azobenzene moiety,
an octaethylene glycol chain, and a C-terminal lysine. Each of these
blocks was chosen for two reasons: to drive the self-assembly in water
by a combination of H-bonding and hydrophobicity and to impart specific
responsiveness. With a combination of microscopy and spectroscopy
techniques, we demonstrate self-assembly in water and responsiveness
to temperature, light, pH, and ionic strength. This work shows the
potential to integrate independent mechanisms for controlling self-assembly
in a single-component supramolecular polymer by the rational monomer
design and paves the way toward the use of multiresponsive systems
in water.
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Affiliation(s)
- Edgar Fuentes
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona 08036, Spain
| | - Marieke Gerth
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry & Institute of Complex Molecular Systems (ICMS), Eindhoven University of Technology (TUE), Eindhoven 5612 AZ, The Netherlands.,Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology (TUE), Eindhoven 5612 AZ, The Netherlands
| | - José Augusto Berrocal
- Adolphe Merkle Institute, Polymer Chemistry and Materials, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Carlo Matera
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona 08036, Spain.,Network Biomedical Research Centre in Biomaterials, Bioengineering and Nanomedicine (CIBER-BBN), Madrid 28029, Spain
| | - Pau Gorostiza
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona 08036, Spain.,Network Biomedical Research Centre in Biomaterials, Bioengineering and Nanomedicine (CIBER-BBN), Madrid 28029, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona 08011, Spain
| | - Ilja K Voets
- Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology (TUE), Eindhoven 5612 AZ, The Netherlands
| | - Silvia Pujals
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona 08036, Spain.,Department of Electronics and Biomedical Engineering, Faculty of Physics, Universitat de Barcelona, Barcelona 08011, Spain
| | - Lorenzo Albertazzi
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona 08036, Spain.,Department of Biomedical Engineering, Institute of Complex Molecular Systems (ICMS), Eindhoven University of Technology (TUE), Eindhoven 5612 AZ, The Netherlands
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14
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Pesce L, Perego C, Grommet AB, Klajn R, Pavan GM. Molecular Factors Controlling the Isomerization of Azobenzenes in the Cavity of a Flexible Coordination Cage. J Am Chem Soc 2020; 142:9792-9802. [PMID: 32353237 PMCID: PMC7644116 DOI: 10.1021/jacs.0c03444] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
Photoswitchable
molecules are employed for many applications, from
the development of active materials to the design of stimuli-responsive
molecular systems and light-powered molecular machines. To fully exploit
their potential, we must learn ways to control the mechanism and kinetics
of their photoinduced isomerization. One possible strategy involves
confinement of photoresponsive switches such as azobenzenes or spiropyrans
within crowded molecular environments, which may allow control over
their light-induced conversion. However, the molecular factors that
influence and control the switching process under realistic conditions
and within dynamic molecular regimes often remain difficult to ascertain.
As a case study, here we have employed molecular models to probe the
isomerization of azobenzene guests within a Pd(II)-based coordination
cage host in water. Atomistic molecular dynamics and metadynamics
simulations allow us to characterize the flexibility of the cage in
the solvent, the (rare) guest encapsulation and release events, and
the relative probability/kinetics of light-induced isomerization of
azobenzene analogues in these host–guest systems. In this way,
we can reconstruct the mechanism of azobenzene switching inside the
cage cavity and explore key molecular factors that may control this
event. We obtain a molecular-level insight on the effects of crowding
and host–guest interactions on azobenzene isomerization. The
detailed picture elucidated by this study may enable the rational
design of photoswitchable systems whose reactivity can be controlled
via host–guest interactions.
