bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Predicting the Optical Spectra of Fullerenes with Vibronic Coupling
Authors: Bourret Emmanuel , Stevenson Steven , Côté Michel
Published: August 2024

Following the mid-1980s discovery of fullerenes, their optical properties quickly drew a lot of attention as the intrinsically allowed electronic transitions did not seem to alone explain the complexities of their spectra. Even after more than three decades, there is still little knowledge of the intricate details of their absorption and emission spectra. The main issue with these carbon cages is the high density of electronic states in the energy range of interest. From an experimental standpoint, this means that high resolution spectra are needed to accurately distinguish the electronic and vibronic structure. On the other hand, such a high density of electronic states tests the limits of first-principle calculations, as the computational cost for precisely predicting electronic states quickly becomes prohibitive for systems as large as fullerenes.

In this presentation, we will discuss the challenges and importance of including vibronic coupling in the Ab initio calculation of fullerenes' optical spectra. This is necessary in order to gain a reliable interpretation of their electronic spectra and make the most of spectroscopy to probe the electronic structure of fullerenes.
Pseudocapacitive Storage in Molybdenum Oxynitride Nanostructures Reactively Sputtered on Stainless-Steel Mesh Towards an All-Solid-State Flexible Supercapacitor
Authors: Ranjan Bhanu , Rahman Habeebur
Published: August 2024

Exploiting pseudocapacitance in rationally engineered nanomaterials offers greater energy storage capacities at faster rates. The present research reports a high-performance Molybdenum Oxynitride (MoON) nanostructured material deposited directly over stainless-steel mesh (SSM) via reactive magnetron sputtering technique for flexible symmetric supercapacitor (FSSC) application. The MoON/SSM flexible electrode manifests remarkable Na+-ion pseudocapacitive kinetics, delivering exceptional ~881.83 F.g-1 capacitance, thanks to the synergistically coupled interfaces and junctions between nanostructures of Mo2N, MoO2, and MoO3 co-existing phases, resulting in enhanced specific surface area, increased electroactive sites, improved ionic and electronic conductivity. Employing 3D Bode plots, b-value, and Dunn’s analysis, a comprehensive insight into the charge-storage mechanism has been presented, revealing the superiority of surface-controlled capacitive and pseudocapacitive kinetics. Utilizing PVA-Na2SO4 gel electrolyte, the assembled all-solid-state FSSC (MoON/SSM||MoON/SSM) exhibits impressive cell capacitance of 30.7 mF.cm-2 (438.59 F.g-1) at 0.125 mA.cm-2. Moreover, the FSSC device outputs superior energy density of 4.26 μWh.cm-2 (60.92 Wh.kg-1) and high power density of 2.5 mW.cm-2 (35.71 kW.kg-1). The device manifests remarkable flexibility and excellent electrochemical cyclability of ~91.94% over 10,000 continuous charge-discharge cycles. These intriguing pseudocapacitive performances combined with lightweight, cost-effective, industry-feasible, and environmentally sustainable attributes make the present MoON-based FSSC a potential candidate for energy-storage applications in flexible electronics.

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(Invited) 2D Semiconductors from Spin-on Molecular Chemistries for Direct Large-Scale Integration
Authors: Balushi Zakaria Al
Published: August 2024

In this talk, I will discuss our recent developments centered on a process to produce fully soluble solutions from a unique molecular chemistry. This enables the creation of wafer-scale monolayers of MoS2, a prominent 2D semiconductor for logic and memory devices. This molecule can be dissolved in common solvents and spin-coated onto various substrates, including crystalline substrates, printed electrodes, and polymers. It can also be integrated into gate-all-around (GAA) 3D transistor structures for logic devices. Our method of rapidly synthesizing large-area MoS2 films, particularly in monolayer form via spin-coating, represents a novelty, as it hasn't been demonstrated previously with a single-source chemistry. This advancement is a significant step toward scalable synthesis of wafer-scale 2D semiconductor thin films, eliminating the need for post-growth wafer transfer techniques, a requirement with films grown by chemical vapor deposition (CVD) methods. Our fabrication process highlights the potential of using a single-source chemical precursor to develop monolayer 2D semiconductors that exhibit commendable transport characteristics and optical properties, which enhance with rising crystallization temperatures. Consequently, it holds promise as a semiconductor for microelectronic transistor channels in both back-end-of-line (BEOL) and front-end-of-line (FEOL) architectures.
(Invited) Two-Dimensional Organic-Perovskite Hybrid Materials and Heterostructures
Authors: Dou Letian
Published: August 2024

Epitaxial heterostructures based on oxide perovskites and III–V, II–VI and transition metal dichalcogenide semiconductors form the foundation of modern electronics and optoelectronics. Halide perovskites—an emerging family of tunable semiconductors with desirable properties—are attractive for applications such as solution-processed solar cells, light-emitting diodes, detectors and lasers. Their inherently soft crystal lattice allows greater tolerance to lattice mismatch, making them promising for heterostructure formation and semiconductor integration. Atomically sharp epitaxial interfaces are necessary to improve performance and for device miniaturization. However, epitaxial growth of atomically sharp heterostructures of halide perovskites has not yet been achieved, owing to their high intrinsic ion mobility and their poor chemical stability. Therefore, understanding the origins of this instability and identifying effective approaches to suppress ion diffusion are of great importance. In this talk I will present an effective strategy to substantially inhibit in-plane ion diffusion in two-dimensional halide perovskites by incorporating rigid π-conjugated organic ligands. Highly stable and tunable lateral and vertical epitaxial heterostructures, multiheterostructures and superlattices will be demonstrated. Furthermore, using these 2D heterostructures as a new platform, I will present our recent efforts in 1) quantitatively understanding the anion inter-diffusions and migrations, and 2) controlling and manipulating exciton transport and light-emission in halide perovskites.
Solid Solution Behavior of High Performance BiOBrxI1-X Photoanodes Probed Using Solid-State NMR, XRD and Optical Spectroscopy
Authors: Rana Md Masud , Kumar Navneet , Vrushabendrakumar Damini , Rajashekhar Harshitha , Bernard Guy , Alam Kazi , Meldrum Al , Michaelis Vladimir , Shankar Karthik
Published: August 2024

