bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Regioisomers in Fullerene Derivatives on Photovoltaic Properties of Bulk Heterojunction Solar Cells
Authors: Imahori Hiroshi 
Published: February 2020

During the last decade, bulk heterojunction (BHJ) polymer solar cells (PSCs) revealed rapid progress and achieved a power conversion efficiency (PCE) of 6-10%, owing to the development of new high-performance low-bandgap polymers as electron donors. Meanwhile, although new electron-accepting materials for PSC devices habe been explored, [70]fullerene derivatives are still prevalent as electron acceptors. An important aspect of [70]fullerene derivatives, which is always neglected in PSC applications, is that as-prepared [70]fullerene mono-adducts consist of a mixture of regioisomers due to the lower symmetry of rugby-ball shaped C70 over spherical C60. As contrasted with C60, C70 has four distinct types of [6,6]-bonds (a-, b-, e-, and k-type bonds), and thereby [70]fullerene derivatives including a prevalent, high-performance [6,6]-phenyl-C71-butyric acid methyl ester ([70]PCBM) have been employed as a regioisomer mixture in BHJ PSC devices. Considering that the miscibility with conjugated polymers and the molecular arrangement of [70]fullerene derivatives in the active layer have a large impact on charge separation and charge-transporting properties, pristine isomers of [70]fullerene derivatives rather than the isomer mixtures would yield a more desirable donor-acceptor network toward highly efficient BHJ PSCs. Indeed, the regioisomer separations of fullerene bis-adducts have been demonstrated to exhibit positive effects on BHJPSCs. In this study, the regioisomers of [70]fullerene mono-adducts have been separated for the first time to evaluate the pure isomer effect on the photovoltaic properties. To assess the substitution position effect on C70 accurately, first we designed new dihydronaphthyl-substituted [70]fullerenes with two butoxycarbonyl groups ([70]NCMA) as a simplified system. The symmetrical dihydronaphthyl group was selected as the substituent to eliminate the plausible isomers such as enantiomers and diastereomers. Then, we have further extended this strategy to separate the regioisomers of a prevalent, high-performance [70]fullerene mono-adduct acceptor, [70]PCBM, for the first time.
[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., in press.
Improved Performance and Stability of Inverted Planar Perovskite Solar Cells Using New Fullerene Layers
Authors: Castro Edison , Zavala Gerardo , Fernandez Olivia , Echegoyen Luis 
Published: February 2020

The unique properties of organic-inorganic hybrid perovskite materials make them promising candidates for developing next-generation photovoltaic cells for commercial applications to compete with silicon solar cells. Inverted planar structure perovskite solar cells (PSCs), due to their low temperature precessing and lack of hysteretic problems, are attracting increased attention by researchers around the world. Fullerene derivatives are the most widely used electron transporting materials (ETMs) in inverted planar perovskite solar cells, especially [6,6]-phenyl-C61-butyric acid methylester (PC61BM), which exhibits very good performance. However, the influence of adducts on fullerene-based PSCs performance has not been fully explored to date. Here, new C60 and C70 fullerene derivatives were synthesized in high yields via Bingel reactions at room temperature and incorporated into CH3NH3PbI3 perovskite solar cells as electron transporting materials.

Figure 1. Synthesis of C60 and C70 fullerene derivatives via Bingel reaction.

Figure 1
(Invited) Sensitizing Charge Carrier Generation in a Conjugated Polymer Using a C70-Encapsulated Covalent Organic Polyhedron
Authors: Rumbles Garry 
Published: February 2020

This presentation will report on the photophysics of a covalent organic polyhedron molecule (COP-5) that contains two porphyrin molecules in the cage structure and with an encapsulated C70 molecule bound in its core. The photo-induced electron transfer processes in this structure create anomalously long-lived charge-transfer states that also respond in an unconventional fashion to the dielectric constant of the solvent. Preliminary results on using this complex to sensitize the production of long-lived charge carriers in a conjugated polymer will also be reported, where the carrier yields and kinetics are tracked using time-resolved microwave conductivity.
The purpose of this work is to gain a better understanding of the nature of charge transfer (CT) and charge-separated (CS) states in the production of carriers in conjugated polymers blended with fullerenes.
(Invited) Synthesis, Structures, and Properties of Stacked Antiaromatic Porphyrins
Authors: Shinokubo Hiroshi 
Published: February 2020

The stacking of antiaromatic compounds has not been well investigated. Theoretical calculations have proposed that staking of two antiaromatic systems lead to three-dimensional aromaticity, which results from mutual interactions between frontier orbitals of each π-system. However, there has been no experimental support for this interesting prediction.
Norcorrole is a ring-contracted porphyrin, which shows distinct antiaromatic character. We have discovered that diphenylnorcorrole Ni(II) adopts a triple-decker π–π stacked structure in the solid state. A significant reduction of antiaromaticity of the norcorrole skeleton was observed.