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Affiliation(s)
- Luca Pesce
- Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, Galleria 2, Via Cantonale 2c, CH-6928 Manno, Switzerland
| | - Claudio Perego
- Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, Galleria 2, Via Cantonale 2c, CH-6928 Manno, Switzerland
| | - Angela B Grommet
- Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Rafal Klajn
- Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Giovanni M Pavan
- Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, Galleria 2, Via Cantonale 2c, CH-6928 Manno, Switzerland.,Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
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15
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Giles LW, Marlow JB, Butler CSG, Turpin GA, de Campo L, Mudie ST, Faul CFJ, Tabor RF. Structural relationships for the design of responsive azobenzene-based lyotropic liquid crystals. Phys Chem Chem Phys 2020; 22:4086-4095. [PMID: 32031185 DOI: 10.1039/c9cp05463d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Light-responsive binary (azobenzene + solvent) lyotropic liquid crystals (LCs) were investigated by structural modification of simple azobenzene molecules. Three benzoic acid-containing azobenzene molecules 4-(4-(hydroxyphenyl)diazenyl)benzoic acid (AZO1), 3-(4-(hydroxyphenyl)diazenyl)benzoic acid (AZO2) and 5-(4-(hydroxyphenyl)diazenyl)isophthalic acid (AZO3) were produced with various amide substitutions to produce tectons with a variety of hydrophobicity, size and branching. The LC mesophases formed by binary (azobenzene + solvent) systems with low volatility solvents dimethylsulfoxide (DMSO) and N,N-dimethylformamide (DMF) as well as the protic ionic liquids ethylammonium formate (EAF) and propylammonium formate (PAF), were investigated using a combination of small-angle X-ray and neutron scattering (SAXS and SANS) as well as polarising light microscopy (PLM). Increasing alkyl group length was found to have a strong influence on LC phase spacing, and changes in the position of substitution on the benzene ring influenced the preferred curvature of phases. UV-induced trans to cis isomerization of the samples was shown to influence ordering and optical birefringence, indicating potential applications in optical devices.
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Affiliation(s)
- Luke W Giles
- School of Chemistry, Monash University, Clayton 3800, Victoria, Australia.
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16
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Titov E, Humeniuk A, Mitrić R. Comparison of moving and fixed basis sets for nonadiabatic quantum dynamics at conical intersections. Chem Phys 2020. [DOI: 10.1016/j.chemphys.2019.110526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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17
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Zhang TS, Li ZW, Fang Q, Barbatti M, Fang WH, Cui G. Stereoselective Excited-State Isomerization and Decay Paths in cis-Cyclobiazobenzene. J Phys Chem A 2019; 123:6144-6151. [DOI: 10.1021/acs.jpca.9b04372] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Teng-Shuo Zhang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Zi-Wen Li
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Qiu Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | | | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
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18
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Boumrifak C, Yang C, Bellotto S, Wegner HA, Wachtveitl J, Dreuw A, Slavov C. Isomerization Dynamics of Electronically Coupled but Thermodynamically Decoupled Bisazobenzenes. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201900077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Chokri Boumrifak
- Institute of Physical and Theoretical ChemistryGoethe University Frankfurt 60438 Germany
| | - Chong Yang
- Interdisciplinary Center for Scientific Computing (IWR)University of Heidelberg Heidelberg 69120 Germany
| | - Silvia Bellotto
- Center for Materials Research (LaMa)Justus Liebig University Giessen 35392 Germany
| | - Hermann A. Wegner
- Center for Materials Research (LaMa)Justus Liebig University Giessen 35392 Germany
| | - Josef Wachtveitl
- Institute of Physical and Theoretical ChemistryGoethe University Frankfurt 60438 Germany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing (IWR)University of Heidelberg Heidelberg 69120 Germany
| | - Chavdar Slavov
- Institute of Physical and Theoretical ChemistryGoethe University Frankfurt 60438 Germany
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19
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Bochicchio D, Kwangmettatam S, Kudernac T, Pavan GM. How Defects Control the Out-of-Equilibrium Dissipative Evolution of a Supramolecular Tubule. ACS NANO 2019; 13:4322-4334. [PMID: 30875196 DOI: 10.1021/acsnano.8b09523] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Supramolecular architectures that work out-of-equilibrium or that can change in specific ways when absorbing external energy are ubiquitous in nature. Gaining the ability to create via self-assembly artificial materials possessing such fascinating behaviors would have a major impact in many fields. However, the rational design of similar dynamic structures requires to understand and, even more challenging, to learn how to master the molecular mechanisms governing how the assembled systems evolve far from the equilibrium. Typically, this represents a daunting challenge due to the limited molecular insight that can be obtained by the experiments or by classical modeling approaches. Here we combine coarse-grained molecular models and advanced simulation approaches to study at submolecular (<5 Å) resolution a supramolecular tubule, which breaks and disassembles upon absorption of light energy triggering isomerization of its azobenzene-containing monomers. Our approach allows us to investigate the molecular mechanism of monomer transition in the assembly and to elucidate the kinetic process for the accumulation of the transitions in the system. Despite the stochastic nature of the excitation process, we demonstrate how these tubules preferentially dissipate the absorbed energy locally via the amplification of defects in their supramolecular structure. We find that this constitutes the best kinetic pathway for accumulating monomer transitions in the system, which determines the dynamic evolution out-of-equilibrium and the brittle behavior of the assembly under perturbed conditions. Thanks to the flexibility of our models, we finally come out with a general principle, where defects explain and control the brittle/soft behavior of such light-responsive assemblies.
