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Dang T, Zhang ZY, Li T. Visible-Light-Activated Heteroaryl Azoswitches: Toward a More Colorful Future. J Am Chem Soc 2024; 146:19609-19620. [PMID: 38991225 DOI: 10.1021/jacs.4c03135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024]
Abstract
Azobenzenes (Ph-N═N-Ph) are known as the most widely studied molecular photoswitches, and the recent rise of azoheteroarenes (Het-N═N-Ph or Het-N═N-Het) offers great opportunities to advance this already mature field. A common limitation is that azo-switches generally require harmful UV light for activation, which hinders their application across various fields. Despite great efforts in developing visible-light azobenzenes over the past few decades, the potential of visible-light heteroaryl azoswitches remains largely unexplored. This Perspective summarizes the state-of-the-art advancements in visible-light heteroaryl azoswitches, covering molecular design strategies, the structure-property relationship, and potential applications. We highlight the distinctive advantages of azoheteroarenes over azobenzenes in the research and development of visible-light switches. Furthermore, we discuss the opportunities and challenges in this emerging field and propose potential solutions to address crucial issues such as spectral red-shift and thermal half-life. Through this Perspective paper, we aim to provide inspiration for further exploration in this field, in anticipation of the growing prosperity and bright future of visible-light azoheteroarene photoswitches.
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Affiliation(s)
- Tongtong Dang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhao-Yang Zhang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tao Li
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
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2
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Kumar Gaur A, Gupta D, Narayanan Nampoothiry D, Velloth A, Kaur R, Kaur N, Venkataramani S. Azopyridinium Ionic Photoswitches: Tuning Half-Lives of Z Isomers from Seconds to Days in Water. Chemistry 2024:e202401239. [PMID: 38818941 DOI: 10.1002/chem.202401239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/24/2024] [Accepted: 05/30/2024] [Indexed: 06/01/2024]
Abstract
Herein, we describe water-soluble heteroaryl azopyridinium ionic photoswitches (HAPIPs). We aim to combine variations in five-membered heterocycles, their substitutions, N-alkyl groups at pyridinium nitrogen, the position of pyridinium center relative to azo group, counterions, and solvents, in achieving better photoswitching. Through these studies, we successfully tuned the half-life of Z isomers of the resultant HAPIPs between seconds to days in water. Extensive spectroscopic studies and density functional theory (DFT) computations unravelled the factors responsible for thermal relaxation behavior. Considering the versatility of these photoswitches, the tunability of half-lives and photoswitching in aqueous medium allows the scope of applications in several fields.
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Affiliation(s)
- Ankit Kumar Gaur
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, 140306, Punjab, India
| | - Debapriya Gupta
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, 140306, Punjab, India
| | - Dhanyaj Narayanan Nampoothiry
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, 140306, Punjab, India
| | - Archana Velloth
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, 140306, Punjab, India
| | - Ramanpreet Kaur
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, 140306, Punjab, India
| | - Navneet Kaur
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, 140306, Punjab, India
| | - Sugumar Venkataramani
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, 140306, Punjab, India
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3
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Fink M, Stäuble J, Weisgerber M, Carreira EM. Aryl Azocyclopropeniums: Minimalist, Visible-Light Photoswitches. J Am Chem Soc 2024; 146:9519-9525. [PMID: 38547006 PMCID: PMC11010232 DOI: 10.1021/jacs.4c01786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 03/07/2024] [Accepted: 03/11/2024] [Indexed: 04/11/2024]
Abstract
We report convenient syntheses of aryl azocyclopropeniums and a study of their photochemical properties. Incorporation of the smallest arene leads to pronounced redshift of the π-π* absorbance band, compared to azobenzenes. Photoisomerization under purple or green light irradiation affords Z- or E-isomers in ratios up to 94% Z or 90% E, and the switches proved stable over multiple irradiation cycles. Thermal half-lives of metastable Z-isomers range from minutes to hours in acetonitrile and water. These properties together with the concise, versatile syntheses render aryl azocyclopropeniums exciting additions to the tool kit of readily available molecular photoswitches for wide ranging applications.
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Affiliation(s)
- Moritz Fink
- Department of Chemistry and
Applied Biosciences, Laboratory of Organic Chemistry, ETH Zürich, 8093 Zürich, Switzerland
| | - Jannik Stäuble
- Department of Chemistry and
Applied Biosciences, Laboratory of Organic Chemistry, ETH Zürich, 8093 Zürich, Switzerland
| | - Maïté Weisgerber
- Department of Chemistry and
Applied Biosciences, Laboratory of Organic Chemistry, ETH Zürich, 8093 Zürich, Switzerland
| | - Erick M. Carreira
- Department of Chemistry and
Applied Biosciences, Laboratory of Organic Chemistry, ETH Zürich, 8093 Zürich, Switzerland
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4
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Reichenauer T, Böckmann M, Ziegler K, Kumar V, Ravoo BJ, Doltsinis NL, Schlücker S. Photoswitching of arylazopyrazoles upon S 1 (nπ*) excitation studied by transient absorption spectroscopy and ab initio molecular dynamics. Phys Chem Chem Phys 2024; 26:10832-10840. [PMID: 38525498 DOI: 10.1039/d4cp00295d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
Arylazopyrazoles (AAPs) are an important class of molecular photoswitches with high photostationary states (PSS) and long thermal lifetimes. The ultrafast photoisomerization of four water-soluble arylazopyrazoles, all of them featuring an ortho-dimethylated pyrazole ring, is studied by narrowband femtosecond transient absorption spectroscopy and ab initio molecular dynamics simulations. Upon S1 (nπ*) photoexcitation of the planar E-isomers (E-AAPs), excited-state bi-exponential decays with time constants τ1 in the 220-440 fs range and τ2 in the 1.4-1.8 ps range are observed, comparable to those reported for azobenzene (AB). This is indicative of the same photoisomerization mechanism as has been reported for ABs. In contrast to the planar E-AAPs, a twisted E-AAP with two methyl groups in ortho-position of the phenyl ring displays faster initial photoswitching with τ1 = 170 ± 10 fs and τ2 = 1.6 ± 0.1 ps. Our static DFT calculations and ab initio molecular dynamics simulations of E-AAPs on the S0 and S1 potential energy surfaces suggest that twisted E-isomer azo photoswitches exhibit faster initial photoisomerization dynamics out of the Franck-Condon region due to a weaker π-coordination of the central CNNC unit to the aromatic ligands.