Figure 1
(Invited) Influence of Nano-Structuring of Substrate Materials on Local Structure of Ionic Liquid
Authors: Imanishi Akihito 
Published: February 2020

Ionic liquids (ILs) have attracted much attention as promising electrolytes for electrochemical devices due to their wide electrochemical window (stability) and negligible vaporization. For such applications, nanostructured electrodes have advantage on their large surface area leading to accumulation of large density energy at the interface. However, recent reports on IL/electrode interfaces revealed that quite strange structures can be formed and it is not clear how the interface forms and how it changes by forming the characteristic local structure. In this study, we investigated the local structure and physicochemical properties of the interfacial properties of nanostructured materials using XPS and electrochemical impedance spectroscopy (EIS).
Polystyrene beads were self-assembled in a close packed form on a gold substrate by dipping in polystyrene beads solution and rapid drying. Au electrodeposition on thus prepared surface followed by removal of the beads resulted in the fabrication of a nanostructured Au electrode with periodic 100 nm-sized Au dimples. Electrochemical behavior of a ferrocene dissolved ionic liquid (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl) amide (BMI-TFSA)) at the nanostructured Au electrode was investigated by EIS. It is obvious that the capacitance of the nanostructured electrode was smaller than that of the flat electrode in the whole potential range. This result suggests that the thickness of the electric double layer formed in the nano-sized dimple is thicker than that formed on the flat surface. The dimple size dependence on the capacitance will also be discussed.
On the other hand, it is an interesting subject to study how ILs and solutes behave in the nano-micro sized pore. We investigated the properties of IL(BMI-TFSA) and solute ions (Au3+, Ag+, Mg2+ etc.) confined in the porous silica whose diameter was 1.8 nm using XPS, IR and TEM. It was revealed that the molar ratio of all the ions existing in the pore is largely different from that in the bulk. Interestingly, the molar ratio of Au3+ to BMI+ (or TFSA-) was very large comparing with that of as prepared BMI-TFSA solution. The result of N-1s XPS spectra revealed that cation and anion of IL were organized in the nanopores. Such characteristic local structure in nanospace may affect the catalytic reaction in the pore.
(Invited) Pseudomorphic Transformation of Nanocrystals By Element Replacement
Authors: Teranishi Toshiharu 
Published: February 2020

Chemical conversion of inorganic nanocrystals (NCs) via element replacement reactions, such as ion exchange reactions and galvanic replacement reactions, can overcome the difficulties associated with controlling the size, shape, chemical composition and crystal structure in conventional syntheses. The retained shape of the parent-NCs in element replacement reactions provides an opportunity to obtain non-equilibrium unique structures and even new structures of inorganic NCs, these final structures being known as “pseudomorphs” [1-4]. Here I present the nano-pseudomorphic chemistry to give unique semiconductor [5] and metallic NCs [6].
[1] Saruyama, M.; So, Y.-G.; Kimoto, K.; Taguchi, S.; Kanemitsu, Y.; Teranishi, T. J. Am. Chem. Soc.
2011, 133, 17598.
[2] Kanehara, M.; Arakawa, H.; Honda, T.; Saruyama, M.; Teranishi, T. Chem. Eur. J.
2012, 18, 9230.
[3] Teranishi, T.; Samamoto, M. J. Phys. Chem. Lett.
2013, 4, 2867. (Perspective)
[4] Sakamoto, M.; Inoue, K.; Saruymama, M.; So, Y.-G.; Kimoto, K.; Okano, M.; Kanemitsu, Y.’ Teranishi, T. Chem. Sci.
2014, 5, 3881.
[5] Wu, H.-L.; Sato, R.; Yamaguchi, A.; Kimura, M.; Haruta, M.; Kurata, H.; Teranishi, T. Science
2016, 351, 1306.
[6] Sato, R.; Haruta, M.; Kurata, H.; Teranishi, T. to be submitted.
Earth Abundant Metal Corroles As Catalysts for Energy Relevant Processes
Authors: Gross Zeev , Mahammed Atif 
Published: February 2020