Bismuth oxyhalides (BIOX) are a family of solution-synthesizable 2D layered semiconductors constituted of earth-abundant elements namely bismuth, oxygen and the halogens. BIOX based thin films and heterojunctions are the subject of immense scientific interest due to their impressive performance in photocatalytic and photoelectrochemical devices. Solid solutions of Br/I bismuth oxyhalides exhibit continuously tunable absorption and emission spectra similar to that observed in mixed halide MAPbClxBryI3-x-y perovskites and mixed anion III-V GaAsxP1-x semiconductors. The excited state decay showed two components for all the mixed halide BiOX semiconductors with a dominant short-lived component in the nanosecond range and a weaker longer-lived component of ~100 ns. The average photoluminescence (PL) lifetime varied from 5.4 ns in bare BiOI to 1.49 ns in bare BiOBr with intermediate compositions exhibiting monotonically increasing average PL lifetimes with increasing iodine content. Using a combination of characterization techniques such as solid-state nuclear magnetic resonance (ssNMR), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and optical spectroscopy, we demonstrate the formation of atomic level solid solutions in Br/I bismuth oxyhalides. Through refinement of the lattice parameters using powder XRD and complementary atomic-level 209Bi SSNMR spectroscopy, we found that Vegard's law was obeyed by the BIOBrxI1-x solid solutions. By varying the Br:I ratio, it is also possible to tune the electronic band gap as well as the energy levels corresponding to the conduction band minimum (ECB, min) and the valence band maximum (EVB, max), thus allowing control over the thermodynamic driving force available to drive chemical reactions using photogenerated or electrically injected charge carriers. Suppression of the longitudinal optical phonon in solid solutions of Br/I bismuth oxyhalides is suggestive of lower phonon scattering of charge carriers and improved electronic transport. A synergistic enhancement of more than 1 order of magnitude in the photoelectrochemical water-splitting performance was obtained for the optimized solid solution (BiOBr0.67I0.33) under AM 1.5G 1 sun illumination. Our results pave the way for a one pot synthesis protocol to form BiOX thin films, powders and colloidal suspensions with deterministic control over the stoichiometry.
(Invited) Photoelectrochemistry of Monolayer 2D Semiconductors: Quantifying Band Gap Renormalization Effects and Hot Carrier Extraction
Authors: Sambur Justin , Austin Rachelle , Almaraz Rafael , Krummel Amber , Montoya-Castillo Andres , Sayer Tom , Toole Justin
Published: August 2024

The fundamental problem that limits the solar energy conversion efficiency of conventional semiconductors such as Si is that all absorbed photon energy above the band gap is lost as heat. The critical question that our research addresses is: Can we avoid energy losses in semiconductors?Hot-carrier systems that avoid such losses have tremendous potential in photovoltaics and solar fuels production, with theoretical efficiencies of 66% (well above the detailed-balance limit of 33%). Ultrathin 2D semiconductors such as monolayer (ML) MoS2 and WSe2 have unique physical and photophysical properties that could make hot-carrier energy conversion possible. The specific knowledge gap in the field is how the energy levels of 2D semiconductors move with applied potential and/or illumination, making the driving force for charge transfer (ΔG
0´) unclear. Since ΔG
0´ governs the hot-carrier extraction rate (k
ET), understanding how and why ΔG
0´ changes under solar fuel generation conditions is critical to controlling k
ET relative to the cooling rate. Absence of this critical information is limiting our ability to perform hot-carrier photochemistry. Our research team has employed photocurrent spectroscopy, steady-state absorption spectroscopy, and in situ femtosecond transient absorption spectroscopy as a function of applied potential to characterize underlying steps in a ML MoS2 photoelectrochemical cell. The rich data set informs us on the timescales for hot-carrier generation/cooling and exciton formation/recombination, as well as the magnitudes of changes in exciton energy levels, exciton binding energies, and the electronic band gap. These findings open the possibility of tuning the hot-carrier extraction rate relative to the cooling rate to ultimately utilize hot-carriers for solar energy conversion applications.
Interface Engineering for Light Activated Doping in Large Area Transition Metal Dichalcogenides
Authors: Ghoshal Debjit , Miller-Link Elisa , van de Lagemaat Jao
Published: August 2024

