bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of Highly-Ordered Tetrabenzorporphyrin Films Controlled by Supramolecular Assemblies and Precursor Approach
Authors: Ueno So , Yamauchi Mitsuaki , Yamada Hiroko
Published: August 2024

The control of the orientation and packing structures of small organic semiconductor molecules is the important issue for the improvement of charge carrier mobilities of organic field effect transistors. Tetrabenzoporphyrin (BP) is one of the promising p-type organic semiconductors but solubility in organic solvents is very low. We have developed a precursor approach, where a spun-cast film of soluble precursor, tetra-bicyclo[2.2.2]octadiene-fused porphyrin (CP), was heated to obtain BP crystalline film by in-situ retro-Diels–Alder reaction. However, the obtained BP film is a polycrystalline film and the field-effect transistors (FETs) hole mobilities were 10-1~10-2 cm2V-1s-1[1]. Recently, we reported the effect of alkyl substituents at 5,15-positions of BP for the control of the molecular arrangement. The best performance of OFET hole mobility of 5,15-disubstituted BP was 4.1 cm2V-1s-1 [2, 3].

A supramolecular strategy has attracted attentions as the effective method for the control of molecular arrangement in films. We applied the combination of supramolecular assembling method and the precursor approach to prepare well-ordered BP films. 5,15-Bis(p-dodecylamidephenyl)-CP was deposited on the substrate by drop-casting, spin-coating or dip-coating method, followed by the heating to 200 ºC for 10 min to give the corresponding 5,15-bis(p-dodecylamidephenyl)-BP films. The film morphologies of the BP were compared with 5,15-bis(p-dodecyloxyphenyl)-BP, which doesn’t include amide moieties for hydrogen-bonding, using UV-vis absorption spectroscopy, atomic force microscopy (AFM), X-ray diffraction (XRD) analysis, and p-polarized multiple-angle incidence resolution spectrometry (p-MAIRS) to clarify the effect of amide groups. OFET performance of the BPs will be also discussed to clarify the effect of intermolecular hydrogen bonding interaction.

References

[1] H. Yamada*, D. Kuzuhara, M. Suzuki, H. Hayashi, N. Aratani, Synthesis and Morphological Control of Organic Semiconducting Materials using the Precursor Approach, Bull. Chem. Soc. Jpn. 2020, 93, 1234-1267.

[2] K. Takahashi, B. Shan, X. Xu, S. Yang, T. Koganezawa, D. Kuzuhara, N. Aratani, M. Suzuki*, Q. Miao*, H. Yamada*, Engineering Thin Films of a Tetrabenzoporphyrin toward Efficient Charge-Carrier Transport: Selective Formation of a Brickwork Motif. ACS Appl. Mater. Interfaces 2017, 9, 8211-8218.

[3] E. Jeong, T. Ito, K. Takahashi, T. Koganezawa, H. Hayashi, N. Aratani, M. Suzuki*, H. Yamada*, Exploration of alkyl-group effects on the molecular packing of 5,15-disubstituted tetrabenzoporphyrins toward efficient charge-carrier transport. ACS Appl. Mater. Interfaces 2022, 14, 32319-32329.
Novel Functional Organic Chromophores
Authors: Hill Jonathan P.
Published: August 2024

Porphyrins and other tetrapyrroles are highly suitable for sensing operations based on their synthetic flexibility and chromophore structures where an analyte might interact to stimulate some variation in directly observable optical colour or fluorescence emission modulation. Their chromophore structures also allow access to electronic triplet states, which can be harnessed for the generation of singlet oxygen – a highly reactive species useful for photodynamic action against tumours or microorganisms. Here we discuss the sensing activity of several β-substituted porphyrins1 including not only by the introduction of suitable interacting units but also by the adaptation of non-planar porphyrins for the synthesis of porous structures. The latter are applied for film formation and sensing involving nanomechanical sensors. Selectivity and mechanisms of sensing activity are discussed. We will also introduce new efficient singlet oxygen generating materials based on agglomeration of an oxidized porphyrin chromophore as metal-organic frameworks,2 electron deficient porous polymers, or using resorcinarenes.3 The use of these materials for selective oxidation of organic substrates is demonstrated. Overall, the results demonstrate the efficacy of the chromophore approach to functional materials. The self-assembly properties of porphyrins and nitrogen rich acene compounds, the pyrazinacenes, will also be considered based on contrasting cases of on-surface mobility and immobility, and the introduction of particular functionality influencing the resulting supramolecular structures.

