WEKO3
アイテム
{"_buckets": {"deposit": "63490a3b-11d4-48a1-a67e-fbf26ac2c470"}, "_deposit": {"created_by": 21, "id": "1486", "owners": [21], "pid": {"revision_id": 0, "type": "depid", "value": "1486"}, "status": "published"}, "_oai": {"id": "oai:ir.soken.ac.jp:00001486", "sets": ["9"]}, "author_link": ["0", "0", "0"], "item_1_biblio_info_21": {"attribute_name": "書誌情報(ソート用)", "attribute_value_mlt": [{"bibliographicIssueDates": {"bibliographicIssueDate": "2009-09-30", "bibliographicIssueDateType": "Issued"}, "bibliographic_titles": [{}]}]}, "item_1_creator_2": {"attribute_name": "著者名", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "陳, 龍"}], "nameIdentifiers": [{"nameIdentifier": "0", "nameIdentifierScheme": "WEKO"}]}]}, "item_1_creator_3": {"attribute_name": "フリガナ", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "チン, ロン"}], "nameIdentifiers": [{"nameIdentifier": "0", "nameIdentifierScheme": "WEKO"}]}]}, "item_1_date_granted_11": {"attribute_name": "学位授与年月日", "attribute_value_mlt": [{"subitem_dategranted": "2009-09-30"}]}, "item_1_degree_grantor_5": {"attribute_name": "学位授与機関", "attribute_value_mlt": [{"subitem_degreegrantor": [{"subitem_degreegrantor_name": "総合研究大学院大学"}]}]}, "item_1_degree_name_6": {"attribute_name": "学位名", "attribute_value_mlt": [{"subitem_degreename": "博士(理学)"}]}, "item_1_description_1": {"attribute_name": "ID", "attribute_value_mlt": [{"subitem_description": "2009507", "subitem_description_type": "Other"}]}, "item_1_description_12": {"attribute_name": "要旨", "attribute_value_mlt": [{"subitem_description": " Studies on π-electronic molecules have been one of the important subjects in\u003cbr /\u003eorganic electronics and optoelectronics. Introduction of metal modules to conjugated\u003cbr /\u003emolecules plays an important role in expanding the diversity of supramolecular self-\u003cbr /\u003eassembly. For example, properties of metal ions such as magnetism, redox, and\u003cbr /\u003ephotochemical activities may be transcribed on the supramolecules. This thesis\u003cbr /\u003ereports a general strategy for the integration of metal species to π-electronic\u003cbr /\u003ecompounds via conjugation. It demonstrates the first synthesis of conjugated\u003cbr /\u003emultinuclear metallo complexes and their assemblies to form two-dimensional\u003cbr /\u003emolecular tapes and sheets with unique electronic and photo functionalities. In\u003cbr /\u003erelation to these hole-transporting supermolecules, this thesis reports a new kind of n-\u003cbr /\u003etype conducting molecules with robust thermal stability, high processability, and large\u003cbr /\u003eelectron mobility. These unique properties are unprecedented and highly correlated\u003cbr /\u003ewith their well-defined supramolecular architectures.\u003cbr /\u003e Along this line, I reports the development of novel functional macromolecules\u003cbr /\u003evia topological design, by focusing on the creation of a new class two-dimensional\u003cbr /\u003epolymers and the finding of light-harvesting effect of conjugated microporous\u003cbr /\u003epolymers. Exploration of functional macromolecules is one of the interesting and\u003cbr /\u003ecentral topics in chemistry, physics, and molecular science. Especially, π-electronic\u003cbr /\u003emacromolecules are indispensable in molecular devices such as biosensors, light-\u003cbr /\u003eemitting diodes, and plastic solar cells. Their capabilities of triggering emission,\u003cbr /\u003ephotoinduced energy/electron transfers, and charge carrier transportation are key\u003cbr /\u003efactors that vitalize device performance. Various 1D conjugated polymers have been\u003cbr /\u003edeveloped for these purposes, while the molecular design of 3D conjugated polymers\u003cbr /\u003ehas led to unique dendritic scaffolds for cascade energy transduction. To access 2D\u003cbr /\u003epolymeric architecture, elaborate modifications of 1D conjugated polymers have led\u003cbr /\u003e to findings of 2D anisotropic monolayers and thin films by SAM, LB, and LBL\u003cbr /\u003e techniques. Clearly, a covalent 2D polymer assures a robust and shape-persistent\u003cbr /\u003epolymer network with permanent order in its building blocks. Synthesis of such\u003cbr /\u003ecovalent 2D polymers has been heavily pursed since they are expected to open\u003cbr /\u003eentirely new vistas for future science and technology. However, the existence of\u003cbr /\u003e covalent 2D polymers has not yet been proved and the development of a realistic way\u003cbr /\u003eto create such polymers remains a major challenge. This thesis describes the first\u003cbr /\u003e example of the synthesis of a covalent two-dimensional (2D) conjugated polymer,\u003cbr /\u003ewhich is a completely new class of polymer.