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Affiliation(s)
- Till Reichenauer
- Physical Chemistry I and Center for Nanointegration Duisburg-Essen (CENIDE), Universität Duisburg-Essen, 45141 Essen, Germany
| | - Marcus Böckmann
- Institute of Solid-State Theory and Center for Multiscale Theory and Computation, Universität Münster, 48149 Münster, Germany.
| | - Katharina Ziegler
- Organic Chemistry Institute and Center for Soft Nanoscience (SoN), Universität Münster, 48148 Münster, Germany.
| | - Vikas Kumar
- Physical Chemistry I and Center for Nanointegration Duisburg-Essen (CENIDE), Universität Duisburg-Essen, 45141 Essen, Germany
| | - Bart Jan Ravoo
- Organic Chemistry Institute and Center for Soft Nanoscience (SoN), Universität Münster, 48148 Münster, Germany.
| | - Nikos L Doltsinis
- Institute of Solid-State Theory and Center for Multiscale Theory and Computation, Universität Münster, 48149 Münster, Germany.
| | - Sebastian Schlücker
- Physical Chemistry I and Center for Nanointegration Duisburg-Essen (CENIDE), Universität Duisburg-Essen, 45141 Essen, Germany
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5
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Steinmüller SAM, Odaybat M, Galli G, Prischich D, Fuchter MJ, Decker M. Arylazobenzimidazoles: versatile visible-light photoswitches with tuneable Z-isomer stability. Chem Sci 2024; 15:5360-5367. [PMID: 38577348 PMCID: PMC10988581 DOI: 10.1039/d3sc05246j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 02/28/2024] [Indexed: 04/06/2024] Open
Abstract
Benzimidazole heterocycles are of great importance in medicinal chemistry due to their applicability to a wide range of pharmacological targets, therefore representing a prototypical "privileged structure". In photopharmacology, azoheteroarene photoswitches have emerged as valuable tools for a variety of applications due to the high tuneability of their photophysical properties. Benzimidazole-based photoswitches could therefore enable the optically-controlled investigation of many pharmacological targets and find application in materials science. Here we report a combined experimental and computational investigation of such arylazobenzimidazoles, which allowed us to identify derivatives with near-quantitative bidirectional photoswitching using visible light and highly tuneable Z-isomer stability. We further demonstrate that arylazobenzimidazoles bearing a free benzimidazole N-H group not only exhibit efficient bidirectional photoswitching, but also excellent thermal Z-isomer stability, contrary to previously reported fast-relaxing Z-isomers of N-H azoheteroarenes. Finally, we describe derivatives which can be reversibly isomerized with cyan and red light, thereby enabling significantly "red-shifted" photocontrol over prior azoheteroarenes. The understanding gained in this study should enable future photopharmacological efforts by employing photoswitches based on the privileged benzimidazole structure.
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Affiliation(s)
- Sophie A M Steinmüller
- Pharmazeutische und Medizinische Chemie, Institut für Pharmazie und Lebensmittelchemie, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Magdalena Odaybat
- Department of Chemistry, Molecular Sciences Research Hub, White City Campus, Imperial College London London W12 0BZ UK
| | - Giulia Galli
- Pharmazeutische und Medizinische Chemie, Institut für Pharmazie und Lebensmittelchemie, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Davia Prischich
- Department of Chemistry, Molecular Sciences Research Hub, White City Campus, Imperial College London London W12 0BZ UK
| | - Matthew J Fuchter
- Department of Chemistry, Molecular Sciences Research Hub, White City Campus, Imperial College London London W12 0BZ UK
| | - Michael Decker
- Pharmazeutische und Medizinische Chemie, Institut für Pharmazie und Lebensmittelchemie, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
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6
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Hashim PK, Sahu S, Takahashi K, Thazhathethil S, Nakamura T, Tamaoki N. Geometry-Induced Oligomerization of Fluorine-Substituted Phenylazothiazole Photoswitches. Chemistry 2024; 30:e202400047. [PMID: 38278760 DOI: 10.1002/chem.202400047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 01/26/2024] [Accepted: 01/26/2024] [Indexed: 01/28/2024]
Abstract
Photoswitches are molecules that can absorb light of specific wavelengths and undergo a reversible transformation between their trans and cis isomeric forms. In phenylazo photoswitches, it is common for the less stable cis (Z) isomer to convert back to the more stable trans (E) isomer either through photochemical or thermal means. In this research, we designed new derivatives of phenylazothiazole (PAT) photoswitches, PAT-Fn, which feature fluorine substituents on their phenyl component. These derivatives can reversibly isomerize under visible light exposure with the enrichment of E and Z isomers at photostationary state (PSS). Surprisingly, we observed an unconventional phenomenon when these PAT-Fn (n≧2) photoswitches were in their cis isomeric state in the absence of light. Instead of the anticipated transformation from cis to trans isomer, these compounds converted to an oligomeric compound. Our detailed experimental investigation and theoretical calculations, indicated the crucial role of fluorine substituents and the distinctive geometric arrangement of the cis isomer in driving the unexpected oligomerization process originating from the cis isomeric state.
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Affiliation(s)
- P K Hashim
- Research Institute for Electronic Science, Hokkaido University, Kita 20, Nishi 10, Kita-ku, Sapporo, Hokkaido, 001-0020, Japan
- Graduate School of Life Science, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan
| | - Saugata Sahu
- Research Institute for Electronic Science, Hokkaido University, Kita 20, Nishi 10, Kita-ku, Sapporo, Hokkaido, 001-0020, Japan
| | - Kiyonori Takahashi
- Research Institute for Electronic Science, Hokkaido University, Kita 20, Nishi 10, Kita-ku, Sapporo, Hokkaido, 001-0020, Japan
- Graduate School of Environmental Science, Hokkaido University, Kita 10, Nishi 5, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan
| | - Shakkeeb Thazhathethil
- Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - Takayoshi Nakamura
- Research Institute for Electronic Science, Hokkaido University, Kita 20, Nishi 10, Kita-ku, Sapporo, Hokkaido, 001-0020, Japan
- Graduate School of Environmental Science, Hokkaido University, Kita 10, Nishi 5, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan
| | - Nobuyuki Tamaoki
- Research Institute for Electronic Science, Hokkaido University, Kita 20, Nishi 10, Kita-ku, Sapporo, Hokkaido, 001-0020, Japan
- Graduate School of Life Science, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan
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7
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Wang X, Hu Z, Liang L, Wang Z, Wang Y, Li Y, Xiao B. Effect of S⋯π interactions on the charge transport properties of the DPP framework. Chem Commun (Camb) 2024; 60:815-818. [PMID: 38086738 DOI: 10.1039/d3cc04995g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
In this work, we designed and synthesized two similar π-conjugated molecules, N-alkyl (DPP-R) and N-aryl (DPP-B), to comparatively explore the S⋯π interactions using a scanning tunneling microscopy-based break junction (STM-BJ) technique. The conductance results of the STM-BJ experiments indicated that DPP-R has a 66% greater conductance (G) than DPP-B. Combined with molecular simulations, it was demonstrated that the presence of S⋯π interactions led to a certain degree of orbital overlap of the highest occupied molecular orbital (HOMO), and created a favorable channel for electron transport in the DPP-B junction.