References: 1) M. K. Chahal, A. Liyanage, A. Z. Alsaleh, P. A. Karr, J. P. Hill and Francis D’Souza, Chem. Sci. 12, 4925-4930 (2021), 2) J. Hynek, D. T. Payne, M. K. Chahal, F. Sciortino, Y. Matsushita, L. K. Shrestha, K. Ariga, J. Labuta, Y. Yamauchi and J. P. Hill, Mater. Chem. Today 21, 100534 (2021), 3) C. Bloyet, F. Sciortino,Y. Matsushita, P. A. Karr, A. Liyanage, W. Jevasuwan, N. Fukata, S. Maji, J. Hynek, F. D’Souza, L. K. Shrestha, K. Ariga, T. Yamazaki, N. Shirahata, J. P. Hill and D. T. Payne, J. Am. Chem. Soc. 144, 10830-10843 (2022).
Synthesis and Characterization of Aromatic Heterocycle-Fused Porphyrins
Authors: Wang Hong , Arvidson Jacob , Shaikh Saaf , Kaswan Ram , Jang Youngwoo , Alsaleh Ajyal , D'Souza Francis
Published: August 2024

The advances in materials science increasingly demand novel functionalized materials. Porphyrins fused with aromatic moieties represent attractive largely π-extended structures, offering new opportunities in molecular and organic electronics.1-4 In this presentation, new synthetic methods to fuse different type of aromatic rings to the porphyrin periphery will be presented. These new methods have led to the synthesis of novel large π-extended molecular structures incorporating both porphyrins and other aromatic components including acenaphtho[1,2-b]pentacene-, acenaphtho[1,2-b]pentacene quinone, benzodithiophenes and cyclooctatetraenes. Unprecedented electronic and photophysical properties have discovered for these π-extended porphyrins. For example, an unusual trend was observed in the florescence quantum yield upon converting thiophene-attached benzoporphyrin to naphthodithiophene-fused porphyrin. A remarkable light effect was obtained with a acenaphtho[1,2-b]pentacene-fused porphyrin-phthalocyanine heterojunction device, which exhibited high ammonia sensitivity. The characterizations of these π-extended porphyrins including time-resolved emission and transient absorption spectroscopy, cyclic voltammetry, DFT calculations 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.

Washburn, R. Kaswan, S. Shaikh, A. Moss, F. D’Souza and Hong Wang, J. Phys. Chem. A., 2023,127 (43):9040-9051.

Cooper, A. Alsaleh, S. Kumar, W. Rackers, V. N. Nesterov, F. D’Souza, S. A. Vinogradov and H. Wang, Chem. Eur. J., 2023, e202302013.

Moss, Y. Jang, H. Wang, F. D’Souza, ChemSusChem, 2023, 16 (8), e202202289.
Correlative Microscopy Analysis for Battery Materials
Authors: Trenikhina Yulia , Kelly Stephen T , Tordoff Benjamin , Harris William
Published: August 2024

Lithium batteries (LB) are in high demand for a diverse range of applications, such as automotive industry, consumer electronics, wearable and medical devices, grid storage, etc. Each application demands a specific set of performance advantages, such as high capacity and/or energy density, long cycle life, superior electrochemical stability. Therefore, there is no one-size-fits-all for a LB chemistry and its form factor. Battery performance advantages rely on optimization of the battery components, including active materials, electrolyte, separator, binder system, and current collectors. For meaningful device optimization, electrochemical battery testing needs to be combined with a deep understanding of the material and device microstructure. Physical and chemical characterization on the material- and electrode-level is needed to establish root-cause relationships with battery performance. Properties of the interfaces between layers of the battery components often define the device characteristics. Critical information is usually buried beneath the surface of a material specimen or encapsulated in a closed-form device. Microstructural defect identification in the battery needs to be followed by a targeted defect study. Different battery form factors and chemistries make it hard to streamline root-cause analysis.