We have recently introduced corrole metal complexes (metallocorroles) as catalysts for various energy-relevant reactions. This includes those that are of prime importance for water splitting into its elements, the hydrogen and oxygen evolution reactions, and also the oxygen reduction reaction for fuel cells. A careful choice of substituents on the corrole ligand and the kind of metal ion (all earth abundant) chelated by them allows for lowering of the electrocatalytic overpotential, increasing reactivity, and controlling selectivity.
An arsenal of electrochemical and spectroscopic methodologies, which in the case of metallocorroles is very rich, was applied for acquiring highly valuable information about the mechanisms of action such as characterization of a cobalt-dioxgen intermediate.
REFERENCES
“Cobalt Corrole Catalyst for Efficient Hydrogen Evolution Reaction from H2O under Ambient Conditions: Reactivity, Spectroscopy and DFT Calculations”, Inorg. Chem.
2013, 52, 3381-3387.
"The Cobalt Corrole Catalyzed Hydrogen Evolution Reaction: Surprising Electronic Effects and Characterization of Key Reaction Intermediates" Chem. Commun.
2014, 50, 2725-2727.
"Metallocorroles as photocatalysts for driving endergonic reactions, exemplified by bromide to bromine conversion", Angew. Chem.
2015, 54, 12370 –12373.
"Metallocorroles as Non-Precious Metal Catalysts for Oxygen Reduction", Angew. Chem.
2015
, 54, 14080 –14084.
“Metallocorroles as Non-Precious Metal Electrocatalysts for Highly Efficient Oxygen Reduction in Alkaline Media" ChemCatChem
2016, 8, 2832-2837.
“Metallocorroles as Electrocatalysts for the Oxygen Reduction Reaction (ORR)", Israel J. Chem.
2016, 56, 756– 762.
“Dioxygen bound Cobalt Corroles”, Chem. Commun. 2017, in press.
A New Mode of Action for Porphyrins – Nonplanar Porphyrins As Organocatalysts
Authors: Senge Mathias O. 
Published: February 2020

Porphyrins are nature’s cofactors par excellence. Next to oxygen transport and storage, their role in electron transport and as photosynthetic pigments, they catalyze a multitude of chemical reactions. All these catalytic functions depend on the presence of a central metal which is intricately involved in the catalytic processes. Thus, all known catalytically active porphyrins are metalloporphyrins. However, we have discovered that, upon appropriate manipulation of the porphyrin macrocycle conformation, the core nitrogen atoms in free base porphyrins can be involved in catalysis as well.
Distorted porphyrins are able to activate small molecules via general base catalysis by participation of the imine groups or via hydrogen bonding catalysis involving the pyrrole units. To make the “active center” more accessible to substrates, the degree of outwards orientation of the pyrrole groups can be fine-tuned depending on the peripheral substitution pattern using peri-interactions or core substitution. Various distortion modes exist and saddle distorted porphyrins have been shown to have an increased basicity which qualifies these tetrapyrroles for catalytic screening. Additionally, it is possible to enhance the basicity via electronic modulation of the β- and meso-substituents through the introduction of electron-withdrawing groups. An extensive screening of a number of nonplanar porphyrins and substrates, as well as reaction conditions, has been used to evaluate the catalytic properties of planar and distorted porphyrins. Notably, certain free base porphyrins have been found to function as organocatalysts in Michael addition reactions indicating a new mode of catalytic action for porphyrins which does NOT require a central metal ion.
Synthesis and Properties of 10-Heterocorroles
Authors: Shinokubo Hiroshi 
Published: February 2020

The properties of porphyrinoids are substantially affected by their skeleton and structural factors. In particular, inclusion of heteroatoms into the p-conjugation circuit of porphyrinoids induces dramatic change of their electronic structures. Recently, 10-heterocorroles has regained the spotlight as promising candidates for novel building blocks of molecular materials as electronically tunable porphyrin analogues.
We have explored the synthesis and properties of meso-aryl type 10-aza-, 10-oxa-, 10-thia-, and 10-silacorroles. These 10-heterocorroles can be efficiently prepared fro bis(dipyrrin) metal complexes as precursors. Optical and electrochemical properties of these compounds are heavily dependent on the introduced heteroatoms at the meso-positions. The energy level of HOMOs and LUMOs of these molecules can be effectively manipulated by the proper choice of the heteroatoms.