2D materials have shown great potential in microelectronics and optoelectronics. However, a major challenge in commercializing these materials is the inability to effectively dope them at a wafer scale. Due to the atomic thinness of 2D materials these are very sensitive to ion beams making doping by ion implantation extremely challenging. While electrostatic gating can be used to effectively dope these materials and are ideal for studying fundamental physics, the device architecture is extremely complex and unsuitable for commercial applications. Avenues to dope these materials via molecular doping have also been explored but have provided limited success due the instability of these molecular dopants. We propose the use of interface chemistry and concomitant exposure to visible light (with energy above the bandgap of the TMDCs) for photodoping these materials. We shed light on the fundamental mechanism of the doping process. Additionally, we show the ability to achieve spatial control over the doping process by selectively exposing certain parts of the TMDCs to light of the appropriate wavelength. We further demonstrate the extension of this idea to pattern areas with different doping densities by selective exposure of certain parts of the sample to the laser. We anticipate that the scalability and ease of implementation of this approach will address one of the major issues preventing the “Lab to Fab” transition of 2D materials and facilitate its seamless integration for commercial applications.
Effect of Functionalized Carbon Nanotubes and Graphene Oxide Nanoribbons on the Supercapacitive Behavior of Zr-Based Metal-Organic Frameworks in Acid Media
Authors: Heiba Asmaa R. , Abdelsalam Mohamed O , Yoon Taeho , El Sawy Ehab N
Published: August 2024

Metal-organic frameworks (MOFs) as a kind of crystalline porous materials have attracted much attention due to their high surface area and high electrochemical performance as electrode materials in supercapacitors 1. Recently, there has been a lot of interest in functionalized multiwalled carbon nanotubes (F-MWCNTs) based materials and especially graphene oxide nanoribbons (GONRs), which have unusual characteristics of ultrathin two-dimensional structures and, as promising materials for supercapacitors and other electrochemical energy storage devices. The F-MWCNTs and GONRs' high electrical conductivity, highly changeable surface area, strong chemical stability, excellent mechanical behavior, and capacity to modify attributes for the desired application are behind the reasons for choosing to make a composite of these materials with Zr-MOF 2.

In this work, Zr-MOF was synthesized using the solvothermal method 3, MWCNTs were functionalized using acid washing (3 M H2SO4: 1 M HNO3), and GONRs were fabricated using the oxidative unzipping method 4. The Zr-MOF/F-MWCNTs and Zr-MOF/GONRs composites were prepared through physical mixing. The physical and chemical structures of the synthesized Zr-MOF, F-MWCNTs, and GONRs were evaluated using XRD, SEM, TEM, FT-IR, Raman spectroscopy, and XPS. The supercapactive behavior of the prepared composites was evaluated in comparison to their components (Zr-MOF, F-MWCNTs, and GONRs) in 1M H2SO4 utilizing various evaluation systems (three and two-electrode systems). Zr-MOFs showed a high specific capacitance (248 F/g at 1 A/g), making it a promising supercapacitor electrode material. That performance is dramatically improved by the addition of the nanocarbon materials (F-MWCNTs and GONRs). Zr-MOF-GONRs showed the highest specific capacitance (448 F/g at 1 A/g), with a large potential window (1.7 V) in the three-electrode system extended to (2V) in the two-electrode system, and good stability over 10,000 cycles at a high current density of 10 A/g.

Reference:

(1) Tan, Y.; Zhang, W.; Gao, Y.; Wu, J.; Tang, B. Facile Synthesis and Supercapacitive Properties of Zr-Metal Organic Frameworks (UiO-66). RSC Adv.
2015, 5 (23), 17601–17605. https://doi.org/10.1039/c4ra11896k.

(2) Shrivastav, V.; Sundriyal, S.; Tiwari, U. K.; Kim, K. H.; Deep, A. Metal-Organic Framework Derived Zirconium Oxide/Carbon Composite as an Improved Supercapacitor Electrode. Energy
2021, 235, 121351. https://doi.org/10.1016/j.energy.2021.121351.

(3) Abdelhamid, H. N. UiO-66 as a Catalyst for Hydrogen Production: Via the Hydrolysis of Sodium Borohydride. Dalton Trans.
2020, 49 (31), 10851–10857. https://doi.org/10.1039/d0dt01688h.

(4) Kosynkin, D. V.; Higginbotham, A. L.; Sinitskii, A.; Lomeda, J. R.; Dimiev, A.; Price, B. K.; Tour, J. M. Longitudinal Unzipping of Carbon Nanotubes to Form Graphene Nanoribbons. Nature
2009, 458 (7240), 872–876. https://doi.org/10.1038/nature07872.
Completely Monodisperse Graphene Dispersions Imparting Film of High Specific Capacitance
Authors: Atrey Isha , Shukla Anupam
Published: August 2024

Graphene has emerged as a remarkable material with diverse applications in the field of optoelectronics and energy storage. However, the challenge lies in producing high-quality graphene via liquid phase methods that can match the optoelectronic properties achieved through expensive techniques like chemical vapor deposition (CVD) or micromechanical cleaving. Existing liquid phase methods suffer from issues such as graphene oxidation during production, layer number dispersion, and small flake size, which significantly compromise the overall quality of the material and its potential applications.

We demonstrate the synthesis of completely layer number-monodisperse graphene dispersions using anodic electrochemical exfoliation with exceptional optoelectronic properties comparable to CVD-derived graphene. A notable highlight of our research is the high specific capacitance of the film formed from the electrochemically exfoliated graphene dispersions (259- 666 F g-1), which is highly promising for capacitive energy storage applications. We have successfully addressed the difficulties related to oxidation and the uneven distribution of layers, achieving large flake sizes. This progress was achieved by employing a tailored synthesis method maneuvered through electrochemical characterizations and precise management of experimental variables during the intercalation, exfoliation, and further processing steps. Thus, this research contributes significantly to the ongoing advancements in graphene synthesis and graphite intercalation science.
Chemical Patterning of Graphene, Graphite and MoS2: From Microscale to Nanoscale
Authors: Mali Kunal S. , De Feyter Steven
Published: August 2024