\u003cbr /\u003e As summarized in the above, my thesis consists of the design, synthesis, and\u003cbr /\u003efunctional exploration of supermolecules and macromolecules, with an emphasis on\u003cbr /\u003ethe development of novel π-electronic nanoarchitectures.\u003cbr /\u003e\u003cbr /\u003e\u003cb\u003e(1)The Noncovalent Assembly of Benzene-Bridged Metallosalphen Dimer:\u003cbr /\u003ePhotoconductive Tapes with Large Carrier Mobility and Spatially Distinctive\u003cbr /\u003eConduction Anisotropy\u003cbr /\u003e\u003c/b\u003e In photoconduction, photo-generated charge carriers move to electrodes and\u003cbr/\u003eproduce electric current. Studies on such photo-responsive molecules have been an\u003cbr /\u003eimportant part of progress in the field of solar energy conversion. Single crystals of\u003cbr /\u003ecertain π-conjugated molecules, \u003ci\u003ee.g.,\u003c/i\u003e arenes, have been reported to become\u003cbr /\u003ephotoconductive as a result of exciton migration and charge separation at the\u003cbr /\u003emolecule-electrode interface. However, small arenes absorb photons only in the\u003cbr /\u003eultraviolet region, while large arenes with absorption bands extending to the visible\u003cbr /\u003eregion require complicated synthesis along with tedious purification and are difficult\u003cbr /\u003eto process. Moreover, the undesirable photoinduced dimerization and bleaching of\u003cbr /\u003earenes deter their application to optoelectronics. During a study on the assembly of\u003cbr /\u003econjugated multinuclear metallocomplexes, I serendipitously discovered that these π-\u003cbr /\u003eelectronic metallo-conjugates are photo-responsive, robust against irradiation and may\u003cbr /\u003eavoid the above drawbacks.In the first part, I describes a newly synthesized benzene-\u003cbr /\u003ebridged metallosalphen dimer tailored with alphatic chains, which is demonstrated for\u003cbr /\u003ethe solution-processed assembly of a π-electronic tape. The tape is unique in that it\u003cbr /\u003eshows a large intrinsic carrier mobility, is spatially anisotropic in conduction, forms\u003cbr /\u003e\u003ci\u003ep-\u003c/i\u003e or \u003c/i\u003en-\u003c/i\u003etype semiconductors tunable upon doping. I emphasizes that the tape is highly\u003cbr /\u003eresponsive to visible light irradiation, triggers prominent photocurrent generation,\u003cbr /\u003eshows on/off ratios as high as 9.0 × 10\u003csup\u003e4\u003c/sup\u003e and is capable of repeated on-off switching\u003cbr /\u003ewithout deterioration. Molecular design of bridged dinuclear metallocomplexes has\u003cbr /\u003eled to the findings of unusual physical properties and utilities such as catalysts,\u003cbr /\u003emimicry for biological enzymes, molecular magnets, building blocks for coordination\u003cbr /\u003epolymers and MOFs. However, photo functions have been unexplored to date.\u003cbr /\u003e\u003cbr /\u003e\u003cb\u003e(2) Noncovalently Netted, Photoconductive Sheets with Extremely High Carrier\u003cbr /\u003eMobility and Conduction Anisotropy from Triphenylene-Fused Metal Trigon\u003cbr /\u003eConjugates\u003cbr /\u003e\u003c/b\u003e Studies on conjugated molecules have been one of the central subjects in organic\u003cbr/\u003eelectronics and optoelectronics. Introduction of metal modules to conjugated\u003cbr /\u003emolecules plays an important role in expanding the diversity of supramolecular self-\u003cbr /\u003eassembly. For example, properties of metal ions such as magnetism, redox, and\u003cbr /\u003ephotochemical activities may be transcribed on the supramolecules. In this context,\u003cbr /\u003etriphenylene, a typical conjugated planar molecule, is an intriguing motif for such a\u003cbr /\u003epurpose due to its utility in supramolecular assembly. However, up to date, metal-\u003cbr /\u003econtaining triphenylene