高分子　Vol.71　No.9　2022年9月

高分子　Vol.71　No.9

特集　凝集誘起○○：集めてもらえるステキな特典

展望　COVER STORY: Highlight Reviews

凝集誘起発光（AIE）の原理と未来
Principles of Aggregation - Induced Emission

小西玄一
Gen-ichi KONISHI

＜要旨＞溶液中で無蛍光で、固体状態で強発光する凝集誘起発光（AIE）色素は、一般的な蛍光色素と真逆の性質であり、21世紀になって概念が提唱され、分析化学、刺激応答材料などへの応用が盛んである。AIE色素の分子構造と発光メカニズムを解説するとともに、欲しい機能をもつ蛍光色素の合理的設計に向けた取り組みについても紹介する。
Keywords: Aggregation-Induced Emission / Fluorescence Dye / Photochemistry / Organic Light-Emitting Materials / Bio-Imaging / Analytical Chemistry / Stimuli-Responsive Materials

ページトップへ▲

集積発光性白金（Ⅱ）錯体－集めて並べて発光色を自在に制御
Control of Assembly-Induced Luminescence for Platinum(II) Complexes

加藤　昌子
Masako KATO

＜要旨＞平面四配位型の白金（Ⅱ）錯体は、積層して白金間に電子的な相互作用が生じると明瞭な発色や発光を示す。その性質は集積状態を鋭敏に反映して変化するため、超分子形成ダイナミクスの追跡や環境のモニターに適用できる。また、集積性を精密に制御することにより、多彩な発光色の実現や外部刺激応答性をもつクロミック錯体の構築ができる。
Keywords: Lumienscence / Platinum(II) Complex / Soft Crystal / Assembly / Vapochromism / Chromic Complex / Phase Transition

ページトップへ▲

凝集誘起遅延蛍光
Aggregation-Induced Delayed Fluorescence

安田　琢麿
Takuma YASUDA

＜要旨＞遅延蛍光を発する有機発光材料は、スピン多重度の異なる励起状態をとり得ることから従来の蛍光材料と異なる光物理的挙動を示す。分子凝集にともなって生じる濃度消光に抗って、凝集系ならではのユニークな光機能を引き出せないものか？　本稿では、分子凝集系で特異な発光特性を発現する遅延蛍光材料について紹介する。
Keywords: Aggregation / Concentration Quenching / Delayed Fluorescence / Exciton / Mechanochromic Luminescence / Organic Light-Emitting Diodes / Triplet

ページトップへ▲

トピックス　COVER STORY: Topics and Products

有機色素分子の凝集で誘起される光触媒活性
Photocatalytic Activity Induced by Self-Assembly of Organic Dyes

重光　孟・木田　敏之
Hajime SHIGEMITSU, Toshiyuki KIDA

＜要旨＞ Photocatalysts are essential materials for artificial photosynthesis. Herein, we introduce supramolecular photocatalysts consisting of hydrophilic organic dyes. The organic dyes without photocatalytic properties in the monomer state acquired this property by self-assembly owing to the formation of the charge separated state. The supramolecular photocatalysts are applied to hydrogen evolution and photooxidation reactions in water, and photodynamic therapy.
Keywords: Supramolecular Assembly / Photocatalyst / Hydrogen Evolution / Photooxidation / Photodynamic Therapy / Water

ページトップへ▲

液液界面での凝集誘起発光メカニズムと応用
Mechanism and Potential Applications of Aggregation-Induced Emission at Liquid-Liquid Interfaces

永谷　広久
Hirohisa NAGATANI

＜要旨＞ An interface between two immiscible electrolyte solutions (ITIES) has been utilized as a simple model of biomembrane surface to evaluate mass transport process and pharmacokinetics. Various species indicate self-aggregation features at ITIES, where the extent of aggregation of ionic species can reversibly be controlled by applying external potential. The potential-driven aggregation accompanied by a colorimetric response is favorable for bioimaging applications since the membrane potential of the living cell plays a crucial role in physiological processes. Most of the fluorescent dyes used in biochemical applications, however, exhibit emission properties in the aggregation-caused quenching (ACQ) mechanism, and this restricts their usefulness. In this article, the fundamental mechanism of transfer and adsorption of ionic dyes at ITIES under electrochemical control are described briefly. The recent findings on aggregation induced emission (AIE) of water-soluble tetraphenylethene derivatives at ITIES and at a phospholipid-adsorbed biomimetic interface will also be discussed in terms of its potential applications in spectrophotometric characterization of bio-tissues.
Keywords: Liquid-Liquid Interface / Ion Transfer / Adsorption / Aggregation Induced Emission