Chemical patterning of 2D materials is relevant in several different domains of science and technology with exciting possibilities in electronics, catalysis, sensing, and photonics. Despite intense efforts, spatially controlled, (multifunctional) covalent chemical patterning of graphene and related 2D materials is not straightforward. In my talk, I will present examples of covalent chemical patterning of graphene, graphite and MoS2 using diazonium chemistry. In the first case, spatially resolved multicomponent covalent chemical patterning of single layer graphene was achieved using a facile and efficient method. Three different functional groups could be covalently attached to the basal plane in dense, well-defined micrometer wide patterns using a combination of lithography and a self-limiting variant of diazonium chemistry requiring no need for graphene activation. The layer thickness of the covalent films could be controlled down to 1 nm. In the second case, i will present sub-10 nm chemical patterning of graphite achieved using the electrochemical diazonium chemistry. Here, an elegant combination of covalent and non-covalent chemistry was used to achieve 5-6 nm wide linear chemical patterns with excellent pattern transfer fidelity. In the last example, I will briefly share our initial results on the nanoscale chemical patterning of MoS2 using electrochemical diazonium chemistry. Throughout the discussion, i will highlight the critical role of scanning probe microscopy, namely STM, AFM and AFM-IR in providing critical spatial and spatio-chemical information at the nano and micrometer scale where conventional analytical techniques fail to provide accurate information.
Phase Engineering of Two-Dimensional WS2 Nanostructures for Superior Hybrid Supercapacitors
Authors: Shinde Pragati A. , Ariga Katsuhiko
Published: August 2024

Two-dimensional (2D) tungsten sulfide (WS2) has recently emerged as a nontrivial material for electrochemical applications; however, the boundaries associated with its 1T (instability) and 2H (low electrical conductivity) phases limit its electrochemical parameters. In this work, this issue is addressed using an exclusive chemical approach to evolve a dual-phase 1T-2H WS2 heterostructure that combines two different 1T (trigonal) and 2H (hexagonal) phases directly on the current collector which demonstrated 2D transformable phase structure, large interlayer distance, and highly exposed edge active sites. A simple inert-atmosphere annealing approach under phosphorus vapors is designed to elicit a fractional phase conversion of WS2 from conventional 2H to the 1T phase, where phosphorus is accommodated in the WS2 interspace and lattice, resulting in interlayer expansion. Theoretical calculations confirmed that the 1T WS2 structure formed after phosphorus doping exhibits semimetallic feature with no band gap, thereby elucidating the high electrical conductivity. The presence of edge-enriched metallic phase and interlayer engineering of 1T-2H WS2 heterostructure validates the exceptional sodium (Na+) ion intercalation when tested in hybrid supercapacitor (HSCs) against Prussian blue analog (PBA) cathodes. As a result, the assembled HSC cell with a 1T-2H WS2 heterostructured anode and a CuFe-PBA cathode shows superior specific energy of 65.5 Wh kg-1 at a specific power of 784 W kg-1, and maintains 75% rate capability and 95.7%

cycling stability over 10,000 cycles. This work paves a technique for engineering a simple phase transition of 2D materials and sheds light on the expansion of high-performance next-generation energy storage systems.
(Invited) Development of Leuco Ethyl Violet as Self-Activating Prodrug Photooxygenation Catalyst of Amyloid-β
Authors: Mitsunuma Harunobu , Furuta Masahiro , Matsukawa Ryota , Shizu Katsuyuki , Kaji Hironori , Kawashima Shigehiro A , Hori Yukiko , Tomita Taisuke , Sohma Youhei , Kanai Motomu
Published: August 2024

Abnormal aggregation of amyloid-β (Aβ) and tau protein (tau), called amyloid, is characteristic of Alzheimer's disease (AD). Reducing amyloid levels in AD patients is expected to be an effective approach to AD treatment. To inhibit the hydrophobic interaction of amyloid, which is the cause of toxic aggregates, we planed to generate singlet oxygen by activating oxygen in vivo through photocatalysis, thereby introducing oxygen atoms to amyloid protein and inhibiting aggregation. In accordance with this concept, we are developing photooxygenation catalysts with a switch function that generates singlet oxygen only in the presence of amyloids. We have succeeded in reducing amyloid in AD model mouse brain non-invasively with this photo-oxygenation catalyst. However, moderate catalytic activity and the side effect of scalp damage have been problematic. This time, we identified leucoethyl violet (LEV) as a highly active, amyloid-selective, blood-brain barrier (BBB)-permeable photooxygenation catalyst. LEV is a self-activating procatalyst by external redox stimuli. Autoxidation of LEV by a hydrogen atom transfer process under light irradiation produced active catalyst species Ethyl Violet (EV) only in the presence of amyloids. LEV showed higher catalytic activity than the previously developed photooxygenation catalyst and realized oxygenation of human Aβ and tau. Taking advantage of LEV's high activity and amyloid selectivity, improved BBB permeability, and low cytotoxicity, photooxygenation of Aβ was achieved in an AD model without scalp injury.