derivatives have been limited to only thio-ligated bismuth and\u003cbr /\u003esilver crystalline solids. In relation to the first part, here, I reports the first example of\u003cbr /\u003etriphenylene-fused metal trigon conjugates, where multinuclear metal sites are\u003cbr /\u003econnected to one another via conjugation with triphenylene core. The metal trigon\u003cbr /\u003eupon self-assembly forms well-defined 2D sheet, which harvests a wide range of\u003cbr /\u003ephotons, converts them to bright emission, and allows exciton migration. Moreover, \u003cbr /\u003ethe 2D sheet is semiconducting with a high carrier mobility and capable of repetitive\u003cbr /\u003e on-off current switching at room temperature. The noncovalent 2D sheet is\u003cbr /\u003e photoconductive to exhibit a quick response to visible light irradiation with large\u003cbr /\u003eon/off ratio. Spatial anisotropy in conductivity reveals that the sheet assembly favors a\u003cbr /\u003econduction path perpendicular to the stacked sheets other than the one along the sheet\u003cbr /\u003eplanes. These characters are unique and clearly originate from the highly ordered\u003cbr /\u003emolecular structure of the noncovalent sheet assembly.\u003cbr /\u003e\u003cbr /\u003e\u003cb\u003e(3)Pyrene-Fused Phenazine Bisimides as Robust, Solution Processable and\u003cbr /\u003eChemically Addressable n-Channel Organic Semiconductors\u003cbr /\u003e\u003c/b\u003e Organic semiconductors have attracted great interests in relation to their utilities\u003cbr /\u003ein optoelectronics and molecular electronics. In contrast to rich varieties of \u003ci\u003ep-\u003c/i\u003etype\u003cbr /\u003esemiconductor, \u003ci\u003en-\u003c/i\u003etype organic semiconductor has been very limited in numbers to\u003cbr /\u003ecertain electron-withdrawing π-conjugation systems including perfluorinated aromatic\u003cbr /\u003ecompounds, heteroaromatic compounds, and fullerene derivatives. Due to electronic\u003cbr /\u003edeficient nature, n-type organic semiconductors are usually unstable and air sensitive\u003cbr /\u003ein conducting condition. Recently, bisimides with aromatic cores such as anthracene,\u003cbr /\u003enaphthalene, perylene, and tetrathiafulvalene moieties have been reported to function\u003cbr /\u003eas n-type semiconductor, which allows supramolecular self-assembly upon tailoring\u003cbr /\u003eat bisimide terminals with alkyl chains to fabricate various nanostructured devices.\u003cbr /\u003eVery recently, phenazine compounds have been demonstrated to be \u003ci\u003en-\u003c/i\u003etype\u003cbr /\u003esemiconductor with high carrier mobility due to the presence of electron-withdrawing\u003cbr /\u003eimine units. In this part, I report a molecular system combining three structural\u003cbr /\u003eparameters (1) bisimide terminals, (2) phenazine linkages, and (3) an extended π-\u003cbr /\u003econjugation pyrene core, \u003ci\u003ei.e.,\u003c/i\u003e pyrene-fused phenazine bisimide as a novel \u003ci\u003en-\u003c/i\u003etype\u003cbr /\u003eorganic semiconductor. I highlights that such a topological design allows a multiple\u003cbr /\u003ecombination of high thermal and air stability, ordered crystalline packing together\u003cbr /\u003ewith facile solution processability. Moreover, protonation of phenazine units leads to\u003cbr /\u003ethe generation of quadruple cationic bisimide, thus converting the conjugated neutral\u003cbr /\u003eskeleton to positively charged backbone. We found that bisimide and cationic\u003cbr /\u003ebisimide are n-type semiconducting with the largest charge carrier mobility of 4.1\u003cbr /\u003ecm\u003csup\u003e2\u003c/sup\u003eV\u003csup\u003e-1\u003c/sup\u003es\u003csup\u003e-1\u003c/sup\u003e and capable of stable repetitive on/off current switching in ambient\u003cbr /\u003econdition.\u003cbr /\u003e\u003cbr /\u003e\u003cb\u003e(4) Synthesis of Covalent Two-Dimensional Polymers Using a Topological Approach\u003c/b\u003e\u003cbr /\u003e Conjugated polymers are commonly used for a wide variety of applications.