DOCSLIB.ORG

Improving the Design of Diarylethene Photoswitches and Their Exploitation As Remote-Controlled Building Blocks

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Improving the Design of Diarylethene Photoswitches and Their Exploitation As Remote-Controlled Building Blocks Improving the Design of Diarylethene Photoswitches and their Exploitation as Remote-Controlled Building Blocks DISSERTATION zur Erlangung des akademischen Grades doctor rerum naturalium (Dr. rer. nat.) im Fach Chemie eingereicht an der Mathematisch-Naturwissenschaftlichen Fakultät der Humboldt-Universität zu Berlin von Dipl.-Chem. Martin Herder Präsident der Humboldt-Universität zu Berlin Prof. Dr. Jan-Hendrik Olbertz Dekan der Mathematisch-Naturwissenschaftlichen Fakultät Prof. Dr. Elmar Kulke Gutachter: 1. Prof. Stefan Hecht, Ph.D. 2. Prof. Dr. Nikolaus P. Ernsting 3. Prof. Dr. Ben L. Feringa Tag der mündlichen Prüfung: 20.04.2015 Die vorliegende Arbeit wurde in der Zeit von Oktober 2010 bis Februar 2015 am Institut für Chemie der Humboldt-Universität zu Berlin unter der Anleitung von Prof. Stefan Hecht, Ph.D. angefertigt. Danksagung An dieser Stelle möchte ich mich bei allen bedanken, die mich bei der Anfertigung meiner Dissertation tatkräftig unterstützt haben. Besonderer Dank gilt Prof. Stefan Hecht für das große in mich gesetzte Vertrauen, die zahlreichen Gespräche, in denen ich sehr viel gelernt habe und immer motiviert wurde, die hervorragenden Arbeitsbedingungen und die stete Hilfe bei Problemen jeder Art. Allen derzeitigen und ehemaligen Mitgliedern der Arbeitsgruppe danke ich für die tolle Arbeitsatmosphäre, die gegenseitige Unterstützung und den freundschaftlichen Umgang im und außerhalb des Labors. Ein großer Dank geht an Micha und Lutz. Danke für die enge Zusammenarbeit, die vielen wissenschaftlichen und nicht-wissenschaftlichen Gespräche, die zahlreichen spektroskopischen und elektrochemischen Messungen, die große Unterstützung für meine Arbeit und dafür, immer ein offenes Ohr zu haben. Meinen Laborkollegen Robert, Sonia, Henry, Anne, Bernd, Fabian und Derk-Jan gilt großer Dank für die tolle Zusammenarbeit, den (meist) exzellenten Musikgeschmack und dafür über lange Tage das Rotlicht ausgehalten zu haben. Philipp danke ich für die Freundschaft und die zahlreichen leidenschaftlichen Gespräche über Chemie und anderes, Björn für die eine oder andere Lektion im Skat und Doppelkopf sowie für die schönen Abende im Garten und Robert für die inspirierende Zusammenarbeit und Unterstützung. Bei Herrn Leistner möchte ich mich für die stete Hilfe bei analytischen Problemen bedanken. Für die synthetische Unterstützung bedanke ich mich bei Jutta, Jana und Henry. Meiner Forschungspraktikantin Anne sowie meinen Bachelorstudenten Fabian und Anna danke ich für das Engagement und die gute Zusammenarbeit. Großer Dank gilt auch allen Mitarbeitern in den analytischen Abteilungen des Instituts für Chemie, deren tägliche Arbeit die Grundlage für meine Dissertation ist. Vielen Dank auch an die Korrekturleser meiner Arbeit Maren, Philipp und Fabian. I am very grateful to Prof. Paolo Samorì and the people in his group, especially Emanuele, Núria, Mirella, Karl, Sara and Thomas, for the very inspiring and fruitful collaboration. Manuel Utecht danke ich für quantenmechanische Rechnungen sowie Johannes Frisch für die UPS Messungen. Ein herzlicher Dank gilt meiner Familie, die mir das Studium ermöglicht und mich immer unterstützt hat. Meinen Freunden und Kommilitonen danke ich für die schöne Zeit während meines Studiums und meiner Promotion. Zu guter Letzt möchte ich einen ganz besonderen Dank an Maren richten. Vielen Dank für deine Liebe, dein Vertrauen und die Kraft, die du mir gibst. Abstract Among molecular units that can be reversibly switched between two states by light, diarylethenes have the unique property that the π-electronic structure of their molecular backbone significantly alters during the isomerization process, resulting