Recently, a commercial focused-ion beam scanning electron microscope was developed with an integrated fs-laser mill attached to the load lock of the microscope, opening the door to new and more powerful analysis approaches in energy materials research. Applications include rapid access to deeply buried structures for high resolution imaging and analytics, large area cross-section preparation, and massive material ablation for sample preparation of structures; e.g. FIB-SEM tomography, TEM, APT, or X-ray nanoCT. Additionally, each of these methods may be correlatively guided by prior imaging, with techniques like 3D X-ray microscopy (XRM), to enable targeted analysis and preparation. The non-destructive nature of 3D XRM makes it an ideal tool for microstructural defect identification in LB. Laser mill allows researchers to combine non-destructive X-ray defect identification with electron microscopy methods for targeted defect characterization. This approach can be used for various battery types and form factors.

By combining the laser mill with 3D X-ray microscopy, this platform enables comprehensive analysis of energy materials at the nanoscale. We illustrate these concepts with application examples, and use cases demonstrating the utility of the approach.
Battery Lifetime Prediction and Degradation Analysis with Machine Learning Method
Authors: Choi Jung-goo , Seo Gyuwon , Lee Jaeyoung
Published: August 2024

Due to environmental pollution and climate crisis caused by fossil fuels, eco-friendly alternative energy sources are gaining attention. Particularly, electric vehicles (EVs) are being recognized as the next-generation means of transportation. The most crucial technologies in electric vehicles are lithium-ion batteries and Battery Management Systems (BMS). However, the extended lifespan of lithium-ion batteries leads to prolonged assessment periods, making it challenging to measure and improve performance over time. Additionally, the operation of batteries under various conditions makes it difficult to measure state of charge (SOC) and state of health (SOH) in real-time, introducing many variables. With recent advancements in predictive technology through machine learning, accurate predictions can be made without complex physical knowledge, leveraging high-quality data.

In this study, machine learning techniques were applied using charge/discharge data from lithium-ion LiNi0.5Mn0.3Co0.2O2 (NMC532)/graphite pouch cell batteries. The values measured during the initial charge/discharge cycles were converted into variables that could assess battery degradation modes. Machine learning algorithms were then applied, followed by model tuning to reduce overfitting and enhance accuracy. This research contributes to real-time battery management system data using machine learning technology to predict the remaining useful life (RUL) of lithium-ion batteries with high accuracy, using only initial cycles. This approach enhances the efficiency of BMS data in real-world scenarios and contributes to the overall time efficiency of battery research.

Acknowledgement

This research was supported by National R&D Program through the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT(NRF-2021K1A4A8A01079455).
W(h)Ither Fullerenes in Medicine? Challenges and Opportunities in Industrial Translation
Authors: Rasovic Ilija
Published: August 2024

The fullerenes—C60 and its derivatives in particular—have been lauded for three decades now as having revolutionary potential for next-generation medical applications. These span therapeutics (e.g. enzyme inhibition and photodynamic therapy for treating cancers) and diagnostics (e.g. improved contrast agents for magnetic resonance imaging). But translating this potential beyond academic research studies and into scaled-up production and clinical practice has proved far more elusive than the much-sought-after widespread industrial adoption of graphene.