\u003cbr /\u003eExtensive research has led to the realization of one-dimensional linear and three-\u003cbr /\u003edimensional hyperbranched and dendritic conjugated polymers. Despite tremendous\u003cbr /\u003eefforts, a fully-characterized covalent two-dimensional conjugated polymer has not\u003cbr /\u003eyet been achieved and its creation remains a substantial challenge. In this part I\u003cbr /\u003ereports the synthesis of a two-dimensional conjugated poly(para-phenylene), by\u003cbr /\u003ecovalently \u0027knitting\u0027 one-dimensional linear conjugated chains, based on a specific\u003cbr /\u003etopological two-dimensional cross-coupling polycondensation reaction. This 2D\u003cbr /\u003epolymer is crystalline and consists of flat square sheets with very clear and smooth\u003cbr /\u003eedges. It holds extremely dense interwoven longitudinal and latitudinal straight chains\u003cbr /\u003eof 6.6 × 10\u003csup\u003e6\u003c/sup\u003e cubic micrometer and possesses persistent, long-range, periodic\u003cbr /\u003erepeating-unit order. Electronic experiments and transient conductivity measurements\u003cbr /\u003epredict that two-dimensional conjugated polymers would exhibit completely novel\u003cbr /\u003eproperties when used in molecular electronics and optoelectronics.\u003cbr /\u003e\u003cbr /\u003e\u003cb\u003e(5) Light-Harvesting Conjugated Microporous Polymers: Spatial Confinement\u003cbr /\u003eand Inner Surface-Interfered Energy Transduction\u003c/b\u003e\u003cbr /\u003e Conjugated microporous polymers (CMPs) are amorphous polymers with\u003cbr /\u003econjugated framework and inherent three-dimensional porous structure. Owing to their\u003cbr /\u003eunique pore sizes which could be tuned through molecular design, CMPs serve\u003cbr /\u003eas a bridge between zeolites and MOFs/COFs. However, most studies to date have \u003cbr /\u003emainly focused on the gas storage and separation properties. I envisioned that the\u003cbr /\u003ehighly dense π-electronic components of CMPs framework could serve as antennae\u003cbr /\u003efor collecting photons, while the well-defined inner pores could embed and spatially\u003cbr /\u003econfine energy-accepting counterparts, thus leading to the fabrication of a\u003cbr /\u003esupramolecular system for energy transduction mediated by the large inner surface of\u003cbr /\u003eCMPs. In the last part of this thesis, the author reports the first example of light-\u003cbr /\u003eharvesting CMPs, which consist of microporous polyphenylene framework as\u003cbr /\u003eantennae and coumarin 6 noncovalently encapsulated within the pore as energy-\u003cbr /\u003eaccepting pool. The CMP-based light-harvesting system not only allows the creation\u003cbr /\u003eof a novel noncovalent energy donor-acceptor array but much importantly makes it\u003cbr /\u003epossible a directional pinpoint energy transfer from the framework to the energy\u003cbr /\u003econverter. These characters together with a large inner surface facilitate the energy\u003cbr /\u003etransduction process and result in an almost 100% energy transfer quantum eficiency.\u003cbr /\u003eThese unique properties constitue an important step to the utility of CMPs in sensing\u003cbr /\u003eand optoelectronics.\u003cbr /\u003e Exploration of functional supramolecular and macromolecular nanoarchitectures\u003cbr /\u003eis a subject that has a high probability to lead to the development of new materials. In\u003cbr /\u003esummary, the author has developed a series of novel π-electronic supermolecules and\u003cbr /\u003emacromolecules. The author designed and synthesized a series of new π-electronic\u003cbr /\u003emultinuclear metallo conjugates and n-type conjugated molecules and succeeded in\u003cbr /\u003ethe construction of π-electronic two-dimensional assemblies. By using topological\u003cbr /\u003emolecular design, a new class of polymers, i.e., covalent two-dimensional polymer\u003cbr /\u003ewas created. By exploration of the porous channel, a novel light-harvesting antenna\u003cbr /\u003ebased on conjugated microporous polymers was established. These π-electronic\u003cbr /\u003eorganic architectures show unique photo and electrical functions that clearly originate\u003cbr /\u003efrom their highly ordered structures and thus open a new way to molecular\u003cbr /\u003eoptoelectronics and