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Affiliation(s)
- Xu Wang
- The State Key Laboratory of Refractories and Metallurgy, and Institute of Advanced Materials and Nanotechnology, Faculty of Materials, Wuhan University of Science and Technology, Wuhan 430081, China.
| | - Zhonghao Hu
- The State Key Laboratory of Refractories and Metallurgy, and Institute of Advanced Materials and Nanotechnology, Faculty of Materials, Wuhan University of Science and Technology, Wuhan 430081, China.
| | - Lei Liang
- The State Key Laboratory of Refractories and Metallurgy, and Institute of Advanced Materials and Nanotechnology, Faculty of Materials, Wuhan University of Science and Technology, Wuhan 430081, China.
| | - Zhiye Wang
- The State Key Laboratory of Refractories and Metallurgy, and Institute of Advanced Materials and Nanotechnology, Faculty of Materials, Wuhan University of Science and Technology, Wuhan 430081, China.
| | - Yanze Wang
- The State Key Laboratory of Refractories and Metallurgy, and Institute of Advanced Materials and Nanotechnology, Faculty of Materials, Wuhan University of Science and Technology, Wuhan 430081, China.
| | - Yunchuan Li
- The State Key Laboratory of Refractories and Metallurgy, and Institute of Advanced Materials and Nanotechnology, Faculty of Materials, Wuhan University of Science and Technology, Wuhan 430081, China.
| | - Bohuai Xiao
- The State Key Laboratory of Refractories and Metallurgy, and Institute of Advanced Materials and Nanotechnology, Faculty of Materials, Wuhan University of Science and Technology, Wuhan 430081, China.
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8
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Sun W, Shangguan Z, Zhang X, Dang T, Zhang ZY, Li T. Solar Efficiency of Azo-Photoswitches for Energy Conversion: A Comprehensive Assessment. CHEMSUSCHEM 2023; 16:e202300582. [PMID: 37278140 DOI: 10.1002/cssc.202300582] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/28/2023] [Accepted: 06/05/2023] [Indexed: 06/07/2023]
Abstract
Photoswitches can absorb solar photons and store them as chemical energy by photoisomerization, which is regarded as a promising strategy for photochemical solar energy storage. Although many efforts have been devoted to photoswitch discovery, the solar efficiency, a critical fundamental parameter assessing the solar energy conversion ability, has attracted little attention and remains to be studied comprehensively. Here we provide a systematic evaluation of the solar efficiency of typical azo-switches including azobenzenes and azopyrazoles, and gain a comprehensive understanding on its decisive factors. All the efficiencies are found below 1.0 %, far from the proposed limits for molecular solar thermal energy storage systems. Azopyrazoles exhibit remarkably higher solar efficiencies (0.59-0.94 %) than azobenzenes (0.11-0.43 %), benefiting from largely improved quantum yield and photoisomerization yield. Light filters can be used to improve the isomerization yield but inevitably narrow the usable range of solar spectrum, and these two contradictory effects ultimately reduce solar efficiencies. We envision this conflict could be resolved through developing azo-switches that afford high isomerization yields by absorbing wide-spectrum solar energy. We hope this work could promote more efforts to improve the solar efficiency of photoswitches, which is highly relevant to the prospect for future applications.
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Affiliation(s)
- Wenjin Sun
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, P.R. China
| | - Zhichun Shangguan
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, P.R. China
| | - Xu Zhang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, P.R. China
| | - Tongtong Dang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, P.R. China
| | - Zhao-Yang Zhang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, P.R. China
| | - Tao Li
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, P.R. China
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9
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Adrion DM, Lopez SA. Design rules for optimization of photophysical and kinetic properties of azoarene photoswitches. Org Biomol Chem 2023; 21:7351-7357. [PMID: 37646103 DOI: 10.1039/d3ob01298k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Azoarenes are an important class of molecular photoswitches that often undergo E → Z isomerization with ultraviolet light and have short Z-isomer lifetimes. Azobenzene has been a widely studied photoswitch for decades but can be poorly suited for photopharmacological applications due to its UV-light absorption and short-lived Z-isomer half-life (t1/2). Recently, diazo photoswitches with one or more thiophene rings in place of a phenyl ring have emerged as promising candidates, as they exhibit a stable photostationary state (98% E → Z conversion) and E-isomer absorption (λmax) in the visible light range (405 nm). In this work, we performed density functional theory calculations [PBE0-D3BJ/6-31+G(d,p)] on 26 hemi-azothiophenes, substituted with one phenyl ring and one thiophene ring on the diazo bond. We calculated the E-isomer absorption (λmax) and Z-isomer t1/2 for a set of 26 hemi-azothiophenes. We compared their properties to thiophene-based photoswitches that have been studied previously. We separated the 26 proposed photoswitches into four quadrants based on their λmax and t1/2 relative to past generations of hemi-azothiophene photoswitches. We note 8 hemi-azothiophenes with redshifted λmax and longer t1/2 than previous systems. Our top candidate has λmax and a t1/2 approaching 360 nm and 279 years, respectively. The results here present a pathway towards leveraging and optimizing two properties of photoswitches previously thought to be inversely related.
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Affiliation(s)
- Daniel M Adrion
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts, 02115, USA.
| | - Steven A Lopez
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts, 02115, USA.
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10
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Dolai A, Box SM, Bhunia S, Bera S, Das A, Samanta S. Photoisomerization of 2-Arylazoimidazoles under Visible Light: Identifying a Predictive Tool to Anticipate and Tune Likely Photoswitching Performance and Cis Half-Life. J Org Chem 2023. [PMID: 37368413 DOI: 10.1021/acs.joc.3c00211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Azopyrazoles are an emerging class of photoswitches, whereas analogous azoimidazole-based switches are unable to draw much attention because of their short cis half-lives, poor cis-trans photoreversion yields, and toxic ultraviolet (UV) light-assisted isomerization. A series of 24 various aryl-substituted N-methyl-2-arylazoimidazoles were synthesized, and their photoswitching performances and cis-trans isomerization kinetics were thoroughly investigated experimentally and theoretically. Para-π-donor-substituted azoimidazoles with highly twisted T-shaped cis conformations showed nearly complete bidirectional photoswitching, whereas di-o-substituted switches exhibited very long cis half-lives (days-years) with nearly ideal T-shaped conformations. This study demonstrates how the electron density in the aryl ring affects cis half-life and cis-trans photoreversion via twisting of the NNAr dihedral angle that can be used as a predictive metric for envisaging and tuning the likely switching performance and half-life of any given 2-arylazoimidazole. By applying this tool, two better-performing azoimidazole photoswitches were engineered. All switches permitted irradiation by violet (400-405 nm) and orange (>585 nm) light for forward and reverse isomerization, respectively, and displayed comparatively high quantum yields and impressive resistance to photobleaching.