In this talk I will first outline why the fullerenes do indeed offer such promise in these clinical application areas, before providing an exploration of many of the intersecting factors that have contributed to making the clinical translation of fullerene-based therapeutics and diagnostics such a seemingly insurmountable barrier up to this point. These factors include:

A uniquely multi-dimensional chemical design space when considering fullerene size and both exohedral and endohedral functionalisation possibilities;

The relationship of the above with understanding functionality and safety in vivo;

Regulatory requirements pertaining to the above;

The presence of unregulated fullerene-based products in the beauty and wellness sector;

The fuzzy borderlands between science and pseudoscience that much of the narrative around fullerenes occupies;

Loss of funding momentum;

Lack of industrial bridges between materials manufacturers and technology developers.

After characterising the state of affairs in this way, I will offer some specific suggestions for hope and opportunity as we move into a world where synthesis and testing bottlenecks can be overcome with the help of artificial intelligence and automation, and increased awareness of the diverse properties of different types of nanomaterials changes the regulatory and industrial landscapes. Thus, I hope to provide a case study of how one family of carbon nanomaterials could finally realise its promise of advancing medicine in the Industry 4.0 era.
The Role of Electrolyte Composition in Enhancing the Performance of Graphene Batteries
Authors: Bekyarova Elena
Published: August 2024

Graphene is a promising anode material for the next generation batteries. Understanding the interactions of the graphene surface with common and novel electrolyte solvents and additives is important in improving the overall electrochemical performance of lithium-ion batteries. Electrolyte additives play important role in the formation of solid-electrolyte interface (SEI) on the anode surface and can increase the capacity and cycling stability of the battery. This presentation will discuss the design strategy of electrolyte formulations for long-cycle high-energy graphene-based batteries and report results on the cycling stability of the graphene batteries for Low Earth Orbit satellites.
First Isolation of Solvated MgCl+ species as the Sole Cations in Electrolyte Solutions for Rechargeable Mg Batteries
Authors: Maddegalla Ananya , Kumar Yogendra , Chakrabarty Sankalpita , Glavgosky Yuri , Schmerling Bruria , Fridman Natalia , Afri Michal , Aviv Hagit , Aurbach Doron , Mukherjee Ayan , Bravo‐Zhivotovskii Dmitry , Noked Malachi
Published: August 2024

Synthesis of complex magnesium cations in ethereal solutions, is receiving a lot of attention due to their potential utilization in rechargeable magnesium batteries (RMB). The simplest complex cation, namely, solvated MgCl+, was hypothesized and reported as the most important cation in nonaqueous magnesium electrolyte solutions chemistry. However, such ions have never isolated as the only cationic species in ethereal solutions developed for RMB. In this study, we report on a successful isolation of the pure electrolyte MgCl(THF)5
+ - PhAlCl3
- , and on the electrochemical behaviour of its ethereal solutions. The structure of this compound was proved by single-crystal X-ray diffraction, Raman, and, NMR spectroscopies. The novel MgCl(THF)5PhAlCl3/THF electrolyte solutions exhibit reversible Mg deposition/dissolution processes with anodic stability up to 2.7 V. The application of electrochemical cleaning pre-treatment for these solutions enabled to profoundly increase the coulombic efficiency of their Mg deposition/dissolution processes. Examining Mg prototype batteries with Mg foil anodes, composite MgxMo6S8Chevrel phase (CP) cathodes containing these solutions exhibited a viable battery performance, indicating that upon a further optimization, electrolyte solutions based on the complex MgCl(THF)5
+ - PhAlCl3
- electrolyte may be suitable for practical RMB.