electronics.", "subitem_description_type": "Other"}]}, "item_1_description_7": {"attribute_name": "学位記番号", "attribute_value_mlt": [{"subitem_description": "総研大甲第1272号", "subitem_description_type": "Other"}]}, "item_1_select_14": {"attribute_name": "所蔵", "attribute_value_mlt": [{"subitem_select_item": "有"}]}, "item_1_select_16": {"attribute_name": "複写", "attribute_value_mlt": [{"subitem_select_item": "印刷物から複写可"}]}, "item_1_select_17": {"attribute_name": "公開状況", "attribute_value_mlt": [{"subitem_select_item": "要旨のみ公開"}]}, "item_1_select_8": {"attribute_name": "研究科", "attribute_value_mlt": [{"subitem_select_item": "物理科学研究科"}]}, "item_1_select_9": {"attribute_name": "専攻", "attribute_value_mlt": [{"subitem_select_item": "07 構造分子科学専攻"}]}, "item_1_text_10": {"attribute_name": "学位授与年度", "attribute_value_mlt": [{"subitem_text_value": "2009"}]}, "item_creator": {"attribute_name": "著者", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "CHEN, Long", "creatorNameLang": "en"}], "nameIdentifiers": [{"nameIdentifier": "0", "nameIdentifierScheme": "WEKO"}]}]}, "item_files": {"attribute_name": "ファイル情報", "attribute_type": "file", "attribute_value_mlt": [{"accessrole": "open_date", "date": [{"dateType": "Available", "dateValue": "2016-02-17"}], "displaytype": "simple", "download_preview_message": "", "file_order": 0, "filename": "甲1272_要旨.pdf", "filesize": [{"value": "663.7 kB"}], "format": "application/pdf", "future_date_message": "", "is_thumbnail": false, "licensetype": "license_11", "mimetype": "application/pdf", "size": 663700.0, "url": {"label": "要旨・審査要旨", "url": "https://ir.soken.ac.jp/record/1486/files/甲1272_要旨.pdf"}, "version_id": "c1322268-0b09-4451-a60d-dad164066b61"}]}, "item_language": {"attribute_name": "言語", "attribute_value_mlt": [{"subitem_language": "eng"}]}, "item_resource_type": {"attribute_name": "資源タイプ", "attribute_value_mlt": [{"resourcetype": "thesis", "resourceuri": "http://purl.org/coar/resource_type/c_46ec"}]}, "item_title": "Design and Functions of Novel Supramolecular and Macromolecular Nanoarchitectures", "item_titles": {"attribute_name": "タイトル", "attribute_value_mlt": [{"subitem_title": "Design and Functions of Novel Supramolecular and Macromolecular Nanoarchitectures"}, {"subitem_title": "Design and Functions of Novel Supramolecular and Macromolecular Nanoarchitectures", "subitem_title_language": "en"}]}, "item_type_id": "1", "owner": "21", "path": ["9"], "permalink_uri": "https://ir.soken.ac.jp/records/1486", "pubdate": {"attribute_name": "公開日", "attribute_value": "2010-06-09"}, "publish_date": "2010-06-09", "publish_status": "0", "recid": "1486", "relation": {}, "relation_version_is_last": true, "title": ["Design and Functions of Novel Supramolecular and Macromolecular Nanoarchitectures"], "weko_shared_id": -1}
Design and Functions of Novel Supramolecular and Macromolecular Nanoarchitectures
https://ir.soken.ac.jp/records/1486
https://ir.soken.ac.jp/records/148639bb09f1-a78e-48c0-b0df-aa234cfa260d
名前 / ファイル | ライセンス | アクション |
---|---|---|
![]() |
Item type | 学位論文 / Thesis or Dissertation(1) | |||||
---|---|---|---|---|---|---|
公開日 | 2010-06-09 | |||||
タイトル | ||||||
タイトル | Design and Functions of Novel Supramolecular and Macromolecular Nanoarchitectures | |||||
タイトル | ||||||
言語 | en | |||||
タイトル | Design and Functions of Novel Supramolecular and Macromolecular Nanoarchitectures | |||||
言語 | ||||||
言語 | eng | |||||
資源タイプ | ||||||
資源タイプ識別子 | http://purl.org/coar/resource_type/c_46ec | |||||
資源タイプ | thesis | |||||
著者名 |
陳, 龍
× 陳, 龍 |
|||||
フリガナ |
チン, ロン
× チン, ロン |
|||||
著者 |
CHEN, Long
× CHEN, Long |
|||||
学位授与機関 | ||||||
学位授与機関名 | 総合研究大学院大学 | |||||
学位名 | ||||||
学位名 | 博士(理学) | |||||
学位記番号 | ||||||
内容記述タイプ | Other | |||||
内容記述 | 総研大甲第1272号 | |||||
研究科 | ||||||
値 | 物理科学研究科 | |||||
専攻 | ||||||
値 | 07 構造分子科学専攻 | |||||
学位授与年月日 | ||||||
学位授与年月日 | 2009-09-30 | |||||
学位授与年度 | ||||||
2009 | ||||||
要旨 | ||||||
内容記述タイプ | Other | |||||