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Affiliation(s)
- Anirban Dolai
- Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009, West Bengal, India
| | - Sk Majid Box
- Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009, West Bengal, India
| | - Supriya Bhunia
- Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009, West Bengal, India
| | - Satyajit Bera
- Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009, West Bengal, India
| | - Arpan Das
- Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009, West Bengal, India
| | - Subhas Samanta
- Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009, West Bengal, India
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11
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Gaur AK, Gupta D, Mahadevan A, Kumar P, Kumar H, Nampoothiry DN, Kaur N, Thakur SK, Singh S, Slanina T, Venkataramani S. Bistable Aryl Azopyrazolium Ionic Photoswitches in Water. J Am Chem Soc 2023; 145:10584-10594. [PMID: 37133353 DOI: 10.1021/jacs.2c13733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We report a new class of arylazopyrazolium-based ionic photoswitches (AAPIPs). These AAPIPs with different counter ions have been accessed through a modular synthetic approach in high yields. More importantly, the AAPIPs exhibit excellent reversible photoswitching and exceptional thermal stability in water. The effects of solvents, counter ions, substitutions, concentration, pH, and glutathione (GSH) have been evaluated using spectroscopic investigations. The results revealed that the bistability of studied AAPIPs is robust and near quantitative. The thermal half-life of Z isomers is extremely high in water (up to years), and it can be lowered electronically by the electron-withdrawing groups or highly basic pH.
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Affiliation(s)
- Ankit Kumar Gaur
- Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, Punjab 140 306, India
| | - Debapriya Gupta
- Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, Punjab 140 306, India
| | - Anjali Mahadevan
- Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, Punjab 140 306, India
| | - Pravesh Kumar
- Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, Punjab 140 306, India
| | - Himanshu Kumar
- Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, Punjab 140 306, India
| | - Dhanyaj Narayanan Nampoothiry
- Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, Punjab 140 306, India
| | - Navneet Kaur
- Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, Punjab 140 306, India
| | - Sandeep Kumar Thakur
- Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, Punjab 140 306, India
| | - Sanjay Singh
- Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, Punjab 140 306, India
| | - Tomáš Slanina
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo náměstí 542, Prague 6, Prague 160 00, Czech Republic
| | - Sugumar Venkataramani
- Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli, Punjab 140 306, India
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12
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Franz E, Jung J, Kunz A, Wegner HA, Brummel O, Mollenhauer D, Libuda J. How Adsorption Affects the Energy Release in an Azothiophene-Based Molecular Solar-Thermal System. J Phys Chem Lett 2023; 14:1470-1477. [PMID: 36744855 DOI: 10.1021/acs.jpclett.2c03732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Molecular solar-thermal (MOST) systems combine solar energy conversion, storage, and release within one single molecule. To release the energy, different approaches are applicable, e.g., the electrochemical and the catalytic pathways. While the electrochemical pathway requires catalytically inert electrode materials, the catalytic pathway requires active and selective catalysts. In this work, we studied the catalytic activity and selectivity of graphite(0001), Pt(111), and Au(111) surfaces for the energy release from the MOST system 3-cyanophenylazothiophene along with its adsorption properties. In our study, we combine in situ photochemical IR spectroscopy and density functional theory (DFT). Graphite(0001) is catalytically inactive, shows the weakest reactant-surface interaction, and therefore is ideally suitable for electrochemical triggering. On Pt(111), we observe strong reactant-surface interactions along with moderate catalytic activity and partial decomposition, which limit the applicability of this material. On Au(111), we observe high catalytic activity and high selectivity (>99%). We assign these catalytic properties to the moderate reactant surface interaction, which prevents decomposition but facilitates energy release via a singlet-triplet mechanism.
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Affiliation(s)
- Evanie Franz
- Interface Research and Catalysis, Erlangen Center for Interface Research and Catalysis, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058Erlangen, Germany
| | - Jannis Jung
- Institute of Physical Chemistry, Justus Liebig University Giessen, DE-35392Giessen, Germany
- Center for Materials Research (ZfM), Justus Liebig University Giessen, DE-35392Giessen, Germany
| | - Anne Kunz
- Center for Materials Research (ZfM), Justus Liebig University Giessen, DE-35392Giessen, Germany
- Institute of Organic Chemistry, Justus Liebig University, Heinrich-Buff-Ring 17, 35392Giessen, Germany
| | - Hermann A Wegner
- Center for Materials Research (ZfM), Justus Liebig University Giessen, DE-35392Giessen, Germany
- Institute of Organic Chemistry, Justus Liebig University, Heinrich-Buff-Ring 17, 35392Giessen, Germany
| | - Olaf Brummel
- Interface Research and Catalysis, Erlangen Center for Interface Research and Catalysis, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058Erlangen, Germany
| | - Doreen Mollenhauer
- Institute of Physical Chemistry, Justus Liebig University Giessen, DE-35392Giessen, Germany
- Center for Materials Research (ZfM), Justus Liebig University Giessen, DE-35392Giessen, Germany
| | - Jörg Libuda
- Interface Research and Catalysis, Erlangen Center for Interface Research and Catalysis, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058Erlangen, Germany
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13
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Franz E, Kunz A, Oberhof N, Heindl AH, Bertram M, Fusek L, Taccardi N, Wasserscheid P, Dreuw A, Wegner HA, Brummel O, Libuda J. Electrochemically Triggered Energy Release from an Azothiophene-Based Molecular Solar Thermal System. CHEMSUSCHEM 2022; 15:e202200958. [PMID: 35762102 PMCID: PMC9796447 DOI: 10.1002/cssc.202200958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/23/2022] [Indexed: 05/09/2023]
Abstract
Molecular solar thermal (MOST) systems combine solar energy conversion, storage, and release in simple one-photon one-molecule processes. Here, we address the electrochemically triggered energy release from an azothiophene-based MOST system by photoelectrochemical infrared reflection absorption spectroscopy (PEC-IRRAS) and density functional theory (DFT). Specifically, the electrochemically triggered back-reaction from the energy rich (Z)-3-cyanophenylazothiophene to its energy lean (E)-isomer using highly oriented pyrolytic graphite (HOPG) as the working electrode was studied. Theory predicts that two reaction channels are accessible, an oxidative one (hole-catalyzed) and a reductive one (electron-catalyzed). Experimentally it was found that the photo-isomer decomposes during hole-catalyzed energy release. Electrochemically triggered back-conversion was possible, however, through the electron-catalyzed reaction channel. The reaction rate could be tuned by the electrode potential within two orders of magnitude. It was shown that the MOST system withstands 100 conversion cycles without detectable decomposition of the photoswitch. After 100 cycles, the photochemical conversion was still quantitative and the electrochemically triggered back-reaction reached 94 % of the original conversion level.