Figure 1
Simulating the Effects of Ammonia Crossover and Alternative Ligands in Thermally Regenerative Flow Batteries
Authors: Cross Nicholas R. , Rau Matthew J , Gorski Christopher A. , Logan Bruce E. , Hall Derek M.
Published: August 2024

There is a significant amount of low-temperature heat (< 100 °C) available globally from various sources such as geothermal energy, industrial processes, and thermal power plants. Electrochemical and membrane-based methods for harnessing this heat are becoming of greater interest due to their ability to utilize the low temperature energy sources and because they can be sized modularly to fit the power, energy, and spatial requirements of the application. The all-aqueous thermally regenerative ammonia battery (Cuaq-TRAB) is a leading technology in the waste heat to electrical power production space due to recent results showing operational power densities of 25 mW cm-2 with an estimated thermal energy efficiency of 7%, outperforming most technologies in this space. Previous research on the Cuaq-TRAB has shown that the battery suffers from the crossover of ammonia through the membrane which adversely impacts battery performance.

To investigate these impacts, we developed a simple numerical model that simulates discharge curves using one fitting parameter to account for parasitic crossover instead of modeling species transport through the membrane. The model was able to replicate experimental data from Cuaq-TRABs with different membrane materials and for multiple applied current densities with < 5% error for average power and energy capacity. Results showed that there is a 20% loss in Cuaq-TRAB energy capacity due to ammonia crossover when compared to a discharge with no parasitic crossover losses. The model was then extended to demonstrate the impact of different changes to the electrolyte chemistry on the resultant power and energy capacities for Cuaq-TRABs. Using this model, we estimate that if chloride was the ligand for the positive electrolyte instead of bromide, it would decrease the power and energy capacity of the battery by 30%. However, considering that an economic analysis showed that chloride is 80% cheaper than bromide, it may be beneficial to consider the use of chloride ligands in this technology despite its worse electrochemical performance.
Advancing Structural Supercapacitors with Hydrated Polymer
Authors: Teymoory Parya , Chang Yu-Che , Shen Caiwei
Published: August 2024

Structural supercapacitors, capable of bearing mechanical loads while storing electrical energy, hold great promise for enhancing mobile system efficiencies. However, developing practical structural supercapacitors often involves a challenging balance between mechanical and electrochemical performance, particularly in their electrolytes. Traditional research has focused on bi-continuous phase electrolytes (BPEs), which typically comprise high liquid content that weakens mechanical strength, and inert solid phases that hinder ion conduction and block electrode surfaces. Our previous work introduces a novel approach with a hydrated polymer electrolyte, demonstrating enhanced multifunctionality. This electrolyte, derived from controlled hydration of PET-LiClO4, forms a trihydrate (LiClO4∙3H2O) structure, where water molecules bond with ions without forming a liquid phase, thereby improving ion mobility while maintaining the base polymer's mechanical properties. This new design also promotes better electrochemical interfaces with electrodes, a significant advancement over traditional BPEs.

In this study, we further enhance the performance and processability of such hydrated polymer electrolytes by incorporating polylactic acid (PLA) as the base polymer and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as the salt. The electrolyte, prepared through solution casting and subsequent controlled hydration, consistently remains an amorphous solid solution in both dry and hydrated states, as confirmed by DSC, XRD, and FTIR analyses. Our tests on ionic conductivity and mechanical properties reveal that adding water to the polymer electrolyte substantially increases ionic conductivity while retaining mechanical properties. A specific composition demonstrated a remarkable increase in ionic conductivity coupled with superior toughness surpassing the base polymer. Furthermore, we successfully fabricated and tested structural supercapacitor devices made of composites of carbon fibers and these new electrolytes. The prototypes presented enhanced toughness with significant energy storage performance, demonstrating their vast application potential due to their outstanding multifunctionality.
Exploring New Carbon Allotropes and Nanographenes on Surfaces
Authors: Gottfried Michael
Published: August 2024

The quest for planar sp2-hybridized carbon allotropes other than graphene has stimulated substantial research efforts because of their predicted unique mechanical, electronic, and transport properties. However, the syntheses of these nonbenzenoid networks remain challenging due to the lack of reliable protocols for generating nonhexagonal rings. We have developed various on-surface synthesis strategies by which straight polymer chains are linked to form the nonbenzenoid carbon networks. In this way, we synthesized biphenylene network, a new carbon allotrope with 4-6-8-membered rings, which is metallic already at very small dimensions. Similarly, we generated phagraphene nanoribbons, which are based on 5-6-7-membered rings.