ページトップへ▲

ボロン酸の反応性を利用した凝集誘起発光型超分子
Boronate Supramolecules with Aggregation-Induced Emission Properties

久保　由治
Yuji KUBO

＜要旨＞ Molecular self-organization is one of the most promising methods to create nano- or microscopic structures in supramolecular chemistry. Current interest for preparation of functional solids hierarchically built up by using organic molecules have motivated chemists to use aggregation-induced emission (AIE) molecules that serve as efficient building blocks for endowing self-organized molecular systems with luminescent properties. Here, our successful examples such as AIE-active boronate nanoparticles and chemometrics-coupled chiral sensing using AIE boronate ensembles are presented. In the former, making use of facile dye-grafting at the surface of boronate particles, multi-color emission, involving white-light, was attained through Fröster resonance energy transfer process. In the latter case, two types of boronic acid-appended D-π-A cyanostilbenes were synthesized and produce chiral ensembles by dehydration with tartaric acid. Fingerprint-like emission response to chiral analytes is suitable for chiral sensing with linear discriminant analysis and artificial neural network. Well-tailored combination of boronate supramolecules and AIE function is discussed from standpoint of developing emissive nanomaterials.
Keywords: Aggregation-Induced Emission / Supramolecules / Dynamic Covalent Bond / Boronic Acid / Tetraphenylethylene / Cyanostilbene / Chiral Sensing / Chemometrics

ページトップへ▲

湾曲型三脚巴状クマリン色素のAIE特性
AIE Characteristics of Distorted Triskelion-Shaped Coumarin Dyes

上田　将史
Masafumi UEDA

＜要旨＞ This study reports the synthesis and properties of twisted triskelion-shaped AIE-gen bearing three coumarin units (1). X-ray crystallography revealed that 1 adopts a distorted and propeller-shaped geometry. Furthermore, compound 1 has two molecular π-surfaces with differing electrostatic potentials as with Janus-type molecules. Two enantiomers consisting of right-handed PPP-1 and left-handed MMM-1 existed as racemic mixture in the crystal structure. Theoretical calculation suggests that the ΔG^‡ in this molecular inversion between PPP-1 and MMM-1 was 9.0 kcal/mol. Therefore, compound 1 undergoes its helical inversion with ease. Interestingly, this twisted framework bearing coumarin dye formed nanoaggregates in THF/H₂O. The particle size was ca. 190～295 nm. Compound 1 exhibits favorable aggregation-induced emission enhancement based on the distorted geometry. This supports that helical inversion of 1 is inhibited in the nanoaggregates, as the result, non-radiation deactivation process due to molecular vibration is restricted by fixed molecular conformation.
Keywords: Aggregation-Induced Emission Enhancement / Coumarin / Distorted Triskelion / Janus-Type Structure / Molecular Helical Inversion

ページトップへ▲

グローイングポリマー　Polymer Science and I: A Personal Account

挑戦し続けること
Let’s Keep Trying!

宮田　真理
Mari MIYATA

＜要旨＞ Research that pursues unknown things and truths is fascinating, and I want to be a person who can convey the joy of research to students and those around them. I would like to continue to take on challenges without forgetting to thank the many people involved in my research activities.

ページトップへ▲

高分子科学最近の進歩　Front-Line Polymer Science

レドックスポリマーを用いた酵素型バイオ燃料電池
Enzymatic Biofuel Cells Using Redox Polymers

田巻　孝敬
Takanori TAMAKI

＜要旨＞ Enzymatic biofuel cells utilize the ability of enzymes to oxidize or reduce various substances to convert the chemical energy of fuels into electricity. One important topic in enzymatic biofuel cells has been the electron transfer between enzymes and electrodes. Except for enzymes that undergo direct electron transfer, redox mediators shuttle electrons between enzymes and electrodes. When mediators are immobilized to polymers, creating so-called redox polymers, the apparent diffusion coefficient of mediators decreases. Thus, the apparent diffusion of mediators becomes the rate-limiting step in the electrodes with thick redox polymer films. The rational design of electrodes by combining high-surface-area electrodes and thin redox polymer films is required to fully utilize the high intrinsic activity of enzymes. Recent advances in the design methodology for electrodes of enzymatic biofuel cells using redox polymers and the application as implantable and wearable devices are introduced in this article.
Keywords: Biofuel Cell / Redox Polymer / Mediator / Enzyme / Graft Polymerization / Carbon / Surface Modification

ページトップへ▲