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Affiliation(s)
- Evanie Franz
- Interface Research and CatalysisErlangen Center for Interface Research and CatalysisFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
| | - Anne Kunz
- Institute of Organic ChemistryJustus-Liebig-UniversitätHeinrich-Buff-Ring 1735392GiessenGermany
| | - Nils Oberhof
- Interdisciplinary Center for Scientific ComputingUniversität HeidelbergIm Neuenheimer Feld 205 A69120HeidelbergGermany
| | - Andreas H. Heindl
- Institute of Organic ChemistryJustus-Liebig-UniversitätHeinrich-Buff-Ring 1735392GiessenGermany
| | - Manon Bertram
- Interface Research and CatalysisErlangen Center for Interface Research and CatalysisFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
| | - Lukas Fusek
- Interface Research and CatalysisErlangen Center for Interface Research and CatalysisFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
| | - Nicola Taccardi
- Institute of Chemical Reaction EngineeringFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 3D-91058ErlangenGermany
| | - Peter Wasserscheid
- Institute of Chemical Reaction EngineeringFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 3D-91058ErlangenGermany
- Forschungszentrum Jülich GmbHHelmholtz Institute Erlangen-Nürnberg for Renewable EnergyEgerlandstraße 3D-91058ErlangenGermany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific ComputingUniversität HeidelbergIm Neuenheimer Feld 205 A69120HeidelbergGermany
| | - Hermann A. Wegner
- Institute of Organic ChemistryJustus-Liebig-UniversitätHeinrich-Buff-Ring 1735392GiessenGermany
| | - Olaf Brummel
- Interface Research and CatalysisErlangen Center for Interface Research and CatalysisFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
| | - Jörg Libuda
- Interface Research and CatalysisErlangen Center for Interface Research and CatalysisFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
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14
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Gaur AK, Kumar H, Gupta D, Tom IP, Nampoothiry DN, Thakur SK, Mahadevan A, Singh S, Venkataramani S. Structure-Property Relationship for Visible Light Bidirectional Photoswitchable Azoheteroarenes and Thermal Stability of Z-Isomers. J Org Chem 2022; 87:6541-6551. [PMID: 35486716 DOI: 10.1021/acs.joc.2c00088] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A modular approach has been adopted to synthesize a wide range of visible light-driven photoswitchable azoheteroarenes. In this regard, we considered ortho substitution of cyclic amines in the aryl ring and varied substitution patterns. Using detailed spectroscopic studies, we established a relationship between structure and photoswitching ability and also half-lives of the Z-isomers. Through this, we envision tunable and bidirectional longer wavelength photoswitches.
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Affiliation(s)
- Ankit Kumar Gaur
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli 140306, Punjab, India
| | - Himanshu Kumar
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli 140306, Punjab, India
| | - Debapriya Gupta
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli 140306, Punjab, India
| | - Irin Pottanani Tom
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli 140306, Punjab, India
| | - Dhanyaj Narayanan Nampoothiry
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli 140306, Punjab, India
| | - Sandeep Kumar Thakur
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli 140306, Punjab, India
| | - Anjali Mahadevan
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli 140306, Punjab, India
| | - Sanjay Singh
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli 140306, Punjab, India
| | - Sugumar Venkataramani
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Knowledge City, Manauli 140306, Punjab, India
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15
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He F, Ren X, Jiang J, Zhang G, He L. Real-Time, Time-Dependent Density Functional Theory Study on Photoinduced Isomerizations of Azobenzene Under a Light Field. J Phys Chem Lett 2022; 13:427-432. [PMID: 34989580 DOI: 10.1021/acs.jpclett.1c03442] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The trans to cis photoisomerization of azobenzene and its reverse (i.e., the cis to trans) processes are studied using real-time propagation time-dependent density functional theory combined with molecular dynamics for ions. We show that the wavelength of the applied laser may significantly affect the transition process. The simulations also show that the photon-excited electrons play essential roles in the isomerization processes, in which the hot electrons couple to phonon modes that drive the transitions.
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Affiliation(s)
- Fuxiang He
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xinguo Ren
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jun Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Nanoscience, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guozhen Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Nanoscience, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Lixin He
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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16
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Adrion DM, Lopez SA. Cross-conjugation controls the stabilities and photophysical properties of heteroazoarene photoswitches. Org Biomol Chem 2022; 20:5989-5998. [PMID: 35014651 DOI: 10.1039/d1ob02026a] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Azoarene photoswitches are versatile molecules that interconvert from their E-isomer to their Z-isomer with light. Azobenzene is a prototypical photoswitch but its derivatives can be poorly suited for in vivo applications such as photopharmacology due to undesired photochemical reactions promoted by ultraviolet light and the relatively short half-life (t1/2) of the Z-isomer (2 days). Experimental and computational studies suggest that these properties (λmax of the E isomer and t1/2 of the Z-isomer) are inversely related. We identified isomeric azobisthiophenes and azobisfurans from a high-throughput screening study of 1540 azoarenes as photoswitch candidates with improved λmax and t1/2 values relative to azobenzene. We used density functional theory to predict the activation free energies and vertical excitation energies of the E- and Z-isomers of 2,2- and 3,3-substituted azobisthiophenes and azobisfurans. The half-lives depend on whether the heterocycles are π-conjugated or cross-conjugated with the diazo π-bond. The 2,2-substituted azoarenes both have t1/2 values on the scale of 1 hour, while the 3,3-analogues have computed half-lives of 40 and 230 years (thiophene and furan, respectively). The 2,2-substituted heteroazoarenes have significantly higher λmax absorptions than their 3,3-substituted analogues: 76 nm for azofuran and 77 nm for azothiophene.
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Affiliation(s)
- Daniel M Adrion
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts, 02115, USA.
| | - Steven A Lopez
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts, 02115, USA.
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17
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Sah C, Mahadevan A, Kumar P, Venkataramani S. The curious case of the photochemistry of 2-hydroxyphenylazo-3,5-dimethylisoxazole: Unravelling the process among tautomer-ization, photoisomerization, and conformational changes. Phys Chem Chem Phys 2022; 24:7848-7855. [DOI: 10.1039/d1cp05344b] [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
Photoswitching in azo compounds is well established. Typically, the planar trans molecule (native) can undergo isomerization to cis isomer and vice versa in solution by light. However, observing such photochemistry...