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Affiliation(s)
- Davide Bochicchio
- Department of Innovative Technologies , University of Applied Sciences and Arts of Southern Switzerland , Galleria 2, Via Cantonale 2c , CH-6928 Manno , Switzerland
| | - Supaporn Kwangmettatam
- Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology , University of Twente , PO Box 207, 7500 AE Enschede , The Netherlands
| | - Tibor Kudernac
- Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology , University of Twente , PO Box 207, 7500 AE Enschede , The Netherlands
| | - Giovanni M Pavan
- Department of Innovative Technologies , University of Applied Sciences and Arts of Southern Switzerland , Galleria 2, Via Cantonale 2c , CH-6928 Manno , Switzerland
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20
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Maurer RJ, Reuter K. Computational design of metal-supported molecular switches: transient ion formation during light- and electron-induced isomerisation of azobenzene. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:044003. [PMID: 30523934 DOI: 10.1088/1361-648x/aaf0e1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In molecular nanotechnology, a single molecule is envisioned to act as the basic building block of electronic devices. Such devices may be of special interest for organic photovoltaics, data storage, and smart materials. However, more often than not the molecular function is quenched upon contact with a conducting support. Trial-and-error-based decoupling strategies via molecular functionalisation and change of substrate have in many instances proven to yield unpredictable results. The adsorbate-substrate interactions that govern the function can be understood with the help of first-principles simulation. Employing dispersion-corrected density-functional theory (DFT) and linear expansion delta-self-consistent-field DFT, the electronic structure of a prototypical surface-adsorbed functional molecule, namely azobenzene adsorbed to (1 1 1) single crystal facets of copper, silver and gold, is investigated and the main reasons for the loss or survival of the switching function upon adsorption are identified. The light-induced switching ability of a functionalised derivative of azobenzene on Au(1 1 1) and azobenzene on Ag(1 1 1) and Au(1 1 1) is assessed based on the excited-state potential energy landscapes of their transient molecular ions, which are believed to be the main intermediates of the experimentally observed isomerisation reaction. We provide a rationalisation of the experimentally observed function or lack thereof that connects to the underlying chemistry of the metal-surface interaction and provides insights into general design strategies for complex light-driven reactions at metal surfaces.