Acenes are another interesting class of carbon materials that have fascinated chemists and physicists due to their potential for use in organic electronic applications. We show the synthesis of tridecacene (13ac) and pentadecacene (15ac), the longest acenes known to date, via multistep single-molecule manipulation of suitable precursor molecules on Au(111). We find antiferromagnetic open-shell ground state electron configurations for both acenes. 15ac shows a low-bias spin-excitation feature, indicating a singlet-triplet gap of around 124 meV. Investigation of 15ac complexes with up to 6 gold atoms suggest considerable multiradical contributions to the electronic ground state of 15ac.

Altering the electronic and magnetic properties of carbon-based nanomaterials can also be achieved by doping with heteroatoms. We present an access to a variety of nitrogen-containing 0D and 1D carbon nanostructures including planar and curved cycloarenes with different cavities as well as N-doped graphene nanoribbons.
On-Surface Synthesis of 2D Polymers at the Liquid-Solid Interface
Authors: De Feyter Steven
Published: August 2024

Unraveling the structure and dynamics of the formation of covalent and non-covalent organic-based 2D crystalline materials is key to controlling the quality of these materials, such as the defect density and their size. Understanding these characteristics is important for controlling their properties. This contribution highlights our efforts in using scanning probe microscopy, particularly scanning tunneling microscopy (STM), to visualize the structure and dynamics of substrate-supported metal-organic frameworks (sMOFs) and substrate-supported covalent organic frameworks (sCOFs) at the liquid-solid interface.

We will focus on the growth of covalent organic frameworks, primarily based on boroxine chemistry, and reveal both qualitative and quantitative details of the nucleation-elongation processes in real-time and under ambient conditions. Sequential data analysis enables the observation of the amorphous-to-crystalline transition, the time-dependent evolution of nuclei, the existence of 'non-classical' crystallization pathways, and, importantly, the experimental determination of essential crystallization parameters with excellent accuracy, including critical nucleus size, nucleation rate, and growth rate. Other aspects that will be addressed include sCOFs and chirality, as well as the formation of multilayered sCOFs.

Additionally, we demonstrate that in specific cases, the electric field between the STM tip and the substrate can induce, on demand, the polymerization or depolymerization process.
Exploring Order/Disorder Molecular Networks on Metal Surfaces
Authors: Lu Jiayi , Zheng Fengru , Jiang Hao , Zhu Zhiwen , Yan Yuyi , Nieckarz Damian , Szabelski Paweł , Sun Qiang
Published: August 2024

Materials featuring disordered structures often exhibit unique properties. Metal-organic frameworks (MOFs) are a class of hybrid materials composed of metal nodes and coordinating organic linkers[1]. Recently, there has been growing interests in MOFs with structural disorder, and the investigations of amorphous structures on surfaces[2]. Herein, we demonstrate a bottom-up method to construct molecular networks on metal surfaces with order-disorder transition by preparing two-component samples with different stoichiometric ratios of two organic molecule linkers sharing the same symmetry but differing in size[3]. We investigate the topological and electronic structures of the order/disorder molecular networks by scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) under ultra-high vacuum (UHV). The results may advance our understanding of the formation mechanism and electronic behaviors characteristic of monolayer molecular networks with structural disorders, holding the potential to catalyze advancements in the design and application of new amorphous MOF materials with intriguing properties.

[1] L. Dong, et al., Progress in Surface Science, 91, 101–135 (2016).

[2] J. Fonseca, et al., Journal of Materials Chemistry A, 9.17, 10562-10611 (2021).