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18
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Mazumder A, Sebastian E, Hariharan M. Solvent dielectric delimited nitro–nitrito photorearrangement in a perylenediimide derivative. Chem Sci 2022; 13:8860-8870. [PMID: 35975155 PMCID: PMC9350666 DOI: 10.1039/d2sc02979k] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 07/04/2022] [Indexed: 12/04/2022] Open
Abstract
The discovery of vibrant excited-state dynamics and distinctive photochemistry has established nitrated polycyclic aromatic hydrocarbons as an exhilarating class of organic compounds. Herein, we report the atypical photorearrangement of nitro-perylenediimide (NO2-PDI) to nitrito-perylenediimide (ONO-PDI), triggered by visible-light excitation and giving rise to linkage isomers in the polar aprotic solvent acetonitrile. ONO-PDI has been isolated and unambiguously characterized using standard spectroscopic, spectrometric, and elemental composition techniques. Although nitritoaromatic compounds are conventionally considered to be crucial intermediates in the photodissociation of nitroaromatics, experimental evidence for this has not been observed heretofore. Ultrafast transient absorption spectroscopy combined with computational investigations revealed the prominence of a conformationally relaxed singlet excited-state (SCR1) of NO2-PDI in the photoisomerization pathway. Theoretical transition state (TS) analysis indicated the presence of a six-membered cyclic TS, which is pivotal in connecting the SCR1 state to the photoproduct state. This article addresses prevailing knowledge gaps in the field of organic linkage isomers and provides a comprehensive understanding of the unprecedented photoisomerization mechanism operating in the case of NO2-PDI. The unprecedented photorearrangement of nitro-perylenediimide (NO2-PDI) to nitrito-perylenediimide (ONO-PDI) is shown to occur through a cyclic six-membered transition state triggered by visible-light excitation.![]()
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Affiliation(s)
- Aniruddha Mazumder
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala, India 695551
| | - Ebin Sebastian
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala, India 695551
| | - Mahesh Hariharan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala, India 695551
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19
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Wortmann S, Schloeglmann S, Nuernberger P. Sensitivity of Isomerization Kinetics of 1,3,5-Triphenylformazan on Cosolvents Added to Toluene. J Org Chem 2021; 87:1745-1755. [PMID: 34843237 DOI: 10.1021/acs.joc.1c01928] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Formazan molecules exhibit photochromism because isomerization processes following excitation may occur in both the azo group and the hydrazone group; thus, each formazan may be present in various forms with different colors. The ratio of these forms depends on the illumination conditions and the environment of the formazan with a most incisive sensibility of the thermal anti-syn relaxation of the C═N toward slight traces of impurities in toluene solutions, as reported most prominently for 1,3,5-triphenylformazan. Here, we study the latter compound with transient absorption spectroscopy to investigate the role of these traces by adding small amounts of both protic and aprotic cosolvents. Whereas the activation barrier decreases if the binary solvent mixture has a higher polarity, the role of hydrogen bonding can have a reverse impact on the thermal isomerization rate. Both the addition of an aprotic cosolvent and the addition of a protic cosolvent can slow the reaction due to their hydrogen-bond accepting and hydrogen-bond donating properties, respectively. In the case of methanol as a cosolvent, this effect outweighed that of the polarity increase for small concentrations, which was not observed for the fluorinated alcohol hexafluoroisopropanol. The results are explained in the context of a competition between solute-cosolvent and cosolvent-cosolvent hydrogen bonding.
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Affiliation(s)
- Svenja Wortmann
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany
| | - Sylvia Schloeglmann
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany
| | - Patrick Nuernberger
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany
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20
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Mukadum F, Nguyen Q, Adrion DM, Appleby G, Chen R, Dang H, Chang R, Garnett R, Lopez SA. Efficient Discovery of Visible Light-Activated Azoarene Photoswitches with Long Half-Lives Using Active Search. J Chem Inf Model 2021; 61:5524-5534. [PMID: 34752100 DOI: 10.1021/acs.jcim.1c00954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Photoswitches are molecules that undergo a reversible, structural isomerization after exposure to certain wavelengths of light. The dynamic control offered by molecular photoswitches is favorable for materials chemistry, photopharmacology, and catalysis applications. Ideal photoswitches absorb visible light and have long-lived metastable isomers. We used high-throughput virtual screening to predict the absorption maxima (λmax) of the E-isomer and half-life (t1/2) of the Z-isomer. However, computing the photophysical and kinetic stabilities with density functional theory of each entry of a virtual molecular library containing thousands or millions of molecules is prohibitively time-consuming. We applied active search, a machine-learning technique, to intelligently search a chemical search space of 255 991 photoswitches based on 29 known azoarenes and their derivatives. We iteratively trained the active search algorithm on whether a candidate absorbed visible light (λmax > 450 nm). Active search was found to triple the discovery rate compared to random search. Further, we projected 1962 photoswitches to 2D using the Uniform Manifold Approximation and Projection algorithm and found that λmax depends on the core, which is tunable by substituents. We then incorporated a second stage of screening to predict the stabilities of the Z-isomers for the top candidates of each core. We identified four ideal photoswitches that concurrently satisfy the following criteria: λmax > 450 nm and t1/2 > 2 h.These candidates had λmax and t1/2 range from 465 to 531 nm and hours to days, respectively.
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Affiliation(s)
- Fatemah Mukadum
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Quan Nguyen
- Department of Computer Science and Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Daniel M Adrion
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Gabriel Appleby
- Department of Computer Science, Tufts University, Medford, Massachusetts 02155, United States
| | - Rui Chen
- Department of Computer Science, Tufts University, Medford, Massachusetts 02155, United States
| | - Haley Dang
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Remco Chang
- Department of Computer Science, Tufts University, Medford, Massachusetts 02155, United States
| | - Roman Garnett
- Department of Computer Science and Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Steven A Lopez
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
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21
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Volarić J, Szymanski W, Simeth NA, Feringa BL. Molecular photoswitches in aqueous environments. Chem Soc Rev 2021; 50:12377-12449. [PMID: 34590636 PMCID: PMC8591629 DOI: 10.1039/d0cs00547a] [Citation(s) in RCA: 129] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Indexed: 12/17/2022]
Abstract
Molecular photoswitches enable dynamic control of processes with high spatiotemporal precision, using light as external stimulus, and hence are ideal tools for different research areas spanning from chemical biology to smart materials. Photoswitches are typically organic molecules that feature extended aromatic systems to make them responsive to (visible) light. However, this renders them inherently lipophilic, while water-solubility is of crucial importance to apply photoswitchable organic molecules in biological systems, like in the rapidly emerging field of photopharmacology. Several strategies for solubilizing organic molecules in water are known, but there are not yet clear rules for applying them to photoswitchable molecules. Importantly, rendering photoswitches water-soluble has a serious impact on both their photophysical and biological properties, which must be taken into consideration when designing new systems. Altogether, these aspects pose considerable challenges for successfully applying molecular photoswitches in aqueous systems, and in particular in biologically relevant media. In this review, we focus on fully water-soluble photoswitches, such as those used in biological environments, in both in vitro and in vivo studies. We discuss the design principles and prospects for water-soluble photoswitches to inspire and enable their future applications.
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Affiliation(s)
- Jana Volarić
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, Faculty for Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Wiktor Szymanski
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, Faculty for Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
- Department of Radiology, Medical Imaging Center, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Nadja A Simeth
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, Faculty for Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
- Institute for Organic and Biomolecular Chemistry, University of Göttingen, Tammannstr. 2, 37077 Göttingen, Germany
| | - Ben L Feringa
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, Faculty for Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
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22
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Fang D, Zhang ZY, Shangguan Z, He Y, Yu C, Li T. (Hetero)arylazo-1,2,3-triazoles: "Clicked" Photoswitches for Versatile Functionalization and Electronic Decoupling. J Am Chem Soc 2021; 143:14502-14510. [PMID: 34476949 DOI: 10.1021/jacs.1c08704] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The development of light-responsive chemical systems often relies on the rational design and suitable incorporation of molecular photoswitches such as azobenzenes. Linking a photoswitch core with another π-conjugated molecular entity may give rise to intramolecular electronic coupling, which can dramatically impair the photoswitch function. Decoupling strategies have been developed based on additionally inserting a linker that can disrupt the through-bond electronic communication. Here we show that 1,2,3-triazole-a commonly used decoupling spacer-can be directly merged into the azoswitch core to construct a class of "self-decoupling" azoswitches called (hetero)arylazo-1,2,3-triazoles. Such azotriazole photoswitches are easily accessed and modularly functionalized by click chemistry. Their photoswitch property can be optimized by rational design of the substituent groups or heteroaryl rings, allowing (near-)quantitative E⇆Z photoisomerization yields and tunable Z-isomer thermal half-lives from days to years. Combined experimental and theoretical results demonstrate that the electronic structure of the photoswitch core is not substantially affected by various substituents attached to the 1,2,3-triazole unit, benefiting from its cross-conjugated nature. The combination of clickable synthesis, tunable photoswitch property, and self-decoupling ability makes (hetero)arylazo-1,2,3-triazoles intriguing molecular tools in developing photoresponsive systems with desired performance.