内容記述 | Studies on π-electronic molecules have been one of the important subjects in<br />organic electronics and optoelectronics. Introduction of metal modules to conjugated<br />molecules plays an important role in expanding the diversity of supramolecular self-<br />assembly. For example, properties of metal ions such as magnetism, redox, and<br />photochemical activities may be transcribed on the supramolecules. This thesis<br />reports a general strategy for the integration of metal species to π-electronic<br />compounds via conjugation. It demonstrates the first synthesis of conjugated<br />multinuclear metallo complexes and their assemblies to form two-dimensional<br />molecular tapes and sheets with unique electronic and photo functionalities. In<br />relation to these hole-transporting supermolecules, this thesis reports a new kind of n-<br />type conducting molecules with robust thermal stability, high processability, and large<br />electron mobility. These unique properties are unprecedented and highly correlated<br />with their well-defined supramolecular architectures.<br /> Along this line, I reports the development of novel functional macromolecules<br />via topological design, by focusing on the creation of a new class two-dimensional<br />polymers and the finding of light-harvesting effect of conjugated microporous<br />polymers. Exploration of functional macromolecules is one of the interesting and<br />central topics in chemistry, physics, and molecular science. Especially, π-electronic<br />macromolecules are indispensable in molecular devices such as biosensors, light-<br />emitting diodes, and plastic solar cells. Their capabilities of triggering emission,<br />photoinduced energy/electron transfers, and charge carrier transportation are key<br />factors that vitalize device performance. Various 1D conjugated polymers have been<br />developed for these purposes, while the molecular design of 3D conjugated polymers<br />has led to unique dendritic scaffolds for cascade energy transduction. To access 2D<br />polymeric architecture, elaborate modifications of 1D conjugated polymers have led<br /> to findings of 2D anisotropic monolayers and thin films by SAM, LB, and LBL<br /> techniques. Clearly, a covalent 2D polymer assures a robust and shape-persistent<br />polymer network with permanent order in its building blocks. Synthesis of such<br />covalent 2D polymers has been heavily pursed since they are expected to open<br />entirely new vistas for future science and technology. However, the existence of<br /> covalent 2D polymers has not yet been proved and the development of a realistic way<br />to create such polymers remains a major challenge. This thesis describes the first<br /> example of the synthesis of a covalent two-dimensional (2D) conjugated polymer,<br />which is a completely new class of polymer.<br /> As summarized in the above, my thesis consists of the design, synthesis, and<br />functional exploration of supermolecules and macromolecules, with an emphasis on<br />the development of novel π-electronic nanoarchitectures.<br /><br /><b>(1)The Noncovalent Assembly of Benzene-Bridged Metallosalphen Dimer:<br />Photoconductive Tapes with Large Carrier Mobility and Spatially Distinctive<br />Conduction Anisotropy<br /></b> In photoconduction, photo-generated charge carriers move to electrodes and<br/>produce electric current. Studies on such photo-responsive molecules have been an<br />important part of progress in the field of solar energy conversion. Single crystals of<br />certain π-conjugated molecules, <i>e.g.,</i> arenes, have been reported to become<br />photoconductive as a result of exciton migration and charge separation at the<br />molecule-electrode interface. However, small arenes absorb photons only in the<br />ultraviolet region, while large arenes with absorption bands extending to the visible<br />region require complicated synthesis along with tedious purification and are difficult<br />to process. Moreover, the undesirable photoinduced dimerization and bleaching of<br />arenes deter their application to optoelectronics. During a study on the assembly of<br />conjugated multinuclear metallocomplexes, I serendipitously discovered that these π-<br />electronic metallo-conjugates are photo-responsive, robust against irradiation and may<br />avoid the above drawbacks.In the first part, I describes a newly synthesized benzene-<br />bridged metallosalphen dimer tailored with alphatic chains, which is demonstrated for<br />the solution-processed assembly of a π-electronic tape. The tape is unique in that it<br />shows a large intrinsic carrier mobility, is spatially anisotropic in conduction, forms<br /><i>p-</i> or </i>n-</i>type semiconductors tunable upon doping. I emphasizes that the tape is highly<br />responsive to visible light irradiation, triggers prominent photocurrent generation,<br />shows on/off ratios as high as 9.0 × 10<sup>4</sup> and is capable of repeated on-off switching<br />without deterioration. Molecular design of bridged dinuclear metallocomplexes has<br />led to the findings of unusual physical properties and utilities such as catalysts,<br />mimicry for biological enzymes, molecular magnets, building blocks for coordination<br />polymers and MOFs. However, photo functions have been unexplored to date.