Small Reorganization Energy Research Articles

Structural, Electronic, and Thermochemical Preference for Multi‐PCET Reactivity of Ruthenium(II)‐Amine and Ruthenium(IV)‐Amido Complexes

AbstractThe multiredox reactivity of bioinorganic cofactors is often coupled to proton transfers. Here we investigate the structural, thermochemical, and electronic structure of ruthenium‐amino/amido complexes with multi‐ proton‐coupled electron transfer reactivity. The bis(amino)ruthenium(II) and bis(amido)ruthenium(IV) complexes [RuII(bpy)(en*)2]2+ (RuII‐H0) and [RuIV(bpy)(en*‐H2)2]2+ (RuIV‐H2) interconvert reversibly with the transfer of 2e−/2H+ (bpy=2,2’‐bipyridine, en*=2,3‐diamino‐2,3‐dimethylbutane). X‐ray structures allow correlations between the structural and electronic parameters, and the thermochemical data of the 2e−/2H+ multi‐square grid scheme. Redox potentials, acidity constants and DFT calculations reveal potential intermediates implicated in 2e−/2H+ reactivity with organic reagents in non‐protic solvents, which shows a strong inverted redox potential favoring 2e−/2H+ transfer. This is suggested to be an attractive system for potential one‐step (concerted) transfer of 2e−and 2H+ due to the small changes of the pseudo‐octahedral geometries and the absence of charge change, indicating a relatively small overall reorganization energy.

Radical Mechanism of Ir III /Ni II -Metallaphotoredox-Catalyzed C(sp 3 )–H Functionalization Triggered by Proton-Coupled Electron Transfer: Theoretical Insight

Photoredox catalysis can be induced to activate organic substrates or to modulate the oxidation state of transition-metal catalysts via unique single-electron transfer processes, so as to achieve c...

Design of sensitizer with suitable frontier molecular orbital via substitution on starburst triphenylamine derivative.

Herein, a series of organic molecules were designed through locating different substituents on the compound (WD8-c-1) to develop their performances used as the sensitizers in the field of dye-sensitized solar cells. The geometry and relevant electronic properties of WD8-c-1 and its derivatives were simulated at the B3LYP/6-31G(d,p) level. The absorption spectra were calculated using the TD-PBE0/6-31+G(d,p) method. These calculated results show that the type and position of the substituents strongly affected the distributions of frontier molecular orbitals and the energy gaps for the WD8-c-1-derived molecules. The reorganization energies results reveal that their hole charge transfer rates are higher than that of the representative hole transport material. Moreover, the mobility of the representative WD8-c-1 derivative also has been simulated. The starburst triphenylamine with suitable substituent has the more suitable FMO energy to match those of TiO2, broad absorption region, smaller reorganization energies, and high hole mobility.

Unraveling the Mechanism of Near-Infrared Thermally Activated Delayed Fluorescence of TPA-Based Molecules: Effect of Hydrogen Bond Steric Hindrance.

A recently synthesized novel molecule (named CAT-1) exhibits intriguing near-infrared (NIR) thermally activated delayed fluorescence (TADF) close to 1000 nm wavelength; however, the mechanism behind these intrinsic properties is not fully understood. Herein, we unravel that the fluorescence emission spectrum with a broad wavelength range (770-950 nm) of CAT-1 is primarily induced by hydrogen bond steric hindrance based on density functional theory and Marcus theory. It is found that the hydrogen bond steric hindrance plays a critical role in inhibiting the twist of the configuration of different excited states, which leads to the minor driving force for fast electron trapping between the excited states, as well as small internal reorganization energy caused by less changed geometric configuration. Furthermore, such steric hindrance will cause a more distorted plane, resulting in a less favorable electron delocalization. A faster reverse intersystem crossing (RISC) rate is then obtained due to the nearly unchanged conformation between excited states caused by steric hindrance, although the spin-orbit coupling is small. Consequently, the NIR TADF with a longer wavelength can be emitted in CAT-1. This work shows that the hydrogen bond steric hindrance can fine-tune the electronic interactions of the donor and acceptor units to control the TADF.