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Affiliation(s)
- Reinhard J Maurer
- Department of Chemistry, University of Warwick, Gibbet Hill Road, CV4 7AL, Coventry, United Kingdom
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21
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Nonadiabatic dynamics simulation of photoisomerization mechanism of photoswitch azodicarboxamide: Hydrogen bonding effects. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2018.08.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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22
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Fregoni J, Granucci G, Coccia E, Persico M, Corni S. Manipulating azobenzene photoisomerization through strong light-molecule coupling. Nat Commun 2018; 9:4688. [PMID: 30409994 PMCID: PMC6224570 DOI: 10.1038/s41467-018-06971-y] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 10/04/2018] [Indexed: 11/09/2022] Open
Abstract
The formation of hybrid light–molecule states (polaritons) offers a new strategy to manipulate the photochemistry of molecules. To fully exploit its potential, one needs to build a toolbox of polaritonic phenomenologies that supplement those of standard photochemistry. By means of a state-of-the-art computational photochemistry approach extended to the strong-coupling regime, here we disclose various mechanisms peculiar of polaritonic chemistry: coherent population oscillations between polaritons, quenching by trapping in dead-end polaritonic states and the alteration of the photochemical reaction pathway and quantum yields. We focus on azobenzene photoisomerization, that encompasses the essential features of complex photochemical reactions such as the presence of conical intersections and reaction coordinates involving multiple internal modes. In the strong coupling regime, a polaritonic conical intersection arises and we characterize its role in the photochemical process. Our chemically detailed simulations provide a framework to rationalize how the strong coupling impacts the photochemistry of realistic molecules. Manipulation of the photochemistry of molecules is traditionally achieved through synthetic chemical modifications. Here the authors use computational photochemistry to show how to control azobenzene photoisomerization through hybrid light–molecule states (polaritons).
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Affiliation(s)
- J Fregoni
- Dipartimento di Scienze Fisiche, Informatiche e Matematiche, University of Modena and Reggio Emilia, I-41125, Modena, Italy.,Istituto Nanoscienze, Consiglio Nazionale delle Ricerche CNR-NANO, I-41125, Modena, Italy
| | - G Granucci
- Dipartimento di Chimica e Chimica Industriale, University of Pisa, I-56124, Pisa, Italy.
| | - E Coccia
- Dipartimento di Scienze Chimiche, University of Padova, I-35131, Padova, Italy
| | - M Persico
- Dipartimento di Chimica e Chimica Industriale, University of Pisa, I-56124, Pisa, Italy
| | - S Corni
- Istituto Nanoscienze, Consiglio Nazionale delle Ricerche CNR-NANO, I-41125, Modena, Italy. .,Dipartimento di Scienze Chimiche, University of Padova, I-35131, Padova, Italy.
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23
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Torres A, Prado LR, Bortolini G, Rego LGC. Charge Transfer Driven Structural Relaxation in a Push-Pull Azobenzene Dye-Semiconductor Complex. J Phys Chem Lett 2018; 9:5926-5933. [PMID: 30257563 DOI: 10.1021/acs.jpclett.8b02490] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Photoexcited structural dynamics in azo-compounds may differ fundamentally whether the push-pull photochromic azo-compound is isolated or forms a heterogeneous charge transfer complex, due to a sudden oxidation of the chromophore. Herein, we use a quantum-classical self-consistent approach that incorporates nonadiabatic excited-state electronic quantum dynamics into molecular mechanics to study the photoexcited dynamics of the push-pull azo-compound para-Methyl Red in the gas phase and sensitizing the (101) anatase surface of TiO2. We find that the photoinduced S2/S0 trans-to- cis isomerization of para-Methyl Red in the gas phase occurs through a pedal-like torsion around the ϕCNNC dihedral angle, without evidence to support the inversion mechanism, likewise in the parent azobenzene molecule. However, the photoexcited structural relaxation of the charge transfer complex para-Methyl Red/TiO2 contrasts essentially with the isolated azo-compounds. Immediately after photoexcitation, the excited electron flows into the TiO2 conduction band, with an injection time constant of ≃5 fs, and no indication of isomerization is observed during the 1.5 ps simulations. Instead, a strong vibronic relaxation occurs that excites the NN stretching mode of the azo-group, which is ultimately ascribed to the NA relaxation, and delocalization, of the hole wavepacket.