Figure 1
Lattice Symmetry-Guided Charge Transport and Recombination in Supramolecular Assemblies
Authors: Emmanuele Ruggero , Ma Xuedan
Published: August 2024

Synthetic soft materials mimicking biological structures are promising for many applications in fields such as photovoltaics and photocatalysis. For these applications, a deep understanding of the charge- and energy-transfer mechanisms is required to build more efficient devices. In this work, we investigate self-assembled 2D supramolecular structures using angle-resolved photoluminescence (PL) imaging techniques and decompose the optical transition dipoles in the supramolecular structures. Combining these optical studies with Monte Carlo simulations, we reveal the important role played by lattice symmetry in charge dissociation, transport, and recombination, as well as the exciton spin states. These mechanistic findings have important implications for engineering soft materials towards efficient energy conversion and photocatalytic applications.
(Invited) Molecular Donor-Acceptor Systems Derived from Aromatic Heterocycle-Fused Porphyrins
Authors: Wang Hong , Moss Austen , Arvidson Jacob , Jang Youngwoo , Alsaleh Ajyal , D'Souza Francis
Published: August 2024

Photoinduced charge separation (CS) in molecular donor-acceptor (D-A) systems is crucial for achieving efficient solar energy conversion in various applications. Despite significant efforts to develop molecular D-A systems over the past decades, it remains a challenge to bring the lifetime of the charge separation state to ms range, which is much shorter than the CS lifetime (~1 s) in natural photosynthetic systems. In this talk, a donor-acceptor system with long-lived charge-separation state (37.2 μs) will be presented. This donor-acceptor system was derived from π-extended porphyrins fused with aromatic heterocycles. Porphyrins fused with aromatic heterocycles represent one fascinating yet very challenging frontiers in chemistry and materials science.1-4 The Wang group has been engaged in developing concise and versatile synthetic and functionalization methods for π-extended porphyrins. The availability of these methods offers easy access to many π-extended porphyrins with novel functionalities.5-7 In this talk, the synthesis, characterization, and the optical and photophysical properties of π-extended porphyrins fused with 5-, 6, and 7-membered rings including 12H-benzo[f]benzo[4,5]imidazo[2,1-a]isoindole and 1,10-phenanthroline, porphyrins will also be presented.

Reference

Stepien, E. Gonka, M. Zyla and N. Sprutta, Chem. Rev., 2017, 117, 3479-3716.

Narita, X. Y. Wang, X. Feng and K. Mullen, Chem. Soc. Rev., 2015, 44, 6616-6643.

P. Lewtak and D. T. Gryko, Chem. Commun., 2012, 48, 10069-10086.

K. S. Davis, A. L. Thompson and H. L. Anderson, J. Am. Chem. Soc., 2011, 133, 30-3.

Hu, M. B. Thomas, W. A. Webre, A. Moss, R. G. W. Jinadasa, V. N. Nesterov, F. D’Souza and H. Wang, Angew. Chem. Int. Ed., 2020, 45 (132), 20250-20257.

Moss, Y. Jang, J. Arvidson, V. N. Nesterov, F. D’Souza and H. Wang, Chem. Sci., 2022, 13, 9880 -9890.

Moss, D. E. Nevonen, Y. Hu, V. N. Nesterov, V. Nemykin and H. Wang*, ACS Phys. Chem. Au, 2022, 2, 6, 468-481.
(Invited) Synthesis and Photophysical Properties of Linear Coordination Type Complexes Having Electron Donor/Acceptor Moieties
Authors: Sakuda Eri
Published: August 2024

The energy and electron transfer processes in the organic / inorganic D–A connection system can be freely manipulated by vibronic interaction.Until now, we synthesized the complexes having acceptor moiety was introduced as a substituent to induce electrostatic/coulomb interaction, but from now on, donor and acceptor moieties should be introduced intramolecular or intermolecular in order to induced a donor-acceptor interaction and express dynamic exciton. Then, we synthesized a platinum complex with phenothiazine as a donor and an organoboron compound as an acceptor. Unfortunately, the charge separation state could not be confirmed, but it is thought that it will be possible by changing the central platinum complex site. Therefore, we investigated the synthesis of a linear complex with a new donor-acceptor site.

Figure 1
(Invited) Exciton Dynamics in Triplet Fusion of Diphenylanthracene in Fluid Solution and Crystalline Solid
Authors: Tsuchiya Shuta , Miura Tomoaki , Seki Kazuhiko , Ikoma Tadaaki
Published: August 2024

Triplet fusion (TF) has recently attracted attention because of its great potential of various applications. Since high reaction efficiency of TF is demanded in any applications, it is necessary to clarify the mechanism of triplet exciton dynamics that is an important elementary process to enhance the TF efficiency. Therefore, in this paper, we study the triplet exciton dynamics of 9,10-diphenylanthracene (DPA), which shows the TF-based fluorescence, in a solvent of tetraethylene glycol dimethyl ether and in polycrystal of DPA, in combination with the triplet sensitization using platinum octaethylporphyrin. The observed emission kinetics and their magnetoluminescence effect indicate that the rotational and the multitrapping diffusions of the triplet exciton play an inherent role respectively in the fluid solution and in the polycrystalline solid.
(Invited) Exciton Dynamics for Spin Qubits
Authors: Kobori Yasuhiro , Fuki Masaaki , Hasobe Taku
Published: August 2024

Singlet fission (SF) can generate exchange-coupled triplet pairs. This may lead to realizations of quantum manipulation and quantum sensing using entangled multiple qubits. However, direct manipulation of the quantum coherence has been limited in the triplet pairs. Here we show that the quantum coherence of SF-derived, weakly coupled spin correlated triplet pair (T+T) in biphenyl linked tetracece oligomer systems by using time-resolved pulsed electron paramagnetic resonance method.
(Invited) Exploitation of Advanced Materials and Process for Sustainable Perovskite Solar Cells
Authors: Jung Hyun Suk
Published: August 2024

All solid-state solar cells based on organometal trihalide perovskite absorbers have already achieved distinguished power conversion efficiency (PCE) to 26.1% and further improvements are expected up to 27%. Now, the research on perovskite solar cells (PSCs) has been moving toward commercialization. To facilitate commercialization of these great solar cells, some technical issues such as long-term stability, large scale fabrication process, Pb-related hazardous materials, and environmentally-burdened toxic solvent-based process need to be solved.