in a marked shift of HOMO and LUMO levels. The incorporation of diarylethene switches into more complex molecular systems would allow for the reversible light-controlled manipulation of specific functions, such as catalytic activity, association behavior, or charge transport, due to the modulation of inherent electronic properties. However, to fulfill this task the photochromic scaffold has to be improved in terms of its switching efficiency, fatigue resistance, and extent of electronic modulation. In this work, a series of diarylethenes is synthesized by systematically varying the constituents of the hexatriene core and the terminal substituents. By the in-depth characterization of the photochemical reaction to a by-product, an ubiquitous phenomenon of diarylethene photochromism, fatigue resistant structures are identified that allow for the reliable operation of the photochrome over many switching cycles and at the same time guarantee a high degree of structural and synthetic flexibility. Furthermore, a distinct substitution pattern is found to enable the orthogonal electro- and photochemically mediated isomerization of diarylethenes. By proper modulation of the structure, the fatigue observed during the oxidative cyclization reaction is minimized and insights into the underlying mechanism are gained. The impact of different substitution patterns on the -electronic structure of the diarylethene core is studied and it is shown that HOMO and LUMO levels can be tuned over a broad energy range. Finally, the electronically tuned diarylethenes are applied as active building blocks in light-controllable organic thin film transistors, which show a modulation of the output current upon isomerization of the photochrome. In a second approach to exploit the isomerization induced electronic modulations, a potentially catalytically active guanidine unit is coupled to the diarylethene core in order to construct a photoswitchable organocatalyst. Kurzzusammenfassung Unter Molekülen, die durch Licht reversibel zwischen zwei Zuständen geschaltet werden können, haben Diarylethene die einzigartige Eigenschaft, dass ihr -Elektronensystem durch den Isomerisierungsprozess stark verändert wird, was zu einer Verschiebung von HOMO und LUMO Niveaus führt. Die Verwendung von Diarylethenen in komplexeren Systemen würde die Steuerung von bestimmten Funktionen, wie katalytische Aktivität, supramolekulare Assoziation oder Ladungstransport, mit Hilfe von Licht durch die Änderung inhärenter elektronischer Eigenschaften ermöglichen. Allerdings muss die photochrome Baueinheit den spezifischen Anforderungen angepasst und ihre Schalteigenschaften, die Ermüdungsresistenz sowie das Ausmaß der elektronischen Modulation verbessert werden. In dieser Arbeit wird durch systematische Variation der zentralen Komponenten und der terminalen Substituenten eine Serie von elektronisch modulierten Diarylethenen synthetisiert. Durch umfangreiche Untersuchungen zur photochemischen Bildung eines Nebenprodukts, ein Prozess der bei nahezu allen Diarylethenen auftritt, können Strukturen identifiziert werden, die über eine große Zahl von Schaltzyklen ermüdungsresistent sind und gleichzeitig eine hohe strukturelle und synthetische Flexibilität bieten. Weiterhin erlauben bestimmte Substitutions- muster die orthogonale elektro- und photochemische Steuerung des Isomerisierungsprozesses. Durch geeignete strukturelle Modulation wird die Nebenproduktbildung bei der oxidativen Zyklisierungsreaktion unterdrückt und es kann ein Einblick in den zugrunde liegenden Mechanismus erhalten werden. Der Einfluss verschiedener Substitutionsmuster auf das -Elektronensystem von Diarylethenen wird untersucht und es wird gezeigt, dass HOMO und LUMO Level über einen großen Energiebereich moduliert werden können. Schließlich werden die so erhaltenen, elektronisch modulierten Diarylethene als aktive Elemente in Licht gesteuerten organischen Dünnschichttransistoren eingesetzt. Diese zeigen eine Änderung im Strom-Ausgangssignal durch die lichtinduzierte Isomerisierung der photochromen Moleküle. In einem zweiten Ansatz die schaltbaren elektronischen Änderungen in Diarylethenen zu nutzen, wird ein potentiell katalytisch aktives Guanidin mit der photochromen Einheit gekoppelt, mit dem Ziel einen photoschaltbaren Organokatalysator zu konstruieren. Table of contents 1. Introduction ............................................................................................................... 