A Quantum Chemical Screening of Two Imidazole-Chalcone Hybrid Ligands and Their Pd, Pt and Zn Complexes for Charge Transport and Nonlinear Optical (NLO) Properties: A DFT Study

A quantum chemical screening of two imidazole-based chalcone ligands: 2- [1-(3-(1H-imidazol-1-yl)propylimino)-3-(phenylallyl)]phenol and 2-[1-(3-(1H- imidazol-1-yl)propylimino)-3-4-nitrophenylallyl]phenol (hereinafter referred to as HL1 and HL2 respectively) and their Pd, Pt and Zn chelates for charge transport and nonlinear optical (NLO) properties, is reported via dispersion- corrected density functional theory (DFT-D3) and time-dependent DFT (TD- DFT) methods. From our results, Pd and Pt complexes have been observed to show excellent hole-transport properties, owing to their very small reorganization energies. The light extraction efficiency of the HL1-Pt complex was deduced to be particularly impressive, thus suitable for the manufacture of hole transport layer in violet light emitting diodes (LEDs). Moreover, redox potentials and chemical stability studies have enabled us to validate the greater stability in moisture (towards oxidation), of HL2 complexes compared to their HL1 counterparts. The first and second hyperpolarizabilities of both ligands and their complexes have been found to be outstandingly higher than those of the push-pull prototypical, para-nitroaniline by factors of up to 12 in the case of HL2. These compounds, with the exception of the HL2-Pt complex, are thus interesting candidates having wide transparency tradeoffs for NLO efficiency in the manufacture of optoelectronic and photonic devices capable of second and third-order NLO response. Finally, metal chelation has been established to enhance the NLO response of all the chalcone-based imidazole ligands investigated as a result of metal-ligand charge transfer and ligand- metal charge transfer electronic transitions identified in the resulting complexes with the exception of the zinc complexes.

Efficient tuning of triphenylamine-based donor materials for high-efficiency organic solar cells

Small molecular donors (SMDs) manifest promising photovoltaic performance and rapid progress in solar cells community. Herein, we investigate high-performance triphenylamine (TPA) small molecular donors for solar cells applications. We specifically designed four donor molecules (D1–D4) with a strong donor moiety of triphenylamine (TPA) linked to four different end-capped units. The structure-property relationship and effects of end-capped units on D1-D4 are theoretically calculated and compared with reference molecule R. DFT and TD-DFT approach have been employed and assessments of photophysical characteristics, frontier molecular orbitals (FMOs), reorganization energies, density of state (DOS) and overlap population density of state (OPDOS), open-circuit voltages (Voc), transition density matrix (TDMs), surfaces and charge transfer analysis were conducted. In comparison to synthesized reference molecule R, designed D1-D4 molecules show significant and comparable optoelectronic properties. The D3 designed molecule is proven as the best candidate for solar cells applications than all other due to its promising photovoltaic properties involving the lowest band gap (3.329 eV) and excitation energy (3.094 eV), small reorganization energies for electron (λe = 0.110 eV) and hole (λh = 0.055 eV), low binding energy (Eb = 0.221 eV), highest λmax values 396.69 nm, 400.63 nm both in gas and solvent form, respectively. This theoretical designed model confirms that the end-capped unit modifications proves an efficient alternative solution in achieving the desired optoelectronic properties. Therefore, D1-D4 designed molecules are outstanding and highly recommended to experimentalists for developments of highly efficient solar cells devices in future.

Elucidating the Magnitude of Internal Reorganization Energy of Molecular Excited States from the Perspective of Transition Density.

Quantifying vibronic couplings in molecular excited states is crucial for the elucidation of a broad range of photophysical phenomena. In this study, we compare different theoretical approaches for the calculation of reorganization energy, a measure of vibronic coupling strength, and provide a rigorous derivation to show that molecular transition density characterizing electron-hole excitation could be used to quantify the magnitude of reorganization energy. The theory enables a descriptor based on molecular-orbital coefficients and atomic transition densities to quantify the magnitude of reorganization energies in molecular excited states. Applying the approach to low-lying excited states of polyacenes, we demonstrate that transition density distribution explains the difference in the magnitude of the reorganization energy of different excited states. Furthermore, to clarify the applicability of the transition density descriptor in molecular design for small-reorganization energy molecules, we investigate a broad range of molecular chromophores to show the effectiveness of the proposed theory. With this perspective on the relationship between reorganization energy and transition density, we successfully provide a quantitative rule to identify π-conjugated systems with small reorganization energy in the excited state, which should be useful for the development of novel optoelectronic materials.

Carbonyl-Terminated Quinoidal Oligothiophenes as p-Type Organic Semiconductors.