<br /><br /><b>(2) Noncovalently Netted, Photoconductive Sheets with Extremely High Carrier<br />Mobility and Conduction Anisotropy from Triphenylene-Fused Metal Trigon<br />Conjugates<br /></b> Studies on conjugated molecules have been one of the central subjects in organic<br/>electronics and optoelectronics. Introduction of metal modules to conjugated<br />molecules plays an important role in expanding the diversity of supramolecular self-<br />assembly. For example, properties of metal ions such as magnetism, redox, and<br />photochemical activities may be transcribed on the supramolecules. In this context,<br />triphenylene, a typical conjugated planar molecule, is an intriguing motif for such a<br />purpose due to its utility in supramolecular assembly. However, up to date, metal-<br />containing triphenylene derivatives have been limited to only thio-ligated bismuth and<br />silver crystalline solids. In relation to the first part, here, I reports the first example of<br />triphenylene-fused metal trigon conjugates, where multinuclear metal sites are<br />connected to one another via conjugation with triphenylene core. The metal trigon<br />upon self-assembly forms well-defined 2D sheet, which harvests a wide range of<br />photons, converts them to bright emission, and allows exciton migration. Moreover, <br />the 2D sheet is semiconducting with a high carrier mobility and capable of repetitive<br /> on-off current switching at room temperature. The noncovalent 2D sheet is<br /> photoconductive to exhibit a quick response to visible light irradiation with large<br />on/off ratio. Spatial anisotropy in conductivity reveals that the sheet assembly favors a<br />conduction path perpendicular to the stacked sheets other than the one along the sheet<br />planes. These characters are unique and clearly originate from the highly ordered<br />molecular structure of the noncovalent sheet assembly.<br /><br /><b>(3)Pyrene-Fused Phenazine Bisimides as Robust, Solution Processable and<br />Chemically Addressable n-Channel Organic Semiconductors<br /></b> Organic semiconductors have attracted great interests in relation to their utilities<br />in optoelectronics and molecular electronics. In contrast to rich varieties of <i>p-</i>type<br />semiconductor, <i>n-</i>type organic semiconductor has been very limited in numbers to<br />certain electron-withdrawing π-conjugation systems including perfluorinated aromatic<br />compounds, heteroaromatic compounds, and fullerene derivatives. Due to electronic<br />deficient nature, n-type organic semiconductors are usually unstable and air sensitive<br />in conducting condition. Recently, bisimides with aromatic cores such as anthracene,<br />naphthalene, perylene, and tetrathiafulvalene moieties have been reported to function<br />as n-type semiconductor, which allows supramolecular self-assembly upon tailoring<br />at bisimide terminals with alkyl chains to fabricate various nanostructured devices.<br />Very recently, phenazine compounds have been demonstrated to be <i>n-</i>type<br />semiconductor with high carrier mobility due to the presence of electron-withdrawing<br />imine units. In this part, I report a molecular system combining three structural<br />parameters (1) bisimide terminals, (2) phenazine linkages, and (3) an extended π-<br />conjugation pyrene core, <i>i.e.,</i> pyrene-fused phenazine bisimide as a novel <i>n-</i>type<br />organic semiconductor. I highlights that such a topological design allows a multiple<br />combination of high thermal and air stability, ordered crystalline packing together<br />with facile solution processability. Moreover, protonation of phenazine units leads to<br />the generation of quadruple cationic bisimide, thus converting the conjugated neutral<br />skeleton to positively charged backbone. We found that bisimide and cationic<br />bisimide are n-type semiconducting with the largest charge carrier mobility of 4.1<br />cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup> and capable of stable repetitive on/off current switching in ambient<br />condition.