1 2. Theoretical background ............................................................................................. 5 2.1 Diarylethene photoswitches ................................................................................ 5 2.1.1 General structure-property relationships ................................................... 5 2.1.2 Excited state properties .............................................................................. 9 2.1.3 Fatigue behavior ...................................................................................... 13 2.1.4 Electrochemical properties ...................................................................... 15 2.2 Application of diarylethenes to remote-control functions ................................ 18 2.2.1 General principles .................................................................................... 18 2.2.2 Diarylethenes in organic electronic devices ............................................ 20 2.2.3 Diarylethenes for reactivity control and catalysis ................................... 23 3. Motivation ............................................................................................................... 27 4. Results and Discussion ............................................................................................ 31 4.1 Synthesis of all DAE derivatives .....................................................................
Load more

Recommended publications
  • The Use of Diarylethene Derivatives for Photo-Switching
    Contribution The use of Diarylethene Derivatives for Photo-switching Kenji Matsuda Masahiro Irie Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University 1. Introduction The color change is attributable to the different electrical structures between the open-ring and closed-ring The process of reversible coloration changes induced isomers. In the open-ring isomers, free rotation exists at at least in one-direction by photoirradiation is referred to the ethene and aryl groups, so the isomer is non-planar as photochromism.1) The two isomers of photochromic com- and the π-electrons are localized in the two aryl groups. pounds differ in their geometrical and electrical structures. Furthermore, due to rotational energy barriers, two rota- These geometrical and electrical differences lead to tional isomers exist, namely, photo-reactive (anti-parallel) changes in the physical properties of the molecules, such and photo-inactive (parallel) (Figure 2).3) On the other hand, as their absorption and fluorescence spectra, refractive the closed ring isomer possesses high planarity, with index and electrical conductivity. Since the transformation asymmetrically arranged carbon atoms at the reaction site. between the isomers is induced by photoirradiation, It has a bond alternation polyene structure and a π-conju- optical-switching of the physical properties can be realized gated system spread throughout the molecule. Reflecting by using the photochromic units. on the differences between these geometric and electrical Diarylethene, which contains five-membered structures, their physical properties vary in many ways.4) heterocyclic rings, is well known as a photochromic com- In this review, some of the physical properties that were pound that is thermo-irreversible, has high-sensitivity and photo-switched by using photochromic diarylethene units, has fatigue resistance properties.2) Photochromic reactions i.e.