A series of quinoidal oligothiophenes terminated with carbonyl groups (nTDs, n = 2–4) are studied as p-type organic semiconductors for the active materials in organic field-effect transistors (OFETs) both by the theoretical and experimental approaches. The theoretical calculations clearly show their high-lying highest occupied molecular orbital (HOMO) energy levels (EHOMOs), small reorganization energies for hole transport (λholes), and large contribution of sulfur atoms to HOMOs, all of which are desirable for p-type organic semiconductors. Thus, we synthesized nTDs from the corresponding aromatic oligothiophene precursors and then evaluated their physicochemical properties and structural properties. These experimental evaluations of nTDs nicely proved the theoretical predictions, and the largest 4TDs in the series (4,4′′′-dihexyl- and 3′,4,4″,4′′′-tetrahexyl-5H,5′′′H-[2,2′:5′,2″:5″,2′′′-quaterthiophene]-5,5′′′-dione) can afford solution-processed OFETs showing unipolar p-type behaviors and hole mobility as high as 0.026 cm2 V−1 s−1.

Real-Time Observation of the Diffusion Mechanism Progression from Liquid to Solid State of Transition Metal Complexes

Copper complexes have recently shown remarkable performance upon conversion from liquid-based to solid-state hole transport materials (HTMs) in mesoscopic solar cells; however, the diffusion mechanism is not clear. In this work, we apply an in situ solidification analysis of the charge diffusion and find that the dominant mechanism of [Cu(dmbpy)2]2+/+ (dmbpy = 6,6′-dimethyl-2,2′-bipyridine) changes from ionic to electronic diffusion. Through use of the modified Dahms–Luff equation, a fast self-exchange rate constant of hole-hopping in the HTM of 8.3 × 108 (±5 × 107) M–1 s–1 is calculated, which indicates a small reorganization energy of 0.47 eV. These results introduce a new methodology to analyze the transport mechanism of solids, reveal the mechanism of charge transport in molecular-based HTMs, and offer insight into ways to control the flow of charge in optoelectronic systems.

Axially Chiral Spiro-Conjugated Carbon-Bridged p-Phenylenevinylene Congeners: Synthetic Design and Materials Properties

Spiro-conjugated systems are attracting considerable interest for their chiroptical properties and because of their compact structure the small reorganization energy upon electronic excitation or ionization. We report here a modular and convergent synthesis of axially chiral spiro-conjugated carbon-bridged p-phenylenevinylenes (spiro-CPVs) in a racemic and optically active form where two carbon-bridged p-phenylenevinylene molecules are connected by a spiro carbon atom. Our synthetic design focuses on the C2 symmetry of the spiro-CPV molecules, relying on coupling of two 3-lithio-2-arylindene molecules on a carbon monooxide molecule that serves as the spiro carbon center in the target molecule. We prepared derivatives including those possessing phenol groups that facilitate optical resolution and also serve as a platform for the synthesis of a variety of optically active derivatives, which exhibit circularly polarized photoluminescence with high fluorescence quantum yields, large dissymmetry factors, and high photostability. For example, a bis(phenylethynyl) derivative exhibited a fluorescence quantum yield of 0.99 and a dissymmetry factor in luminescence of |glum| = 2.7 × 10-4, values highest among and comparable to those of reported CPL compounds, respectively. A tetrakis-diarylamine derivative shows hole mobility (μh = 3.84 × 10-5 cm2 V-1 s-1; space charge-limited current measurement of a spin-coated film) comparable to that of a popularly used hole-transporting material, spiro-OMeTAD (μh = 2.6 × 10-5 cm2 V-1 s-1), as well as high thermal and phase stability (T5d = 382 °C, Tg = 171 °C).

Acceptor/Donor End Capped Phenylene-Thiophene Co-oligomers Toward Efficiencies Organic Electronic Devices

In this paper, geometrical (in ground and excited states), electronic, optical and charge transfer properties, (ionization potentials (IP), electron affinities (EA) and HOMO-LUMO gaps (ΔEH-L), as well as the lowest excitation energies (Eex) and reorganization energies) of the phenylene-tiophene oligomers are studied by the density functional theory (DFT) and Time-dependent DFT approaches. Based on the density functional theory (DFT/B3LYP and CAM –B3LYP functional with 6-31G (d,p) basis set), we will highlight the effect of terminal acceptor/donor (CN, NO2, and CF3) /OCH3, N(CH3)2 substituents on thiophene-phenylene derivatives. The excited state indicates more planar structures of the co-oligomers, which leads to a decrease in the (HOMO-LUMO) gap compared with the ground state, especially when the acceptor character increases. Furthermore, the vinyl spacer and cyanide ((–CN) functional group (Compound C8) stabilize the LUMO levels of energy and improve the transport properties of the thiophene-phenylene derivatives. Comparing with the donor groups, the results show that the electron withdrawing substituents are remarkable on the energy levels of the frontier molecular orbitals, and on the transport charge proprieties in these co-oligomers. Thus, the LUMO energy levels become more stabilized for co-oligomers having more acceptor moieties and the HOMO–LUMO energy gap is reduced, therefore, the improvement of the conduction properties of these species is, then, observed. Moreover, the absorption spectra, computed in the presence or not of solvent at PCM model in chloroform, shows that the increase of acceptor character induces a red shift and important absorption intensity. The decrease injection barrier and smaller reorganization energies are revealing that our designed co-oligomers would be an efficient hole as well as electron transfer materials. The predicted values have shown that the designed derivatives would be efficient for the organic field effect transistors, photovoltaics and light emitters.