This talk is dealing with our recent efforts to facilitate commercialization of perovskite solar cells. For examples, we introduce a recycling technology of perovskite solar cells, which covers the regeneration process of Pb contained perovskite layer as well as recycling process of Au electrodes and transparent conducting oxide glass [1, 2]. Also, novel strategies for recycling toxic solvents such as DFM, used in fabricating PSCs are introduced, which is critical to realize close loop recycling process of PSCs. Finally, recent studies for achieving high efficiency PSC using ecofriendly solvent are demonstrated.
Machine-Learning Accelerated Description of Polarons in 2D Lead Halide Perovskites
Authors: Graupner David , Kilin Dmitri S.
Published: August 2024

MLFF-based MD trajectories to compute NAC and excited-state dynamics. At each stage, results based on machine learning are compared to traditional ab initio based electronic dissipative dynamics.

The limits of this method are explored as we increase the timescale of the calculation beyond those allowed by ab initio molecular dynamics and to determine the effectiveness of MLFF-MD when used for excited-state nonadiabatic dynamics simulations using atomistic models that include charge injection or when an excited-stated potential energy surface is used to account for changes due to an excitation.
(Invited) Plasmon Induced Hot Electron Transfer from Doped Semiconductor Nanocrystals
Authors: Lian Tianquan
Published: August 2024

In recent years, a new class of plasmonic materials based on doped semiconductor NCs has been developed. Similar to noble metals, localized surface plasmon resonances in doped semiconductor NCs arises from the coherent collective oscillation of free carriers within the NCs. The wide tunability of free carrier concentration results in tunable plasmon bands spanning from the visible to mid-infrared regime and these plasmonic semiconductor NCs have been reported to drive plasmonic hot carrier photocatalysis under near IR light illumination. These reports suggest that plasmonic semiconductors is an interesting material platform for efficient near IR driven hot carrier photocatalysis. So far the reported efficiencies are low and the mechanisms of hot carrier generation, transfer and recombination are unclear. There are interesting similarities and differences between metal and semiconductor plasmonics. First, plasmons in semiconductors can decay by inter- (band gap) and intra- band plasmon decay. Furthermore, charge transfer transition in semiconductor heterostructures have been extensively reported; can plasmon decay in plasmonic-semiconductor/semiconductor junctions proceed by exciting interfacial ET across the junction, similar to the PICTT pathway reported for metal/semiconductor junctions? Second, in plasmonic semiconductor materials, where there is a lack of states within the p-semiconductor bandgap, the transferred electrons in the accepting semiconductor CB can recombine only with the VB holes in the plasmonic semiconductor. This process requires dissipation of ~ >1 eV energy, which may slow down the recombination rate. In this talk, I will discuss our recent progresses in studying plasmon induced hot electron transfer and recombination in plasmonic semiconductor/semiconductor interfaces.
(Invited) Lithium Phosphorus Sulfide Chloride−Polymer Composite Via the Solution−Precipitation Process for Improving Stability Toward Dendrite Formation of Li-Ion Solid Electrolyte
Authors: Liu Gao
Published: August 2024

Improving the mechanical strength of ceramic solid electrolytes such as lithium phosphorus sulfide families for pressure-driven dendrite blocking as well as reducing the electronic conductivity to prevent a dendrite formation inside the electrolytes are very important to extend the lifespan of all-solid-state lithium-metal batteries. Here, we propose a low-temperature solution−precipitation process to prepare polymer−solid electrolyte composites for a highly uniform polymer distribution in the electrolyte to enhance their mechanical strength and reduce their electronic conduction. The composites with up to 12 wt % of polymer are prepared, and the composites exhibit high ionic conductivities of up to 0.3 mS/cm. Furthermore, the electrochemical stability of the electrolyte composites on Li striping/plating cycles is investigated. We confirm that the proposed solution− precipitation process makes the composite much more stable than the bare solid electrolyte and causes them to outperform similar composites from the other existing preparation methods, such as mechanical mixing and solution dispersion.

Figure 1
(Invited) Integrating Material Design, in-Operando Spectroscopy and Device Testing for Next Generation Lithium-Sulfur Batteries
Authors: Kalra Vibha
Published: August 2024

Rechargeable batteries with conversion type electrodes are attractive due to their ability to achieve higher capacity through multi-electron transfer reactions. Elemental sulfur is one of the most interesting materials amongst all conversion-based cathodes because of its high theoretical capacity (~1675 mAh/g – 5-10-fold higher than Li-ion batteries), natural abundance, non-toxicity, and cost-effectiveness. In this talk, I will share our group’s research on integrating material design and fabrication, in-operando and postmortem spectroscopy, and device assembly and testing (coin/pouch) to study and develop next generation lithium-sulfur batteries. I will discuss representative projects on studying cathode, anode, and electrolyte chemistries to mitigate key challenges, such as the notorious polysulfide shuttle and lithium instability, among others.
Cobalt Complex of an N-Linked Carbacorrole Analog: Axial Ligand Effect on Electronic Structure
Authors: Ishida Masatoshi
Published: August 2024

Corrole, recognized as a contracted tetrapyrrolic macrocycle featuring an α,α'-linked bipyrrole moiety, has garnered attention for its unique trianionic N4 donor environment at the inner core. This characteristic has prompted the exploration of various high-valent metal species for potential catalytic applications. In our pursuit of uncovering new reactivity in metallo-corroles, we have previously synthesized a distinct carbacorrole ligand known as N-confused/N-linked corrole analogs.[1] The former variant incorporates an inverted pyrrole moiety connected at the α and β’-linking positions, while the latter exhibits a unique linkage between the α-pyrrole ring and the pyrrolic N site. The resulting [NNNC] coordination environment of carbacorroles stabilizes distinctive organometallic species, particularly with copper(III) ions.[2]