    [Show full text]
  • Alginate and Silk Fibroin Based Technologies for Biosensing
    ADVERTIMENT. Lʼaccés als continguts dʼaquesta tesi queda condicionat a lʼacceptació de les condicions dʼús establertes per la següent llicència Creative Commons: http://cat.creativecommons.org/?page_id=184 ADVERTENCIA. El acceso a los contenidos de esta tesis queda condicionado a la aceptación de las condiciones de uso establecidas por la siguiente licencia Creative Commons: http://es.creativecommons.org/blog/licencias/ WARNING. The access to the contents of this doctoral thesis it is limited to the acceptance of the use conditions set by the following Creative Commons license: https://creativecommons.org/licenses/?lang=en ALGINATE AND SILK FIBROIN BASED TECHNOLOGIES FOR BIOSENSING Augusto Márquez Maqueda Doctoral Thesis PhD in Chemistry Supervised by: Dr. Xavier Muñoz Berbel Dr. Carlos Domínguez Horna Tutored by: Dr. Julián Alonso Chamorro Departament de Química Facultat de Ciències 2020 The present thesis, entitled “Alginate and Silk Fibroin based Technologies for Biosensing”, is submitted by Augusto Márquez Maqueda as a partial fulfilment of the requirements for the Doctor of Philosophy degree in Chemistry. This thesis was carried out at the Institute of Microelectronics of Barcelona (IMB-CNM, CSIC), in the Group of Chemical Transducers (GTQ), under the supervision of Dr. Xavier Muñoz Berbel and Dr. Carlos Domínguez Horna. This thesis was supported by the Spanish R & D National Program (MEC Project TEC2014-54449-C3-1-R) and by the MICINN for the award of a research studentship within the FPI program (BES-2015-072946). With the approval of: Dr. Xavier Muñoz Berbel Dr. Carlos Domínguez Horna (Director) (Director) Dr. Julián Alonso Chamorro Augusto Márquez Márquez (Tutor) (Author) Agradecimientos Son muchas las personas a las que he de agradecer el hecho de haber podido realizar esta tesis.
    [Show full text]
  • Design, Synthesis and Applications of Responsive Macrocycles
    REVIEW ARTICLE https://doi.org/10.1038/s42004-020-00438-2 OPEN Design, synthesis and applications of responsive macrocycles ✉ Jingjing Yu1, Dawei Qi1 & Jianwei Li 1,2 1234567890():,; Inspired by the lock and key principle, the development of supramolecular macrocyclic chemistry has promoted the prosperous growth of host-guest chemistry. The updated induced-fit and conformation selection model spurred the emerging research on responsive macrocycles (RMs). This review introduces RMs, covering their design, synthesis and applications. It gives readers insight into the dynamic control of macrocyclic molecules and the exploration of materials with desired functions. ost–guest chemistry grew out of the lock and key principle by Emil Fischer. The principle Hwas formulated in 1894 by his discovery that glycolytic enzymes could selectively recognize stereoisomers of sugars. He hypothesized that only when the geometry of the enzyme (lock) was exactly complementary with that of the substrate (key) could the recognition take place and subsequently trigger the catalytic reactions. This model not only helps us understand the basics of biochemistry but also encourages chemists to explore functional host molecules acting like the ‘lock’. The first family of artificial host molecules, crown ethers, was discovered by Charles Pederson in 19671. They were cyclic molecules, and certain metallic atoms can be bonded in the middle of the ring of these molecules. Since then, supramolecular chemists have developed many macrocycles, including natural molecules like cyclodextrins2 and syn- thesized ones, including cucurbiturils3, pillararenes4, asararenes5, calixarenes6, resorcinarenes7 and other novel supramolecular macrocycles8–10. These macrocycles and their derivatives have been extensively investigated so chemists are able to achieve structure specific and highly selective recognition properties, which provide opportunities for exploring advanced applica- tions in sensing11, transport12, catalysis13 and drug/gene delivery14.