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Affiliation(s)
- Dong Fang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhao-Yang Zhang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhichun Shangguan
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yixin He
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chunyang Yu
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tao Li
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
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23
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Pfaff P, Anderl F, Fink M, Balkenhohl M, Carreira EM. Azoacetylenes for the Synthesis of Arylazotriazole Photoswitches. J Am Chem Soc 2021; 143:14495-14501. [PMID: 34478268 PMCID: PMC8447256 DOI: 10.1021/jacs.1c06014] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We report a modular approach toward novel arylazotriazole photoswitches and their photophysical characterization. Addition of lithiated TIPS-acetylene to aryldiazonium tetrafluoroborate salts gives a wide range of azoacetylenes, constituting an underexplored class of stable intermediates. In situ desilylation transiently leads to terminal arylazoacetylenes that undergo copper-catalyzed cycloadditions (CuAAC) with a diverse collection of organoazides. These include complex molecules derived from natural products or drugs, such as colchicine, taxol, tamiflu, and arachidonic acid. The arylazotriazoles display near-quantitative photoisomerization and long thermal Z-half-lives. Using the method, we introduce for the first time the design and synthesis of a diacetylene platform. It permits implementation of consecutive and diversity-oriented approaches linking two different conjugants to independently addressable acetylenes within a common photoswitchable azotriazole. This is showcased in the synthesis of several photoswitchable conjugates, with potential applications as photoPROTACs and biotin conjugates.
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24
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Adrion DM, Kaliakin DS, Neal P, Lopez SA. Benchmarking of Density Functionals for Z-Azoarene Half-Lives via Automated Transition State Search. J Phys Chem A 2021; 125:6474-6485. [PMID: 34260236 DOI: 10.1021/acs.jpca.1c01695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular photoswitches use light to interconvert from a thermodynamically stable isomer into a metastable isomer. Photoswitches have been used in photopharmacology, catalysis, and molecular solar thermal (MOST) materials because of their spatiotemporal activation. Visible-light-absorbing photoswitches are especially attractive because low-energy light minimizes undesired photochemical reactions and enables biological applications. Ideal photoswitches require well-separated absorption spectra for both isomers and long-lived metastable states. However, predicting thermal half-lives with density functional theory is difficult because it requires locating transition structures and chosing an accurate model chemistry. We now report EZ-TS; by automatically calculating activation energies for the thermal Z → E isomerization. We used 28 density functionals [local spin density approximation, generalized gradient approximation, meta-GGA, hybrid GGA, and hybrid meta-GGA] and five basis sets [6-31G(d), 6-31+G(d,p), 6-311+G(d,p), cc-pVDZ, and aug-cc-pVDZ]. The hybrid GGA functionals performed the best among all tested functionals. We demonstrate that the mean absolute errors of 14 model chemistries approach chemical accuracy.
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Affiliation(s)
- Daniel M Adrion
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Danil S Kaliakin
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Patrick Neal
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Steven A Lopez
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
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25
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He Y, Shangguan Z, Zhang Z, Xie M, Yu C, Li T. Azobispyrazole Family as Photoswitches Combining (Near‐) Quantitative Bidirectional Isomerization and Widely Tunable Thermal Half‐Lives from Hours to Years**. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103705] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yixin He
- School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules Shanghai Key Laboratory of Electrical Insulation and Thermal Aging Shanghai Jiao Tong University Shanghai 200240 China
| | - Zhichun Shangguan
- School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules Shanghai Key Laboratory of Electrical Insulation and Thermal Aging Shanghai Jiao Tong University Shanghai 200240 China
| | - Zhao‐Yang Zhang
- School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules Shanghai Key Laboratory of Electrical Insulation and Thermal Aging Shanghai Jiao Tong University Shanghai 200240 China
| | - Mingchen Xie
- School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules Shanghai Key Laboratory of Electrical Insulation and Thermal Aging Shanghai Jiao Tong University Shanghai 200240 China
| | - Chunyang Yu
- School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules Shanghai Key Laboratory of Electrical Insulation and Thermal Aging Shanghai Jiao Tong University Shanghai 200240 China
| | - Tao Li
- School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules Shanghai Key Laboratory of Electrical Insulation and Thermal Aging Shanghai Jiao Tong University Shanghai 200240 China
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26
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He Y, Shangguan Z, Zhang ZY, Xie M, Yu C, Li T. Azobispyrazole Family as Photoswitches Combining (Near-) Quantitative Bidirectional Isomerization and Widely Tunable Thermal Half-Lives from Hours to Years*. Angew Chem Int Ed Engl 2021; 60:16539-16546. [PMID: 33852166 DOI: 10.1002/anie.202103705] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/13/2021] [Indexed: 11/08/2022]
Abstract
Azobenzenes are classical molecular photoswitches that have been widely used. In recent endeavors of molecular design, replacing one or both phenyl rings with heteroaromatic rings has emerged as a strategy to expand molecular diversity and access improved photoswitching properties. Many mono-heteroaryl azo molecules with unique structures and/or properties have been developed, but the potential of bis-heteroaryl architectures is far from fully exploited. We report a family of azobispyrazoles, which combine (near-)quantitative bidirectional photoconversion and widely tunable Z-isomer thermal half-lives from hours to years. The two five-membered rings remarkably weaken the intramolecular steric hindrance, providing new possibilities for engineering the geometric and electronic structure of azo photoswitches. Azobispyrazoles generally exhibit twisted Z-isomers that facilitate complete Z→E photoisomerization, and their thermal stability can be broadly adjusted regardless of the twisted shape, overcoming the conflict between photoconversion (favored by the twisted shape) and Z-isomer stability (favored by the orthogonal shape) encountered by mono-heteroaryl azo switches.
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Affiliation(s)
- Yixin He
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhichun Shangguan
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhao-Yang Zhang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Mingchen Xie
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Chunyang Yu
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Tao Li
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
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27
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Heindl AH, Wegner HA. Rational Design of Azothiophenes-Substitution Effects on the Switching Properties. Chemistry 2020; 26:13730-13737. [PMID: 32330338 PMCID: PMC7702042 DOI: 10.1002/chem.202001148] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Indexed: 12/22/2022]
Abstract
A series of substituted azothiophenes was prepared and investigated toward their isomerization behavior. Compared to azobenzene (AB), the presented compounds showed red-shifted absorption and almost quantitative photoisomerization to their (Z) states. Furthermore, it was found that electron-withdrawing substitution on the phenyl moiety increases, while electron-donating substitution decreases the thermal half-lives of the (Z)-isomers due to higher or lower stabilization by a lone pair-π interaction. Additionally, computational analysis of the isomerization revealed that a pure singlet state transition state is unlikely in azothiophenes. A pathway via intersystem crossing to a triplet energy surface of lower energy than the singlet surface provided a better fit with experimental data of the (Z)→(E) isomerization. The insights gained in this study provide the necessary guidelines to design effective thiophenylazo-photoswitches for applications in photopharmacology, material sciences, or solar energy harvesting applications.