Synthesis and Characterization of Pyrano[3,2-C]Chromene Derivatives: Exploring Their Optoelectronic and Charge Transport Properties By First-Principles Approach

With the aim to enhance the charge transport, optoelectronic and semiconducting properties various multifunctional pyrano[3,2-c]chromene derivatives were synthesized and characterized. To shed light on the various properties of interests, the ground state geometries were optimized by Density Functional Theory (DFT). The effect of different substituents, e.g., thiophen-2-yl, 5-bromothiophen-2-yl, 1H-indol-3-yl, pyridin-3-yl, and benzo[d][1,3]dioxol-5-yl was studied on the structural stability, electronic properties, and absorption wavelengths by DFT and Time-Domain DFT (TDDFT). The experimental excitation energies were successfully reproduced at TD-PBE/6-31G** level in DMSO. The electron injection barrier, ionization potential, electron affinity and reorganization energies for hole and electron were calculated and compared systematically. The smaller electron reorganization energies of pyrano[3,2-c]chromene derivatives except indole substituted one are illuminating that these materials would be efficient to be used in n-type semiconductor devices.

Theoretical Studies of Bipolar Transport in CnBTBT-FmTCNQ Donor-Acceptor Cocrystals.

The development of crystals with bipolar transport characteristics is essential for high-performance organic field effect transistor (OFET) devices. In this work, we theoretically investigated the bipolar transport behaviors in CnBTBT-FmTCNQ cocrystals. It is found that bipolar transport can be realized in C8BTBT-TCNQ and C12BTBT-TCNQ cocrystals with room-temperature electron/hole mobility up to 1.8/0.75 and 2.5/1.8 cm2 V-1 s-1, respectively. The comparable electron- and hole-transfer integrals between the nearest-neighbor molecule pairs as well as the small hole reorganization energy of the TCNQ molecule are responsible for the balanced electron and hole mobilities. Moreover, because of the π-π stacking between neighboring molecules, all cocrystals show strong anisotropic transport characteristic for both electron and hole transport with the mobility along the π-π stacking direction much larger than those along the other two directions. This work provides the possibility of high-performance OFET engineering and also enriches the OFET families with bipolar transport characteristics.

Radiative and non-radiative exciton recombination rate constants in ZnSe clusters

Understanding the origin of photoluminescence intermittency and its correlation with microstructure is crucial for the design and preparation of quantum dots (QDs) with high fluorescence quantum yield. ZnSe clusters provide a typical model for studying the effect of their size, geometrical and electronic structures on their radiative and non-radiative process of II-VI QDs. The rate constants of radiative and non-radiative processes, kr and knr, of the (ZnSe)n clusters were computed by using first-principles calculations, Einstein spontaneous radiation theory and Fermi’s golden rule. The kr and knr variations with cluster size were analyzed in term of a number of quantities. Emission energy and reorganization energy were identified to play dominant roles in the determination of kr and knr for the studied clusters. Furthermore, a correlation between these two quantities and the geometric rigidity of the ZnSe clusters was revealed. The clusters with greater geometric rigidity tend to possess larger emission energy, and smaller reorganization energy. While radiative and non-radiative electron–hole recombination rates of the ZnSe clusters vary in a complicated way because of their diverse structures and prominent quantum size effect, our study highlights the correlation between recombination rate and cluster structure, which would be helpful for the design of QD materials with high fluorescence quantum yields.