    [Show full text]
  • Rylene Bisimide-Diarylethene Photochromic Systems for Non-Destructive Memory Read-Out
    Rylene Bisimide-Diarylethene Photochromic Systems for Non-destructive Memory Read-out Dissertation zur Erlangung des naturwissenschaftlichen Doktorgrades der Julius-Maximilians-Universität Würzburg vorgelegt von Martin Berberich aus Amorbach Würzburg 2012 2 Eingereicht bei der Fakultät für Chemie und Pharmazie am: 10.08.2012 1. Gutachter: Prof. Dr. Frank Würthner 2. Gutachter: Prof. Dr. Markus Sauer der schriftlichen Arbeit 1. Prüfer: Prof. Dr. Frank Würthner 2. Prüfer: Prof. Dr. Markus Sauer 3. Prüfer: Prof. Dr. Tobias Brixner des öffentlichen Promotionskolloquiums Tag des öffentlichen Promotionskolloquiums: 29.10.2012 Doktorurkunde ausgehändigt am: _________________________ 3 4 Wer nichts als Chemie versteht, versteht auch die nicht recht. ca. 1790 Georg Christoph Lichtenberg (1742–1799) 5 List of Abbreviations List of Abbreviations A acceptor AIBN azobisisobutyronitrile APCI atmospheric-pressure chemical ionization BOC N-tert-butoxycarbonyl c closed form of photochrome CI conical intersection CT charge transfer CV cyclic voltammetry D donor DAE diarylethene DAEC closed form of diarylethene DAEO open form of diarylethene DBN 1,5 diazabicyclo[4.3.0]non-5-ene DCC N,N’-dicyclohexylcarbodiimide DCTB 2-[(2E)-3-(4-tert-butylphenyl)-2-methylprop-2-enylidene]malononitrile diglyme 1-methoxy-2-(2-methoxyethoxy)ethane DMF N,N-dimethylformamide DMSO dimethyl sulfoxide ESI electrospray ionization FRET Förster resonance energy transfer FWHM full width half maximum HOMO highest occupied molecular orbital HRMS high resolution mass spectrometry IC internal
    [Show full text]
  • Organic Photochromic Compounds
    Organic Photochromic Compounds Literature talk 11.07.2018 Lisa-Catherine Rosenbaum, Gaich group Universität Konstanz Introduction „Photochromism“ (from Greek phos = light, chroma = color; Hirshberg, 1950) : light-induced reversible transformation of a chemical species between two forms with different absorption spectra Photochromic action: • photo-induced darkening • thermally induced reverse reaction which leads to initial transparent state - from 1960s: glass lenses impregnated with silver halides and cuprous ions (photolytic decomposition of silver halide; reversible broad absorption band from UV to near IR) - nowadays: organic photochromic lenses H. Dürr, H. Bouas-Laurent, Photochromism: Molecules and Systems , Elsevier Science, 2003 . https://www.zeiss.com/vision-care/int/better-vision/lifestyle-fashion/fast-dark-fast-clear-modern-self-tinting-lenses.html , taken on 13.06.2018 2 11.07.2018 Organic Photochromic Compounds Universität Konstanz Historical Survey Photochromic phenomena first reported by J. Fritsche (1867): Chancel (1878), Hantzsch (1907): chromoisomerism E. ter Meer (1876): (structure isomerism of “chromo -dinitro salts”) Fainzil’berg (1975): reversible formation of K-salt of ethylnitrolic acid R. Hubbard, A. Kropf (1958): photoexcitation in the process of vision 1960s: development of physical methods (UV, IR, NMR, X-Ray, time-resolved and flash spectroscopy) and organic synthesis mechanistic and synthetic studies; limited potential applications (photodegradation), stagnation of research 1980s: fatigue-resistant photoswitches (spirooxazines and chromenes), fabrication and commercial application of photochromic lenses and other systems J. Fritsche, Comptes Rendus Acad. Sci. 1867 , 69 , 1035. E. t. Meer, Justus Liebigs Ann. Chem. 1876 , 181 , 1-22. H. A., Ber. Dt. Chem. Ges. 1907 , 40 , 1533-1555. V. I. Slovetskii, V. P. Balykin, O.