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Affiliation(s)
- Andreas H. Heindl
- Institute of Organic ChemistryJustus Liebig UniversityHeinrich-Buff-Ring 1735392GiessenGermany
- Center for Material Research (LaMa)Justus Liebig UniversityHeinrich-Buff-Ring 1635392GiessenGermany
| | - Hermann A. Wegner
- Institute of Organic ChemistryJustus Liebig UniversityHeinrich-Buff-Ring 1735392GiessenGermany
- Center for Material Research (LaMa)Justus Liebig UniversityHeinrich-Buff-Ring 1635392GiessenGermany
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28
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Čechová L, Filo J, Dračínský M, Slavov C, Sun D, Janeba Z, Slanina T, Wachtveitl J, Procházková E, Cigáň M. Polysubstituted 5‐Phenylazopyrimidines: Extremely Fast Non‐ionic Photochromic Oscillators. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202007065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Lucie Čechová
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo nám. 2 16610 Prague Czech Republic
| | - Juraj Filo
- Institute of Chemistry Comenius University Ilkovičova 6 84215 Bratislava Slovakia
| | - Martin Dračínský
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo nám. 2 16610 Prague Czech Republic
| | - Chavdar Slavov
- Institute of Physical and Theoretical Chemistry Goethe University Max-von-Laue Straße 7 60438 Frankfurt am Main Germany
| | - Dazhong Sun
- Institute of Physical and Theoretical Chemistry Goethe University Max-von-Laue Straße 7 60438 Frankfurt am Main Germany
| | - Zlatko Janeba
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo nám. 2 16610 Prague Czech Republic
| | - Tomáš Slanina
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo nám. 2 16610 Prague Czech Republic
| | - Josef Wachtveitl
- Institute of Physical and Theoretical Chemistry Goethe University Max-von-Laue Straße 7 60438 Frankfurt am Main Germany
| | - Eliška Procházková
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo nám. 2 16610 Prague Czech Republic
| | - Marek Cigáň
- Institute of Chemistry Comenius University Ilkovičova 6 84215 Bratislava Slovakia
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29
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Čechová L, Filo J, Dračínský M, Slavov C, Sun D, Janeba Z, Slanina T, Wachtveitl J, Procházková E, Cigáň M. Polysubstituted 5-Phenylazopyrimidines: Extremely Fast Non-ionic Photochromic Oscillators. Angew Chem Int Ed Engl 2020; 59:15590-15594. [PMID: 32433814 DOI: 10.1002/anie.202007065] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Indexed: 11/09/2022]
Abstract
Photochromic systems with an ultrahigh rate of thermal relaxation are highly desirable for the development of new efficient photochromic oscillators. Based on DFT calculations, we designed a series of 5-phenylazopyrimidines with strong push-pull character in silico and observed very low energy barriers for the thermal (Z)-to-(E) isomerization. The structure of the (Z)-isomer of the slowest isomerizing derivative in the series was confirmed by NMR analysis with in situ irradiation at low temperature. The substituents can tune the lifetime of thermal back isomerization from hundreds of microseconds to several nanoseconds (8 orders of magnitude). The photoswitching parameters were extracted from transient absorption techniques and a dominant rotation mechanism of the (Z)-to-(E) thermal fading was proposed based on DFT calculations.
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Affiliation(s)
- Lucie Čechová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague, Czech Republic
| | - Juraj Filo
- Institute of Chemistry, Comenius University, Ilkovičova 6, 84215, Bratislava, Slovakia
| | - Martin Dračínský
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague, Czech Republic
| | - Chavdar Slavov
- Institute of Physical and Theoretical Chemistry, Goethe University, Max-von-Laue Straße 7, 60438, Frankfurt am Main, Germany
| | - Dazhong Sun
- Institute of Physical and Theoretical Chemistry, Goethe University, Max-von-Laue Straße 7, 60438, Frankfurt am Main, Germany
| | - Zlatko Janeba
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague, Czech Republic
| | - Tomáš Slanina
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague, Czech Republic
| | - Josef Wachtveitl
- Institute of Physical and Theoretical Chemistry, Goethe University, Max-von-Laue Straße 7, 60438, Frankfurt am Main, Germany
| | - Eliška Procházková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague, Czech Republic
| | - Marek Cigáň
- Institute of Chemistry, Comenius University, Ilkovičova 6, 84215, Bratislava, Slovakia
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30
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Slavov C, Yang C, Heindl AH, Wegner HA, Dreuw A, Wachtveitl J. Thiophenylazobenzene: An Alternative Photoisomerization Controlled by Lone-Pair⋅⋅⋅π Interaction. Angew Chem Int Ed Engl 2020; 59:380-387. [PMID: 31595575 PMCID: PMC6973119 DOI: 10.1002/anie.201909739] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/01/2019] [Indexed: 01/15/2023]
Abstract
Azoheteroarene photoswitches have attracted attention due to their unique properties. We present the stationary photochromism and ultrafast photoisomerization mechanism of thiophenylazobenzene (TphAB). It demonstrates impressive fatigue resistance and photoisomerization efficiency, and shows favorably separated (E)- and (Z)-isomer absorption bands, allowing for highly selective photoconversion. The (Z)-isomer of TphAB adopts an unusual orthogonal geometry where the thiophenyl group is perfectly perpendicular to the phenyl group. This geometry is stabilized by a rare lone-pair⋅⋅⋅π interaction between the S atom and the phenyl group. The photoisomerization of TphAB occurs on the sub-ps to ps timescale and is governed by this interaction. Therefore, the adoption and disruption of the orthogonal geometry requires significant movement along the inversion reaction coordinates (CNN and NNC angles). Our results establish TphAB as an excellent photoswitch with versatile properties that expand the application possibilities of AB derivatives.
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Affiliation(s)
- Chavdar Slavov
- Institute of Physical and Theoretical ChemistryGoethe UniversityFrankfurt am MainGermany
| | - Chong Yang
- Interdisciplinary Center for Scientific Computing (IWR)University of HeidelbergHeidelbergGermany
| | - Andreas H. Heindl
- Institute of Organic ChemistryCenter for Materials Research (LaMa)Justus Liebig UniversityGiessenGermany
| | - Hermann A. Wegner
- Institute of Organic ChemistryCenter for Materials Research (LaMa)Justus Liebig UniversityGiessenGermany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing (IWR)University of HeidelbergHeidelbergGermany
| | - Josef Wachtveitl
- Institute of Physical and Theoretical ChemistryGoethe UniversityFrankfurt am MainGermany
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