Porphyrinoid–Fullerene Hybrids as Candidates in Artificial Photosynthetic Schemes

Natural photosynthesis inspired the scientific community to design and synthesize molecular assemblies that possess advanced light-harvesting and electron-transfer features. In this review, we present the preparation and the photophysical investigation of novel porphyrin–fullerene hybrids acting as artificial photosynthetic systems. Porphyrinoids stand as chlorophyll analogues and have emerged as suitable photosensitizers in supramolecular electron donor–acceptor hybrids. Fullerenes (C60) are versatile electron acceptors with small reorganization energy and low reduction potentials. The novel derivatives presented herein mimic the fundamental features of the photosynthetic reaction center, namely, light harvesting, charge separation, and charge transport. To this end, a comprehensive analysis on these key processes that occur in various porphyrin–fullerene entities is illustrated in this work.

Small Reorganization Energy for Ligand-Centered Electron-Transfer Reduction of Compound I to Compound II in a Heme Model Study

The electron-transfer (ET) processes from electron-donor substrates to oxoiron(IV) porphyrin π-cation-radical species (Cpd I) are key steps in their oxygenation reactions. Here, we have evaluated the rate constants of the outer-sphere ET reduction of Cpd I model complexes of meso-tetramesitylporphyrin (1) and 2,7,12,17-tetramesityl-3,8,13,18-tetramethylporphyrin (2) in light of the Marcus theory of ET to determine the ET reorganization energies (λ). The λ values of the ligand-centered ET reduction of Cpd I model complexes are much smaller than those of the metal-centered ET reduction of various oxoiron(IV) complexes. Moreover, the λ value of 1 is larger than that of 2, resulting from the difference in the nature of the a1u/a2u porphyrin π-cation-radical orbitals.

Theoretical insights on the comparison of champion dyes SM315 and C275 used for DSSCs reaching over 12% efficiency and the further optimization of C275.

Theoretical insights on the comparison between the champion dyes SM315 and C275 used for high-performance dye-sensitized solar cells (DSSCs) reaching over 12% efficiency with different electron donors only (porphyrin for SM315 and indenoperylene for C275) were explored for the first time. The intrinsic reasons for the significantly improved monochromatic photon-to-electric current conversion efficiency (IPCE) and open circuit voltage (Voc) of C275-based DSSCs over those of SM315 were revealed. According to our results, we find that the larger IPCE of C275 is attributed to its larger electronic coupling, smaller reorganization energy, reduced exciton binding energy and enhanced charge transfer character, all of which when combined lead to a larger electron injection efficiency. In addition, the larger Voc of C275 is due to a greater number of injected electrons, a smaller molecular volume and a smaller projected area, which lead to a more compact adsorption layer with a hindered charge recombination process. Thus, C275 is expected to have more potential to further optimize high-performance DSSCs. In view of the primary shortcoming of C275, which is its relatively narrow absorption spectrum, further optimization was made through structural modification using a series of heterocyclic anchoring groups. Using the same evaluation criteria, the theoretical screening of these dyes based on C275 is carried out. We find that indenoperylene dye with a barbituric acid (BA) anchoring group is a promising candidate for the experimental synthesis of high-performance DSSCs with improved Jsc, Voc and adsorption stability.

Highly Planar and Completely Insulated Oligothiophenes: Effects of π-Conjugation on Hopping Charge Transport.

Elucidating the nature of long-range intramolecular charge transport in π-conjugated molecules is of great importance for the development of organic electronic materials. However, the effects of the degree of π-conjugation on the hopping charge transport have not been experimentally explored so far owing to the lack of π-conjugated backbones with different conjugation degrees and several-nanometer lengths. Here we develop highly planar and completely insulated oligothiophenes between 0.85 and 9.64 nm in length. As compared to distorted oligothiophenes, single-molecule conductance measurements of the planar molecules show (i) a smaller activation energy and larger electrical conductance in the hopping transport regime and (ii) a shift in crossover between tunneling and hopping conduction toward a short molecular length. Theoretical calculations indicate that small reorganization energies and narrow energy gaps derived from the planar backbones result in these superior characteristics. This study reveals that the planarity of π-conjugation has significant advantages for hopping charge transport.