In this study, we synthesized novel cobalt complexes featuring an N-linked carbacorrole analog with a benzo annulation, referred to as benzonorrole. The electronic structure of the ensuing complex is notably influenced by the axial ligands. The monodentate pyridine axial coordination to the cobalt norrole complex revealed unique reactivity, resulting in an oxygenated product at the inner carbon site. The oxygenated cobalt norrole complex can be characterized as a singlet Co(II) ligand radical at the ground state, as evidenced by various spectroscopic methods and magnetic susceptibility measurements. Upon substitution with a triphenylphosphine ligand, the resulting five-coordinated cobalt norrole complex was found to be stable and considered a diamagnetic cobalt(III) species, devoid of redox noninnocent character. This talk will delve into the detailed structure and electrochemical properties of these intriguing complexes.

[1] Fujino, K.; Hirata, Y.; Kawabe, Y.; Morimoto, T.; Srinivasan, A.; Toganoh, M.; Miseki, Y.; Kudo, A.; Furuta, H. Angew. Chem. Int. Ed.
2011, 50, 6855-6859; Toganoh, M.; Kawabe, Y.; Uno, H.; Furuta, H. Angew. Chem. Int. Ed.
2012, 51, 8753-8756.

[2] Maurya, Y.; Noda, K.; Yamasumi, K.; Mori, S.; Uchiyama, T.; Kamitani, K.; Hirai, T.; Ninomiya, K.; Nishibori, M.; Hori, Y.; Shiota, Y.; Yoshizawa, K.; Ishida, M.; Furuta, H. J. Am. Chem. Soc. 2018, 140, 6883-6892.
Pot-Economical Approaches to the Synthesis and Functionalization of Phthalocyanines for Clean Energy Production
Authors: Zanotti Gloria , Palmeri Federica , Raglione Venanzio
Published: August 2024

The last decades have witnessed a growing interest in reducing the ecological and economic impact of chemical processes, with an important focus on the development of more environmentally friendly procedures and methodologies in organic synthesis. Given the extreme versatility and technological importance of phthalocyanines for a variety of applications, of which clean energy production is among the most relevant, the design and study of alternative and less-impacting synthetic approaches to the conventional ones have gained importance in the last years. Their synthesis in solution frequently requires reaction media such as high boiling point alcohols (pentanol, hexanol), dimethylaminoethanol, chlorobenzene, quinoline, and α-chloronaphthalene, most of which are toxic and non-environmentally friendly. Some green synthetic approaches based on solvothermal methods [1,2], mechanochemistry [3], or alternative sources of energy such as microwaves [4-6] and ultraviolet radiation [7], have been developed in order to minimize if not overcome this issue and provide less-impacting experimental conditions for their production. A less studied but very promising approach concerns the development of pot-economical processes, in which two or more reactions take place in the same reaction vessel. The advantage of this approach is twofold: on the one hand it significantly reduces the amount of chemicals required to synthesize and purify a target product, on the other it minimizes the total time required to obtain it. Clearly, the process must be carefully designed in order to avoid yield decreases due to side reactions.

In this contribution, the rational design of symmetrical and unsymmetrical substituted phthalocyanines by means of pot-economical approaches in solution will be shown and discussed, along with an estimation of the environmental and economic impact with respect to the related conventional procedures. Examples will be shown both of derivatization of already formed macrocycles, following a “late-stage functionalization” approach [8], and of derivatization of phthalonitriles followed by in-situ metal-templated cyclotetramerization. Furthermore, their optical and electrochemical characterization will be shown, discussed and compared with each other by relating the obtained data to their different chemical structures. Finally, examples of their implementation in the field of organic optoelectronics, with a focus on perovskite solar cells, will be presented.

D. Li et al CrystEngComm 2018, 20, 2749–2758.

D. Li, et al RSC Adv. 2021, 11, 31226–31234.

D. Langerreiter et al Angew. Chem. Int. Ed. 2022, 61, e202209033.

A. Shaabani et al Dyes Pigm. 2007, 74, 279–282.

D. Villemin et al Molecules 2001, 6, 831–844.

A.C.S. Gonzalez et al. J. Porphyr. Phthalocyanines 2020, 24, 947–958.

Y. Saito et al Chem-NanoMat 2015, 1, 92–95.

G. Zanotti et al ChemPlusChem 2020, 85, 1–12
Transforming Waste into Valuable Chemicals: CO2 Conversion Enabled by Porphyrin-Based Catalysts
Authors: Gallo Emma
Published: August 2024

Carbon dioxide is the primary greenhouse gas responsible for global warming and the resulting climate change, which is provoking a significant increase in extreme weather events that impact our health, environment, and economy. Nowadays the scientific community is focusing many efforts on the use of CO2 as a C1 source in the synthesis of a wide range of useful products, in alignment with circular economy principles [1].

Here we report the reaction of CO2 with epoxides and aziridines, forming cyclic carbonates and oxazolidin-2-ones, by a 100% atom-efficient procedure promoted by porphyrin-based catalytic systems [2]. Considering that the contemporary presence of electrophile and nucleophile promoters is usually required for these classes of transformations, several binary and bifunctional porphyrin-based systems will be discussed with the final goal to underline the advantages of employing these systems in terms of broad applicability and eco-tolerance. Porphyrins exhibit remarkable chemical versatility, allowing for precise tuning of catalytic performances and reaction chemo-selectivity. Furthermore, the heterogenization of single-site catalysts onto solid supports enhances practical applicability [3].