Figure 1
New Porphyrinoids through Palladium-Catalyzed Couplings
Authors: Anguera Gonzalo , Kauffmann Brice , Borrell José I. , Borrós Salvador , Sánchez-García David 
Published: February 2020

Concise and versatile syntheses of oligopyrrolic derivatives are crucial for the preparation of macrocycles such as porphycenes, bronzaphyrins or cyclopyrroles. However, these precursors are usually obtained via long and tedious synthetic pathways. Besides, the key reactions of these procedures (i.e., Ullmann coupling, Stetter condensation) often hamper the preparation of functionalized macrocycles. As an alternative to these reactions, palladium-catalyzed couplings have emerged as promising synthetic methodologies.
Recently, our group has developed a new family of 2,2´-bipyrroles 1 that possesses a remarkable chemical stability, ascribed to the presence of electron withdrawing groups. This stability allows the preparation of α-brominated 2,2´-bipyrrole derivatives. With these halogenated 2,2´-bipyrroles in hand and using palladium-catalyzed cross-coupling reactions, such as the Suzuki coupling, a new family of chemically stable and easy-to-functionalize quaterpyrroles have been synthesized (2). A similar strategy has been applied to halogenated pyrroles to yield terpyrroles and related analogues (3). In this presentation, the preparation of such oligomers and their use to obtain new expanded porphyrins will be discussed.

Figure 1
Pyrazinacenes and Oxoporphyrinogens
Authors: Hill Jonathan P. , Miklik David , Svec Pavel , Matsushita Yoshitaka , Labuta Jan , Ishihara Shinsuke , D'Souza Francis , Ariga Katsuhiko 
Published: February 2020

Porphyrins substituted with antioxidant 2,6-di-tert-butylphenol substituents have been shown to exhibit different conformations based on the oxidation state of those substituents leading to the oxoporphyrinogens.1,2 On the other hand, pyrazinacenes are obtained by synthesis of linearly-fused 1,4-pyrazine groups giving molecules with potential as semiconductors, proton conductors or fluorescent labels. We have investigated both classes of compounds for their potential applications3,4 Here, we will describe the results of these investigations including highlighting the different compounds obtained from the porphyrin system, synthesis and structure in the phthalocyanine,5 TPA and HPB systems,6 and an extensive crystallographic analysis of the resorcinarene system.7 We will also present synthetic aspects of the pyrazinacene system including new synthesis pathways for higher derivatives.8 Finally, a molecular switch based on mechanical extension of an oxoporphyrinogen molecule will be described.9

References
(1) F. D’Souza, N. K. Subbaiyan, Y. Xie, J. P. Hill, K. Ariga, K. Ohkubo, S. Fukuzumi, J. Am. Chem. Soc. (2009) 131, 16138–16146. (2) J. P. Hill, I. J. Hewitt, C. E. Anson, A. K. Powell, A. L. McCarthy, P. Karr, M. Zandler, F. D’Souza, J. Org. Chem. (2004) 69, 5861–5869. (3) S. Ishihara, J. Labuta, T. Šikorský, J. V. Burda, N. Okamoto, H. Abe, K. Ariga, J. P. Hill, Chem. Commun. (2012) 48, 3933–3935 (4) A. Shundo, J. Labuta, J. P. Hill, S. Ishihara, K. Ariga, J. Am. Chem. Soc. (2009) 131, 9494–9495; J. Labuta, S. Ishihara, A. Shundo, S. Arai, S. Takeoka, K. Ariga, J. P. Hill, Chem. Eur. J. (2011) 17, 3558–3561. (5) J. P. Hill, N. K. Subbaiyan, F. D’Souza, Y. Xie, S. Sahu, N. M. Sanchez-Ballester, K. Ariga, Chem. Commun. (2012) 48, 3951–3953. (6) S. Jin, J. P. Hill, F. D'Souza, K. Ariga, (2016) in press. (7) D. Payne, J. P. Hill, F. D'Souza, K. Ariga, (2016) in press. (8) D. Miklik, P. Svec, J. P. Hill (2016) in press. (9) M. Perrin, J. P. Hill, D. Dulic, H. van der Zant, (2016) submitted.
Characterizing Reduction Reactions on Doped Titanium Oxides Using Intensity Modulated Photocurrent Spectroscopy
Authors: Policastro Steve A , Anderson Rachel , Hangarter Carlos 
Published: February 2020