Design of a novel series of small molecule donors for application in organic solar cells

In an effort to study high-efficient electron donor materials for application in organic solar cells (OSC), density functional theory (DFT) calculations were performed to predict a variety of small molecules (SMs) with terminal acceptor-π bridge-central donor-π bridge-terminal acceptor (A-π-D-π-A) framework. An interesting A-π-D-π-A-type SM containing phenothiazine as D unit has been recently synthesized and applied to in the OSC. Motivated by this study, here, we have systematically predicted 10 SM donor materials based on the phenothiazine as the central D unit as well as several A and π units that have been used into materials representing excellent SC as well as charge transport characteristics. Then, the structural, electronic, and optical properties of the predicted SM donors have been investigated. The fundamental band gap energies, orbital spatial distributions, and intrinsic dipole moments were calculated using DFT while the optical band gap energies were obtained using time-dependent density functional theory (TD-DFT). Several SC properties of the predicted SMs were then computed and compared with the available experimental results of OSCs. Our suggested SMs represented the enhancement in the open circuit voltage (VOC) and charge transport properties which may lead to OSCs with improved power conversion efficiency (PCE) compared to the previously synthesized SMs. Moreover, small reorganization energies, large transfer integrals, and high intra-molecular coupling obtained from dense π-stacking give rise to increased electron mobility in the predicted SMs. However, this strategy can be helpful for further improving the performance of SMs in OSCs.

(Invited) Isomer Effects of Nanocarbons in Organic Solar Cells

Fullerene derivatives are excellent electron-accepting materials in bulk heterojunction (BHJ) organic photovoltaic (OPV) devices. The spherical cage structure of fullerenes endows the small reorganization energy in electron transfer, thereby yielding superior electron-accepting and electron-transporting properties. A typical fullerene derivative is [6,6]-phenyl-C61-butyric acid methyl ester ([60]PCBM). Its [70]fullerene analogue ([70]PCBM) has been frequently employed in high-performance OPVs over [60]PCBM because of better light-harvesting ability in the visible region and solubility in common organic solvents arising from the rugby ball-shape with lower symmetry. High power conversion efficiencies (PCEs) of 8–11% have been achieved using [70]PCBM in combination with various low-bandgap conjugated polymers. However, the lower symmetric C70 cage possesses four distinct types of double bonds (α, β, γ, and δ), and mono-addition to C70 generally leads to a mixture of regioisomer products. In fact, [70]PCBM prepared by a conventional method using 4-benzoylbutyrate tosylhydrazone and C70 contains α-type (80-90%) and β-type (10-20%) isomers. Despite its prevalence use in OPV devices, [70]PCBM is usually used as the isomer mixture, which veils the device performances depending on the individual isomers of [70]PCBM. In this talk, I will give an overview of the isomer effects of nanocarbons on BHJ OPV devices. In particular, I will focus on the comprehensive regioisomer and diastereomer separation effect of the most prevalent electron-acceptor ([70]PCBM) on the structures and photovoltaic properties of the blend films with a high-performance conjugated polymer (i.e., PffBT4T-2OD). In spite of the strong tendency of PffBT4T-2OD to form a bicontinuous structure with fullerene derivatives, one of the diastereomers of the β-isomer (β1-[70]PCBM) showed an extraordinary cohesion nature in the blend film, deteriorating the OPV device performance. OPV devices based on the other isomers (i.e., α-[70]PCBM (8.4%) and β2-[70]PCBM (8.4%)) rival or slightly surpass the device with the as-synthesized isomer mixture (mix-[70]PCBM, 8.2%) because of the existence of the poor performance β1-[70]PCBM. The results demonstrate the large impact of the substituent position and direction on a C70 surface on the photovoltaic properties. [1] S. Kitaura, K. Kurotobi, M. Sato, Y. Takano, T. Umeyama, and H. Imahori, Chem. Commun., 48, 8550-8552 (2012). [2] R. Tao, T. Umeyama,K. Kurotobi, and H. Imahori, ACS Appl. Mater. Interface, 6, 17313-17322 (2014). [3] R. Tao, T. Umeyama, T. Higashino, T. Koganezawa, and H. Imahori, Chem. Commun., 51, 8199-8388 (2015). [4] R. Tao, T. Umeyama, T. Higashino, T. Koganezawa and H. Imahori, ACS Appl. Mater. Interfaces, 7, 16676-16685 (2015). [5] T. Umeyama, T. Miyata, A. C. Jakowetz, S. Shibata, K. Kurotobi, T. Higashino, T. Koganezawa, M. Tsujimoto, , S. Gélinas, W. Matsuda, S. Seki, R. H. Friend, and H. Imahori, Chem. Sci., 8, 181-188 (2017). [6] T. Umeyama, S. Shibata, T. Miyata, K. Igarashi, T. Koganezawa, and H. Imahori, RSC Advance, 7, 45697-45704 (2017). [7] T. Umeyama, K. Igarashi, D. Sakamaki, S. Seki, and H. Imahori, Chem. Commun., 54, 405-408 (2018).