    [Show full text]
  • Photochromic Diarylethene As an Information Processing Unit: Magnetic and Electric Switching*
    Pure Appl. Chem., Vol. 80, No. 3, pp. 555–561, 2008. doi:10.1351/pac200880030555 © 2008 IUPAC Photochromic diarylethene as an information processing unit: Magnetic and electric switching* Kenji Matsuda Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan Abstract: Photochromic compounds reversibly change not only the absorption spectra but also their geometrical and electronic structures. This principle can be applied for the photo- switching of the physical properties of the molecular materials. In particular, photoswitching of the flow of information through the molecule is interesting because information process- ing using molecular devices is attracting interest in the molecular electronics field. The photoswitchings of the magnetic exchange interaction and the electrical conductance using photochromic diarylethene are described. Keywords: photochromism; magnetism; exchange interaction; electric conductance; gold nanoparticles. INTRODUCTION Photochromism is a reversible phototransformation of a chemical species between two forms having different absorption spectra [1–4]. Photochromic compounds reversibly change not only the absorption spectra but also their geometrical and electronic structures. The geometrical and electronic structural changes induce some changes in physical properties, such as fluorescence, refractive index, polariz- ability, and electric conductivity. Diarylethenes with heterocyclic aryl groups are well known as thermally irreversible, highly sen- sitive, and fatigue-resistant photochromic compounds [5,6]. The photochromic reaction is based on a reversible transformation between an open-ring isomer with hexatriene structure and a closed-ring iso- mer with cyclohexadiene structure according to the Woodward–Hoffmann rule as shown in Fig. 1. While the open-ring isomer 1a is colorless in most cases, the closed-ring isomer 1b has the color of yel- low, red, or blue, depending on the molecular structure.
    [Show full text]
  • Dual Wettability on Diarylethene Microcrystalline Surface Mimicking a Termite Wing
    ARTICLE Corrected: Publisher Correction https://doi.org/10.1038/s42004-019-0192-6 OPEN Dual wettability on diarylethene microcrystalline surface mimicking a termite wing Ryo Nishimura 1, Kengo Hyodo1, Hiroyuki Mayama 2, Satoshi Yokojima3,4, Shinichiro Nakamura 4 & Kingo Uchida 1,4 1234567890():,; The termite wing has a specific property of wetting in contact with a water droplet: it adsorbs water mist, whereas larger water droplets are bounced on the surface. This is owing to the survival strategy of termites. Here, we reproduce the termite wing’s dual wettability by a photoinduced crystal growth technique. Upon UV irradiation to a microcrystalline surface of a mixture of two diarylethenes, two types of needle-shaped crystals of distinctly different sizes are observed to grow. The surface shows behavior akin to the termite wing’s dual wettability. The bouncing ability of a water droplet is attributed to the smaller-sized needle crystals, whereas the adhesive property is owing to the larger-sized ones, explaining the micro- structures of the termite wing. Considering dissipation energy and adhesion energy, the bouncing ability and dual wettability can be explained theoretically. The surface could potentially be used in water harvesting applications. 1 Department of Materials Chemistry, Ryukoku University, Seta, Otsu, Shiga 520-2194, Japan. 2 Department of Chemistry, Asahikawa Medical University, 2-1- 1-1 Midorigaoka–higashi, Asahikawa, Hokkaido 078-8510, Japan. 3 School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan. 4 RIKEN Cluster for Science, Technology and Innovation Hub, Nakamura Laboratory, 2-1 Hirosawa, Wako, Saitama 351- 0198, Japan.