The oxide on titanium is generally considered to behave as a semiconductor with a band-gap of approximately 3.1 eV. The interface between the oxide and the electrolyte can be envisioned in the semiconductor energy level diagram in Figure 1 and semiconductor properties of the oxides, such as the band gap, the flat band potential, and the dielectric constant, can be obtained from electrochemical impedance spectroscopy and Mott-Schottky tests. However, kinetic information, especially regarding reduction reactions occurring at the oxide surface is missing from these measurements. One approach for probing the catalytic properties of the oxide is to use IMPS to excite photoelectrons and measure the resulting oxide electrochemical response.
A kinetic model of the oxide behavior in response to photo-excitation was developed following the Ponomarev-Peter approach and was used to predict charge transport in the oxide band structure. From the band diagram in Figure 1, it can be supposed that incident photons, with energy greater than the band gap, will excite electrons from the valence band into the conduction band, leaving positively charged holes behind. Once in the conduction band, some of the electrons recombine with the holesand are lost while the majority will be transported through the external circuit to the counter electrode. Only a few will be able to travel to the interface to participate in a reduction reaction. The valence band holes, on the other hand, have much lower mobility than the electrons and, those that are not extinguished due to recombination, will reach the oxide-electrolyte interface and help drive water oxidation or other available reactions. Fitting the model parameters to the measured photo-electrochemical responses of the oxides provides a way to compare the effectiveness of the oxides to catalyze reduction reactions.
Figure 1. Band energy diagram for TiO2 shows the valence and conduction bands and the band gap in the oxide, the interface with the electrolyte, and approximate density of states at the interface for selected redox reactions. The shaded regions represent occupied density of states.
Acknowledgments
This work was sponsored by the Office of Naval Research, ONR, under grant/contract number N0001415WX00948; the views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Office of Naval Research, the U.S. Navy or the U.S. government.

Figure 1
Room-Temperature Atomic Layer Deposition of Al2O3 for Anticorrosion Coating on Metal Surfaces
Authors: Kanomata Kensaku , Ishikawa Makoto , Miura Masanori , Ahmmad Bashir , Kubota Shigeru , Hirahara Kazuhiro , Hirose Fumihiko 
Published: February 2020

A room-temperature atomic layer deposition (RT-ALD) of Al2O3 as an anticorrosion coating for metal surfaces was developed using trimethylaluminum (TMA) and a plasma excited humidified argon. The schematic of ALD system is shown in Fig.1. TMA as the aluminum precursor was introduced with a mass flow controller. A remote plasma system generating excited humidified argon was installed to the ALD chamber. The source gas for the oxidizing gas is a mixture of water vapor and argon. The plasma was generated in a glass tube with an induction coil with a frequency of 13.56 MHz and a RF power of 100 W. For the Al2O3 deposition, we repeated the cycle of TMA saturation and oxidizing gas treatment at RT. The TMA exposure was set at 5.86×10-3 Torr×40 sec. The saturation of TMA on the hydroxylated surface was confirmed by the IR absorption spectroscopy. The plasma excited oxidizing gas was injected for 2 min.
As a result, we show the anticorrosion test of ALD coated metal in a HCl solution. We used SUS430 plates with a size of 20×50×0.5 mm3 as the sample. In this test, we used a not-attenuated HCl solution with a concentration of 35 %. All the samples were immersed in the HCl solution for a certain amount of minutes at room temperature and we observed its surface coloring. Fig.2 shows a picture of the tested samples. The not-treated SUS430 sample clearly exhibits a white stain by the HCl corrosion. On the other hand, the Al2O3 coated sample maintained a mirror surface, which indicates that the RT-ALD coated film works as the anti-corrosion film against the acid solution. In the conference, we discuss the applicability of the RT-ALD to the anticorrosion coating for metal components.

Acknowledgements
This work was partly supported by JST-CREST, JSPS KAKENHI Grant Numbers 15H03536 and 15K13299.

Figure 1
On-Line Atmospheric Corrosion Monitoring of Field-Exposed Steels Using a Electrochemical Probe
Authors: Xia Da-Hai , Song Shi-Zhe , Jin Wei-Xian , Li Jian 
Published: February 2020

In this work, a new corrosion monitoring system for Q235B and T91 steels that exposed to Zhoushan offshore environment was established by using a portable EN monitoring system based on CompactRIO and atmospheric-corrosion-monitoring probes. Noise resistance was calculated and used as an indicator of corrosion resistance. A 20-day continuous monitoring result indicated that noise resistance correlated well with weight loss data. Wavelet analyses results of EN data indicated that Q235B undergone uniform corrosion and T91 suffered from localized corrosion, which was further confirmed by the surface observation.
Figure 1 EN measurement system for field test

Figure 1