<br /><br /><b>(4) Synthesis of Covalent Two-Dimensional Polymers Using a Topological Approach</b><br /> Conjugated polymers are commonly used for a wide variety of applications.<br />Extensive research has led to the realization of one-dimensional linear and three-<br />dimensional hyperbranched and dendritic conjugated polymers. Despite tremendous<br />efforts, a fully-characterized covalent two-dimensional conjugated polymer has not<br />yet been achieved and its creation remains a substantial challenge. In this part I<br />reports the synthesis of a two-dimensional conjugated poly(para-phenylene), by<br />covalently 'knitting' one-dimensional linear conjugated chains, based on a specific<br />topological two-dimensional cross-coupling polycondensation reaction. This 2D<br />polymer is crystalline and consists of flat square sheets with very clear and smooth<br />edges. It holds extremely dense interwoven longitudinal and latitudinal straight chains<br />of 6.6 × 10<sup>6</sup> cubic micrometer and possesses persistent, long-range, periodic<br />repeating-unit order. Electronic experiments and transient conductivity measurements<br />predict that two-dimensional conjugated polymers would exhibit completely novel<br />properties when used in molecular electronics and optoelectronics.<br /><br /><b>(5) Light-Harvesting Conjugated Microporous Polymers: Spatial Confinement<br />and Inner Surface-Interfered Energy Transduction</b><br /> Conjugated microporous polymers (CMPs) are amorphous polymers with<br />conjugated framework and inherent three-dimensional porous structure. Owing to their<br />unique pore sizes which could be tuned through molecular design, CMPs serve<br />as a bridge between zeolites and MOFs/COFs. However, most studies to date have <br />mainly focused on the gas storage and separation properties. I envisioned that the<br />highly dense π-electronic components of CMPs framework could serve as antennae<br />for collecting photons, while the well-defined inner pores could embed and spatially<br />confine energy-accepting counterparts, thus leading to the fabrication of a<br />supramolecular system for energy transduction mediated by the large inner surface of<br />CMPs. In the last part of this thesis, the author reports the first example of light-<br />harvesting CMPs, which consist of microporous polyphenylene framework as<br />antennae and coumarin 6 noncovalently encapsulated within the pore as energy-<br />accepting pool. The CMP-based light-harvesting system not only allows the creation<br />of a novel noncovalent energy donor-acceptor array but much importantly makes it<br />possible a directional pinpoint energy transfer from the framework to the energy<br />converter. These characters together with a large inner surface facilitate the energy<br />transduction process and result in an almost 100% energy transfer quantum eficiency.<br />These unique properties constitue an important step to the utility of CMPs in sensing<br />and optoelectronics.<br /> Exploration of functional supramolecular and macromolecular nanoarchitectures<br />is a subject that has a high probability to lead to the development of new materials. In<br />summary, the author has developed a series of novel π-electronic supermolecules and<br />macromolecules. The author designed and synthesized a series of new π-electronic<br />multinuclear metallo conjugates and n-type conjugated molecules and succeeded in<br />the construction of π-electronic two-dimensional assemblies. By using topological<br />molecular design, a new class of polymers, i.e., covalent two-dimensional polymer<br />was created. By exploration of the porous channel, a novel light-harvesting antenna<br />based on conjugated microporous polymers was established. These π-electronic<br />organic architectures show unique photo and electrical functions that clearly originate<br />from their highly ordered structures and thus open a new way to molecular<br />optoelectronics and electronics. | |||||
所蔵 | ||||||
値 | 有 |