In addition, synthetic protocols will also be discussed from a mechanistic point of view on the basis of spectroscopic and theoretical studies and taking into account the identification of active intermediates [4].

References

[1] A. Alok, R. Shrestha, S. Ban, S. Devkota, B. Uprety, R. Joshi J. Environ. Chem. Eng., 2022, 10, 106922.

[2] a) M. Cavalleri, C. Damiano, G. Manca, E. Gallo Chem. Eur. J., 2023, 29, e202202729. b) C. Damiano, P. Sonzini, G. Manca, E. Gallo Eur. J. Org. Chem., 2021, 2807. c) P. Sonzini, C. Damiano, D. Intrieri, G. Manca and E. Gallo Adv. Synth. Catal.
2020, 362, 2961.

[3] P. Sonzini, N. Berthet, C. Damiano, V. Dufaud, E. Gallo J. Catal., 2022, 414, 143. b) C. Damiano, A. Fata, M. Cavalleri, G. Manca, E. Gallo submitted.

[4] C. Damiano, N. Panza, J. Nagy, E. Gallo, G. Manca New J. Chem., 2023, 47, 4306.

Figure 1
Understanding the Role of Second Coordination Sphere Effects on Electrochemical CO2 Reduction with Iron Porphyrins
Authors: Nichols Eva Megan
Published: August 2024

Enzymes achieve fast kinetics and high selectivity by carefully controlling the functional groups in the vicinity of the active site. Collectively, these peripheral groups are termed the Second Coordination Sphere (SCS). Synthetic chemists have long been inspired by the biological importance of the SCS and have demonstrated that the SCS can play an important role in a number of transformations promoted by molecular catalysts. In particular, it is well-known that the kinetics of electrochemical CO2 reduction depend on the presence of SCS functional groups capable of proton transfer, hydrogen bonding, or electrostatic interactions. However, many aspects still remain incompletely understood, such as the pKa
requirements for protic SCS groups, the positional dependence of the SCS group with respect to the active site, and the role(s) of the SCS group in the catalytic reaction mechanism. This talk will showcase various SCS modifications made to iron porphyrins and, relying on a combination of molecular synthesis, electrochemistry, spectroscopy, and computational insights, will outline the various ways that the SCS can perturb reaction mechanisms and outcomes of electrochemical CO2 reduction.
Molecular Level Insights into the Chemical Reactivity of Metal Porphyrins and Iodine at the Solution/Solid Interface
Authors: Mazur Ursula , Hipps K. W.
Published: August 2024

Highly oxidized metalloporphyrins (MP) exhibit unusual electronic properties and unique reactivities and are known to serve as intermediates in a number of biological reactions. Of special interest are MP systems that can electronically communicate during the oxidative processes. Model synthetic porphyrins substituted with first row transition metals can react with dihalides and undergo metal oxidation or form MP p-cation radicals. MP dimers that are covalently connected by short alkane or alkene bridges exhibit electronic coupling between the macrocycles which can strongly influence the outcome of the oxidation reaction by dihalides. Metal surfaces also can serve as a conduit for electron transfer and promote cooperative behavior during reactions between adsorbed MP and axial ligands. In this contribution, we present STM experimental results and supporting theoretical calculations of the reactions dynamics of I2 and metal (Co, Zn, and Ni) porphyrins adsorbed on metallic supports. Single molecule level STM imaging was accomplished in-situ under ambient solution conditions. We uncovered unusual surface chemistry and surface modulated cooperativity in the redox reactions. Computations corroborate our experimental findings. The high-resolution images obtained for these reactions at the single molecule level combined with theoretical studies offer insights into surface redox chemistry, surface cooperativity, and surface-driven catalysis.
Symmetry Breaking Charge Separation in Far-Red Absorbing Bisstyryl-Bodipy Dimers
Authors: D'Souza Francis , Yahagh Aida , Kaswan Ram , Kazemi Shahrzad , Karr Paul
Published: August 2024

Symmetry breaking charge transfer is one of the important photo-events occurring in photosynthetic reaction centers that is responsible for initiating electron transfer leading to a long-lived charge-separated state and has been successfully employed in light-to-electricity converting optoelectronic devices. Here, we report the synthesis of far-red absorbing and emitting BODIPY-dimer to undergo symmetry-breaking charge transfer leading to charge-separated states of appreciable lifetimes in polar solvents. Compared to its monomer analog, both steady-state and time-resolved fluorescence originating from the S1 state of the dimer revealed quenching which increased with an increase in solvent polarity. The electrostatic potential map from DFT and the time-dependent DFT calculations suggested the existence of a quadrupolar type charge transfer state in polar solvents, and the singlet excited state to be involved in the charge separation process. The electrochemically determined redox gap to be smaller than the energy of the S1 state supporting thermodynamic feasibility of the envisioned symmetry-breaking charge transfer and separation. The spectrum of the charge-separated state arrived from spectroelectrochemical studies, revealing diagnostic peaks helpful for transient spectral interpretation. Finally, ultrafast transient pump-probe spectroscopy provided conclusive evidence of diabatic charge separation in polar solvents by far-red pulsed laser light irradiation. The measured lifetime of the final charge-separated states was found to be 165 ps in dichlorobenzene, 140 ps in benzonitrile, and 43 ps in dimethyl sulfoxide, revealing their significance in light energy harvesting, especially from the less-explored far-red region.