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Affiliation(s)
- Alberto Torres
- Department of Physics , Universidade Federal de Santa Catarina , Florianópolis , SC 88040-900 , Brazil
| | - Luciano R Prado
- Department of Physics , Universidade Federal de Santa Catarina , Florianópolis , SC 88040-900 , Brazil
| | - Graziele Bortolini
- Department of Physics , Universidade Federal de Santa Catarina , Florianópolis , SC 88040-900 , Brazil
| | - Luis G C Rego
- Department of Physics , Universidade Federal de Santa Catarina , Florianópolis , SC 88040-900 , Brazil
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24
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Titov E, Humeniuk A, Mitrić R. Exciton localization in excited-state dynamics of a tetracene trimer: a surface hopping LC-TDDFTB study. Phys Chem Chem Phys 2018; 20:25995-26007. [PMID: 30298878 DOI: 10.1039/c8cp05240a] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Excitons in the molecular aggregates of chromophores are key participants in important processes such as photosynthesis or the functioning of organic photovoltaic devices. Therefore, the exploration of exciton dynamics is crucial. Here we report on exciton localization during excited-state dynamics of the recently synthesized tetracene trimer [Liu et al., Org. Lett., 2017, 19, 580]. We employ the surface hopping approach to nonadiabatic molecular dynamics in conjunction with the long-range corrected time-dependent density functional tight binding (LC-TDDFTB) method [Humeniuk and Mitrić, Comput. Phys. Commun., 2017, 221, 174]. Utilizing a set of descriptors based on the transition density matrix, we perform comprehensive analysis of exciton dynamics. The obtained results reveal an ultrafast exciton localization to a single tetracene unit of the trimer during excited-state dynamics, along with exciton transfer between units.
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Affiliation(s)
- Evgenii Titov
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg, Emil-Fischer-Straße 42, 97074 Würzburg, Germany.
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25
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Yang C, Slavov C, Wegner HA, Wachtveitl J, Dreuw A. Computational design of a molecular triple photoswitch for wavelength-selective control. Chem Sci 2018; 9:8665-8672. [PMID: 30627390 PMCID: PMC6289168 DOI: 10.1039/c8sc03379j] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 09/20/2018] [Indexed: 01/10/2023] Open
Abstract
meta-Trisazobenzenes allow for wavelength-selective photo-switching of the individual azobenzene branches.
A small single molecule with multiple photoswitchable subunits, selectively and independently controllable by light of different wavelengths, is highly attractive for applications in multi-responsive materials and biological sciences. Herein, triple photoswitches are presented consisting of three independent azobenzene (AB) subunits that share a common central phenyl ring: the meta-trisazobenzenes (MTA). It is the unique meta-connectivity pattern leading to decoupling of all azo-subunits although they do overlap spatially. Based on this pattern, we design a triple MTA photoswitch, as proof-of-principle, with three different, electronically independent AB branches on the computer, which can be individually photo-excited to trigger ultra-fast E → Z isomerization at the selected AB branch.
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Affiliation(s)
- Chong Yang
- Interdisciplinary Center for Scientific Computing , Heidelberg University , Im Neuenheimer Feld 205A , 69120 Heidelberg , Germany .
| | - Chavdar Slavov
- Institute for Physical and Theoretical Chemistry , Goethe University , Max-von-Laue Str. 7 , 60438 Frankfurt am Main , Germany
| | - Hermann A Wegner
- Institute of Organic Chemistry , Justus Liebig University Giessen , Heinrich-Buff-Ring 17 , 35392 Giessen , Germany
| | - Josef Wachtveitl
- Institute for Physical and Theoretical Chemistry , Goethe University , Max-von-Laue Str. 7 , 60438 Frankfurt am Main , Germany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing , Heidelberg University , Im Neuenheimer Feld 205A , 69120 Heidelberg , Germany .
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26
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Slavov C, Yang C, Heindl AH, Stauch T, Wegner HA, Dreuw A, Wachtveitl J. Twist and Return-Induced Ring Strain Triggers Quick Relaxation of a ( Z)-Stabilized Cyclobisazobenzene. J Phys Chem Lett 2018; 9:4776-4781. [PMID: 30063355 DOI: 10.1021/acs.jpclett.8b02159] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Continuous irradiation of the thermodynamically stable ( Z, Z)-cyclobisazobenzene does not lead to accumulation of a ( Z, E) or ( E, E) isomer as one might expect. Our combined experimental and computational investigation reveals that Z → E photoisomerization still takes place on an ultrafast time scale but induces large ring strain in the macrocycle, which leads to a very fast thermal back-isomerization, preventing photostationary accumulation of ( E)-isomers.