    [Show full text]
  • Partially Fluorinated Polycyclic Aromatic Compounds: Synthesis and Supramolecular Behavior
    University of Kentucky UKnowledge University of Kentucky Master's Theses Graduate School 2007 PARTIALLY FLUORINATED POLYCYCLIC AROMATIC COMPOUNDS: SYNTHESIS AND SUPRAMOLECULAR BEHAVIOR Don Mark Cho University of Kentucky, [email protected] Right click to open a feedback form in a new tab to let us know how this document benefits ou.y Recommended Citation Cho, Don Mark, "PARTIALLY FLUORINATED POLYCYCLIC AROMATIC COMPOUNDS: SYNTHESIS AND SUPRAMOLECULAR BEHAVIOR" (2007). University of Kentucky Master's Theses. 443. https://uknowledge.uky.edu/gradschool_theses/443 This Thesis is brought to you for free and open access by the Graduate School at UKnowledge. It has been accepted for inclusion in University of Kentucky Master's Theses by an authorized administrator of UKnowledge. For more information, please contact [email protected]. ABSTRACT OF THESIS PARTIALLY FLUORINATED POLYCYCLIC AROMATIC COMPOUNDS: SYNTHESIS AND SUPRAMOLECULAR BEHAVIOR The field of organic electronics has received much attention over the last few years, and engineering of organic crystals to grow with pi-electron systems arranged in a face-to- face motif has been shown to be beneficial in electronic devices. The effects of combining aromatic and perfluorinated aromatic derivatives have shown that the intramolecular stacking pattern can be changed from an edge-to-face arrangement to that of a face-to-face motif. Before the work described herein, there were no reported studies of the supramolecular behavior of fused polycyclic aromatic compounds with partial peripheral fluorination, inducing the desired face-to-face behavior. This is the main focus of the thesis. Furthermore, by exploiting the interactions between the fluorinated and non-fluorinated faces of the molecule, columnar liquid crystalline behavior can be achieved through variations of the alkyl substituents on the molecule.
    [Show full text]
  • Hybrid Organic–Inorganic Photon-Powered Actuators Based
    Article Cite This: Chem. Mater. 2019, 31, 1016−1022 pubs.acs.org/cm Hybrid Organic−Inorganic Photon-Powered Actuators Based on Aligned Diarylethene Nanocrystals † † † ‡ † § Xinning Dong, Fei Tong, Kerry M. Hanson, Rabih O. Al-Kaysi, Daichi Kitagawa,*, , § † Seiya Kobatake,*, and Christopher J. Bardeen*, † Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, California 92521, United States ‡ College of Science and Health Professions-3124, King Saud bin Abdulaziz University for Health Sciences, and King Abdullah International Medical Research Center, Ministry of National Guard Health Affairs, Riyadh 11426, Kingdom of Saudi Arabia § Department of Applied Chemistry, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan *S Supporting Information ABSTRACT: When photochromic molecules are organized in a crystal, the small-scale forces generated by molecular photoisomerization events can combine together to generate work on micro- or macroscopic length scales. In this work, photomechanical nanocrystals themselves are organized on macroscopic length scales using a porous inorganic template. The organic diarylethene component provides the reversible photoresponse, whereas the porous alumina component provides structural support and directionality. This hybrid organic−inorganic photomechanical material acts as a bending actuator. Using ultraviolet and visible photons as power inputs, as little as 0.1 mg of reacted material generates enough force to tilt a 1.28 g mirror and steer a laser beam. The motion can be cycled multiple times in air and under water. Actuator figures- of-merit such as energy-to-work conversion efficiency and stiffness are probably limited by the high elastic modulus of the inorganic template, providing an obvious pathway for optimization.
    [Show full text]
  • Photochromic Diarylethene Molecules and Crystals*
    Pure Appl. Chem., Vol. 81, No. 9, pp. 1655–1665, 2009. doi:10.1351/PAC-CON-08-09-26 © 2009 IUPAC, Publication date (Web): 10 August 2009 Photochromic diarylethene molecules and crystals* Masahiro Irie‡ and Masakazu Morimoto Department of Chemistry and Research Center for Smart Molecules, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan Abstract: Some of the diarylethene derivatives were found to undergo photoisomerization re- actions between two isomers even in the single-crystalline phase. The two isomers have dif- ferent electronic as well as geometrical structures. The electronic structure change induces the reversible color change of the crystal. Single crystals composed of three different kinds of diarylethenes having similar geometrical structures, bisoxazolylethene, bisthiazolylethene, and bisthienylethene have been prepared. The crystals exhibited multicolor photochromism. The colorless crystals turned yellow, red, and blue upon irradiation with the appropriate wavelength of light. The geometrical structure change of component diarylethene molecules in crystals induces reversible surface morphology as well as shape and size changes of the crystals. The photoinduced geometrical structure changes of the molecules in the densely packed crystals were successfully linked to the macro-scale mechanical motion of the solid crystals and resulted in the net task of launching a tiny silica particle. Keywords: diarylethenes; photochromism; photomechanical effects; single crystals; X-ray crystallographic analysis. INTRODUCTION Photochromism is defined as a reversible transformation of a chemical species between two isomers upon irradiation with the appropriate wavelength of light [1,2]. The two isomers have different elec- tronic as well as geometrical structures. The reversible and quick structure changes between them upon photoirradiation can be potentially applied to various photoactive devices [3–7].