[3] J. Lu, et al., ACS Nano, 17, 20, 20194–20202 (2023).
Gem-Dibromovinylenes: Highly Versatile Systems for On-Surface Synthesis
Authors: Martin Nazario
Published: August 2024

The advent of the so-called On-Surface synthesis represents a new scenario where testing new reaction conditions affording disruptive materials impossible to be obtained by conventional synthetic chemistry. In this regard, we have reported an unprecedented chemical reaction from tetrabromo-p-quinodimethanes (TBQs) which, by heating on gold surface, has allowed to obtain a variety of new 1D π-conjugated polymers,[1] some of them exhibiting a quasimetallic behavior.[2]

In this presentation, new designed organic molecules endowed with gem-dibromovinylene units have been synthesized with the aim of broadening the scope of this highly reactive functional group to other on-surface chemical reactions.[3] Thus, new different polymers or molecular systems will be presented and discussed.[4]

References

[1] A. Sánchez-Grande, et al., "On-surface synthesis of ethynylene bridged anthracene polymers", Angew.
Chem. Int. Ed., 2019, 58, 6559-6563.

[2] Cirera, B., et al., “Tailoring topological order and π-conjugation to engineer quasi-metallic polymers”. Nat. Nanotechnol.
2020, 15, 437–443.

[3] Sánchez-Grande, et al., "Surface-assisted Synthesis of N-substituted π-Conjugated Polymers" Adv. Sci., 2022, - advs.202200407R1

[4] E. Pérez-Elvira, et al., "Generating Antiaromaticity: Thermally-selective Skeletal Rearrangements at Interfaces", Nat. Synth., 2023, NATSYNTH-22121246B.
Engineering Topological States in 1D Pi-Conjugated Polymers
Authors: Ecija David
Published: August 2024

The emergence of topological states is at the vanguard of modern condensed matter physics. In this talk, I will revise our recent findings regarding the expression of topological SSH edge states on 1D acene and periacene pi-conjugated polymers. Importantly, thanks to the resolution capabilities provided by scanning probe microscopies, complemented by theory, I will provide the relation between the dominant resonant form and the topological quantum class of the distinct materials.
Synthetic Electronics
Authors: Baatar Chagaan
Published: August 2024

Building electronic circuitry with atomic precision is beyond the capability of current, as well as in the foreseeable future, top-down lithographic techniques. In recent years, the US Office of Naval Research (ONR) has championed several research initiatives that sought to address this key challenge. One of the most exciting development and initial success that resulted from these initiatives is a bottom-up chemical synthesis technique that has proven highly effective at assembling two-dimensional (2D) graphene nanostructures with spatial resolution down to single atom and single bond level. In this presentation I will briefly review, from a government program manager perspective, the current status of this exciting new research field which I call Synthetic Electronics. I will highlight some recent technical and scientific advances, such as various on-surface synthesis techniques, that enable and help define future directions of synthetic electronics. I will share some of my own personal perspectives and speculate on possible future directions, and also draw attention to some of the major challenges that are facing synthetic electronics. The motivation behind the discussion is to socialize the basic ideas and capabilities with, and seek feedback from, the relevant research communities, in order to inform and further refine research agenda in the future.
Syntheses of Heteroatom-Substituted and Three-Dimensional Nanocarbon Materials on Surfaces
Authors: Kawai Shigeki
Published: August 2024

I will present our recent studies on on-surface chemistry with high-resolution scanning probe microscopy operating at low temperature under ultra-high vacuum. We synthesized three-dimensional organometallic compound and graphene nanoribbon by coupling hexabromo substituted-propellane molecules on Au(111) and Ag(111).[1] In the structure, the C-Br bonds distant from the surface remained intact even after the reaction. The radical species were formed by tip-induced debromination and were also stabilized by either tip-manipulated Br atom or fullerene molecule. We also demonstrate systematic tip-induced isomerization via embedding a text of “NIMS” by following binary and ternary ascii cords, in which two chiral dehydroazulene and diradical units were used.[2] Among the three states, the diradical unit showed the spin coupling of 90 meV. For heteroatom substitution, we developed an on-surface reaction, which can synthesize graphene nanoribbon and covalent organic frameworks with silabenzene units by coupling Si atom and Br-substituted molecule.[3] The heavier congeners of cyclic aromatic compounds have been studied as an elusive target product for organic synthesis due to their high reactivity at ambient temperature and difficult isolation. Thus, this result shows the advantage of on-surface synthesis.