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Affiliation(s)
- Chavdar Slavov
- Institute of Physical and Theoretical Chemistry , Goethe University , Frankfurt 60323 , Germany
| | - Chong Yang
- Interdisciplinary Center for Scientific Computing (IWR) , University of Heidelberg , Heidelberg 69117 , Germany
| | - Andreas H Heindl
- Institute of Organic Chemistry , Justus Liebig University , Giessen 35390 , Germany
| | - Tim Stauch
- Interdisciplinary Center for Scientific Computing (IWR) , University of Heidelberg , Heidelberg 69117 , Germany
| | - Hermann A Wegner
- Institute of Organic Chemistry , Justus Liebig University , Giessen 35390 , Germany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing (IWR) , University of Heidelberg , Heidelberg 69117 , Germany
| | - Josef Wachtveitl
- Institute of Physical and Theoretical Chemistry , Goethe University , Frankfurt 60323 , Germany
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27
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Mondal P, Granucci G, Rastädter D, Persico M, Burghardt I. Azobenzene as a photoregulator covalently attached to RNA: a quantum mechanics/molecular mechanics-surface hopping dynamics study. Chem Sci 2018; 9:4671-4681. [PMID: 29899961 PMCID: PMC5969502 DOI: 10.1039/c8sc00072g] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 04/25/2018] [Indexed: 12/21/2022] Open
Abstract
Azobenzene covalently attached to RNA undergoes trans-to-cis photo-switching on a time scale of ∼15 picoseconds – 30 times slower than in vacuo.
The photoregulation of nucleic acids by azobenzene photoswitches has recently attracted considerable interest in the context of emerging biotechnological applications. To understand the mechanism of photoinduced isomerisation and conformational control in these complex biological environments, we employ a Quantum Mechanics/Molecular Mechanics (QM/MM) approach in conjunction with nonadiabatic Surface Hopping (SH) dynamics. Two representative RNA–azobenzene complexes are investigated, both of which contain the azobenzene chromophore covalently attached to an RNA double strand via a β-deoxyribose linker. Due to the pronounced constraints of the local RNA environment, it is found that trans-to-cis isomerization is slowed down to a time scale of ∼10–15 picoseconds, in contrast to 500 femtoseconds in vacuo, with a quantum yield reduced by a factor of two. By contrast, cis-to-trans isomerization remains in a sub-picosecond regime. A volume-conserving isomerization mechanism is found, similarly to the pedal-like mechanism previously identified for azobenzene in solution phase. Strikingly, the chiral RNA environment induces opposite right-handed and left-handed helicities of the ground-state cis-azobenzene chromophore in the two RNA–azobenzene complexes, along with an almost completely chirality conserving photochemical pathway for these helical enantiomers.
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Affiliation(s)
- Padmabati Mondal
- Institute of Physical and Theoretical Chemistry , Goethe University Frankfurt , Max-von-Laue-Str. 7 , 60438 Frankfurt , Germany . ;
| | - Giovanni Granucci
- Dipartimento di Chimica e Chimica Industriale , Università di Pisa , v. Moruzzi 13 , I-56124 Pisa , Italy .
| | - Dominique Rastädter
- Institute of Physical and Theoretical Chemistry , Goethe University Frankfurt , Max-von-Laue-Str. 7 , 60438 Frankfurt , Germany . ;
| | - Maurizio Persico
- Dipartimento di Chimica e Chimica Industriale , Università di Pisa , v. Moruzzi 13 , I-56124 Pisa , Italy .