    [Show full text]
  • Photomechanical Azobenzene Crystals
    crystals Review Photomechanical Azobenzene Crystals Takuya Taniguchi 1 , Toru Asahi 2,3 and Hideko Koshima 3,* 1 Center for Data Science, Waseda University, 27 Waseda-cho, Shinjuku-ku, Tokyo 1620042, Japan 2 Department of Advanced Science and Engineering, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 1698555, Japan 3 Research Organization for Nano & Life Innovation, Waseda University, 513 Wasedatsurumaki-cho, Shinjuku-ku, Tokyo 1620041, Japan * Correspondence: [email protected]; Tel.: +81-3-5286-8307 Received: 12 August 2019; Accepted: 20 August 2019; Published: 22 August 2019 Abstract: Photomechanically responsive materials are promising candidates for future smart actuator applications. The photo-responsive behaviors originate from the photoisomerization of photochromic molecules. A typical photochromic compound, azobenzene, has been studied extensively in the solution state and has played a crucial role in the photomechanical behaviors of materials such as polymers and gels, via chemical bridging with their matrix. In contrast to polymers and gels, the photomechanical attributes of molecular crystals have not progressed to the same degree, due to their rigidity and fragility. However, the past decade has witnessed an increasing number of reports of the photomechanical motion of molecular crystals, including azobenzene crystals. This paper reviews the current state-of-the-art of mechanically responsive azobenzene crystals, including the history, crystal design strategy, and future promising applications. Keywords: azobenzene; photomechanical motion; trans-cis photoisomerization; molecular crystal; actuation 1. Introduction to Photomechanical Materials 1.1. Actuator Materials Actuation, which refers to mechanical motion or operation resulting from an energy conversion process, is prevalent throughout nature and characterizes some human activities.
    [Show full text]
  • A New Diarylethene with Donor-Acceptor Group Bull
    A New Diarylethene with Donor-acceptor Group Bull. Korean Chem. Soc. 2008, Vol. 29, No. 4 827 A New Diarylethene with Donor-acceptor Group for Reversible Photo-induced Electrochemical Switching Eunkyoung Kim,* Miyoung Kim： and Kyongtae Kim* Department of Chemical Engineering, Yonsei University, Seoul 120-749, Korea. *E-mail: eunkim @yonsei.ac.kr ‘School of Chemistry and Molecular Engineering, Seoul National University, Seoul 151-742, Korea Received January 15, 2008 A new diarylethene compound with donor and acceptor substituent was synthesized from 2,3-bis(2-methyl- benzo[b]thiophene-3-yl)hexafluorocyclopentene (BTF) over 5 steps. The donor-acceptor structured BTF compound (TBTFE) showed spectral change to a longer wavelength through photochromism with a high cyclization quantum yield (0.56). The 3,4-ethylenedioxythiophene (T) and carboethoxy (E) groups directly connected to BTF unit promoted electrical change accompanied with the photoisomerization of the BTF unit. Photo-induced electrical switching was achieved from a photocell containing TBTFE doped polymer film, which showed reversible and stable current change over repeated cycles by the alternative UV/Vis irradiation, as estimated by the I-V plot. Key Words : Photochromism, Diarylethene, Ring cyclization, Ring opening, Photo-electrical switching Introduction properties and electrical conductivity of diarylethene through the conjugated pathway. In particular, introduction Photo-induced changes of physical properties between of the electron-donating and -accepting groups to the two
    [Show full text]