| | - Irene Burghardt
- Institute of Physical and Theoretical Chemistry , Goethe University Frankfurt , Max-von-Laue-Str. 7 , 60438 Frankfurt , Germany . ;
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28
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Avanzini F, Moro GJ. Quantum stochastic trajectories: the Smoluchowski-Bohm equation. Phys Chem Chem Phys 2018; 20:165-179. [PMID: 29181466 DOI: 10.1039/c7cp06071h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Molecular systems are quantum systems, but the complete characterization of molecular motions within a fully quantum framework might appear to be an unfeasible task because it would require that the actual nuclear positions are established at any time. One would like to use a quantum molecular trajectory that defines the instantaneous nuclear positions and satisfies the predictions of quantum mechanics in terms of its statistical properties. Even though it can be proven that the single Bohm trajectory provides a representation of the quantum molecular trajectory, this solves the issue only on a theoretical ground: exact solutions of the Schrödinger-Bohm dynamical system are extremely computationally demanding. Therefore, we derive a stochastic equation of Smoluchowski type from the Schrödinger-Bohm dynamics, through projection operator techniques, in order to characterize the molecular motions of open quantum systems. The main quantum features of the motions emerge from the equilibrium distribution, i.e., the wave function's squared modulus integrated on the environment degrees of freedom. Furthermore, we verify the accuracy of the stochastic equation by comparing its predictions with those of the deterministic dynamics for a model system of six interacting harmonic oscillators. The indisputable advantage of this full quantum mechanical approach is that of representing the molecular dynamics, which controls important phenomena like vibrational relaxation, conformational transitions and activated processes, in a self consistent way and at the low computational cost of solving simple stochastic equations.
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Affiliation(s)
- Francesco Avanzini
- Dipartimento di Scienze Chimiche, Università di Padova, via Marzolo 1, 35131 Padova, Italy.
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29
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Montagna M, Guskova O. Photosensitive Cationic Azobenzene Surfactants: Thermodynamics of Hydration and the Complex Formation with Poly(methacrylic acid). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:311-321. [PMID: 29228776 DOI: 10.1021/acs.langmuir.7b03638] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In this computational work, we investigate the photosensitive cationic surfactants with the trimethylammonium or polyamine hydrophilic head and the azobenzene-containing hydrophobic tail. The azobenzene-based molecules are known to undergo a reversible trans-cis-trans isomerization reaction when subjected to UV-visible light irradiation. Combining the density functional theory and the all-atom molecular dynamics simulations, the structural and the hydration properties of the trans- and the cis-isomers and their interaction with the oppositely charged poly(methacrylic acid) in aqueous solution are investigated. We establish and quantify the correlations of the molecular structure and the isomerization state of the surfactants and their hydrophilicity/hydrophobicity and the self-assembling altered by light. For this reason, we compare the hydration free energies of the trans- and the cis-isomers. Moreover, the investigations of the interaction strength between the azobenzene molecules and the polyanion provide additional elucidations of the recent experimental and theoretical studies on the light triggered reversible deformation behavior of the microgels and the polymer brushes loaded with azobenzene surfactants.
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Affiliation(s)
- Maria Montagna
- Institute Theory of Polymers, Leibniz Institute of Polymer Research Dresden , Hohe Str. 6, D-01069 Dresden, Germany
| | - Olga Guskova
- Institute Theory of Polymers, Leibniz Institute of Polymer Research Dresden , Hohe Str. 6, D-01069 Dresden, Germany
- Dresden Center for Computational Materials Science (DCMS), Technische Universität Dresden , D-01062 Dresden, Germany
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30
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Abstract
Steric charge is an informative descriptor providing novel insights to appreciate the steric effect and stereoselectivity for chemical processes and transformations.
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Affiliation(s)
- Shubin Liu
- Research Computing Center, University of North Carolina
- Chapel Hill
- USA
| | - Lianghong Liu
- Department of Pharmacy, Hunan University of Medicine
- P. R. China
| | - Donghai Yu
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University
- P. R. China
| | - Chunying Rong
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University
- P. R. China
| | - Tian Lu
- Beijing Kein Research Center for Natural Sciences
- Beijing 100022
- P. R. China
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31
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Cocchi C, Draxl C. Understanding the effects of packing and chemical terminations on the optical excitations of azobenzene-functionalized self-assembled monolayers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:394005. [PMID: 28664870 DOI: 10.1088/1361-648x/aa7ca7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In a first-principles study based on many-body perturbation theory, we analyze the optical excitations of azobenzene-functionalized self-assembled monolayers (SAMs) with increasing packing density and different terminations, considering for comparison the corresponding gas-phase molecules and dimers. Intermolecular coupling increases with the density of the chromophores independently of the functional groups. The intense [Formula: see text] resonance that triggers photo-isomerization is present in the spectra of isolated dimers and diluted SAMs, but it is almost completely washed out in tightly packed architectures. Intermolecular coupling is partially inhibited by mixing differently functionalized azobenzene derivatives, in particular when large groups are involved. In this way, the excitation band inducing the photo-isomerization process is partially preserved and the effects of dense packing partly counterbalanced. Our results suggest that a tailored design of azobenzene-functionalized SAMs which optimizes the interplay between the packing density of the chromophores and their termination can lead to significant improvements in the photo-switching efficiency of these systems.
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Affiliation(s)
- Caterina Cocchi
- Physics Department and IRIS Adlershof, Humboldt-Universität zu Berlin, Berlin, Germany. European Theoretical Spectroscopic Facility (ETSF
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32
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Affiliation(s)
- Francesco Avanzini
- Dipartimento di Scienze Chimiche, Università di Padova, via Marzolo 1, 35131 Padova, Italy
| | - Giorgio J. Moro
- Dipartimento di Scienze Chimiche, Università di Padova, via Marzolo 1, 35131 Padova, Italy
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Malyar IV, Titov E, Lomadze N, Saalfrank P, Santer S. Photoswitching of azobenzene-containing self-assembled monolayers as a tool for control over silicon surface electronic properties. J Chem Phys 2017; 146:104703. [DOI: 10.1063/1.4978225] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Ivan V. Malyar
- Department of Nano- and Biomedical Technologies, Saratov State University, Astrakhanskaya 83, 410012 Saratov, Russia
| | - Evgenii Titov
- Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
- Theoretical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Nino Lomadze
- Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Peter Saalfrank
- Theoretical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Svetlana Santer
- Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
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Cantatore V, Granucci G, Rousseau G, Padula G, Persico M. Photoisomerization of Self-Assembled Monolayers of Azobiphenyls: Simulations Highlight the Role of Packing and Defects. J Phys Chem Lett 2016; 7:4027-4031. [PMID: 27669082 DOI: 10.1021/acs.jpclett.6b02018] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present surface hopping simulations of the photodynamics of self-assembled monolayers (SAMs) of 4'-(biphenyl-4-ylazo)-biphenyl-4-thiol (ABPT) on Au(111). We show that trans → cis photoisomerization is suppressed because of steric hindrance in a well-ordered SAM. Photoisomerization is instead viable in the presence of defects. Two particularly important defects are the boundaries between domains of trans-ABPT molecules leaning in different directions (a line defect) and single cis molecules embedded in a SAM of trans (a point defect). Our findings explain the cooperative behavior observed during the photoisomerization of a trans-ABPT SAM, leading to large domains of pure cis and trans isomers. The line and point defects are predicted to produce different patterns of cis-ABPT molecules during the early stages of the photoconversion.
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Affiliation(s)
- Valentina Cantatore
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa , v. G. Moruzzi 13, I-56124 Pisa, Italy
| | - Giovanni Granucci
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa , v. G. Moruzzi 13, I-56124 Pisa, Italy
| | - Guillaume Rousseau
- Magistère 2 de Physique Fondamentale, Université de Paris Sud 11 , Orsay 91400, France
| | - Giancarlo Padula
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa , v. G. Moruzzi 13, I-56124 Pisa, Italy
| | - Maurizio Persico
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa , v. G. Moruzzi 13, I-56124 Pisa, Italy
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