Reference

[1] S. Kawai, et al Sci. Adv. 6, eaay8913 (2020).

[2] S. Kawai, et al Nat. Commun. 14, 7741 (2023).

[3] K. Sun et al, Nat. Chem. 15, 136 (2023).
On-Surface Synthesis of 2D Radical Frameworks
Authors: Sanchez-Grande Ana , Frezza Federico , Matej Adam , Carrera Manuel , Stetsovych Oleksandr , Kumar Manish , Mutombo Pingo , Curiel David , Jelínek Pavel
Published: August 2024

The design of atom thick two-dimensional (2D) frameworks by on-surface synthesis has recently contributed to the development of advanced materials with high control over their structural, electronic, optical and magnetic properties. Countless 2D frameworks, with a large variety of applications, can be synthesized made of purely organic molecules (covalent organic and supramolecular frameworks) or combining both metals and organic molecules (metalorganic frameworks). Here, we focus on the design and synthesis of radical 2D frameworks, composed of open-shell nanographenes equipped with azaindole units, on an Au(111) surface. Interestingly, the deposition of transition metal atoms on such frameworks allow the tuning of their magnetic properties, expanding their possible applications. The structural, electronic and magnetic characterization of the frameworks was performed by scanning tunneling microscopy/spectroscopy (STM/STS) and non-contact atomic force microscopy, and supported by density functional theory (DFT) calculations. Additionally, the magnetic characterization was complemented by nickelocene-functionalized tips investigations, which act as a magnetic sensor that unveils the magnetism of the frameworks at the single molecule level.
Fabrication of Novel Carbon-based Polymers by On-surface Cycloaromatization of Isopropyl Substituents
Authors: Urgel Jose , Biswas Kalyan , Urbani Maxence , Kinikar Amogh , Pérez Elvira Elena , Barragán Ana , Di Giovannantonio Marco , Soler Diego , Ruffieux Pascal , Fasel Roman , Jelínek Pavel , Torres Tomas , Ecija David
Published: August 2024

Surface-catalyzed reactions have been employed for the synthesis of carbon nanomaterials featuring precisely defined atomic structures. A recent breakthrough involves the gold surface-catalyzed [3 + 3] cycloaromatization of isopropyl-substituted arenes, allowing for on-surface synthesis of novel carbon-based polymers[1-3]. In this process, the surface plays a crucial role in activating the isopropyl substituents, facilitating the formation of phenylene rings through intermolecular coupling. For instance, such investigations might open new avenues in the field of carbon magnetism, which has gained an increased attention in view of the recent progress made in the synthesis and characterization of open-shell polycyclic aromatic hydrocarbons[2]. Under this scenario, the comprehensive fabrication of magnetic polymers emerges as a highly appealing field of research.

Here, we introduce exemplary approaches toward the bottom-up fabrication of different carbon-based polymers homocoupled via surface-catalyzed [3 + 3] cycloaromatization of isopropyl substituents studied on Au(111) under ultra-high vacuum (UHV) conditions. The chemical structures of the polymers have been clearly elucidated by non-contact atomic force microscopy (nc-AFM). Scanning tunneling spectroscopy (STS), complemented by computational investigations reveals their ground state. Our approach can be a highly relevant step towards the on-surface synthesis of covalently linked 1D organic polymers with prospects in sensing, catalysis and nanoscale spintronic devices.

References:

1 - Kinikar, A. et al. (2022). On-surface polyarylene synthesis by cycloaromatization of isopropyl substituents. Nature Synthesis, 1(4), 289-296.

2 - Biswas, K., et al. (2022). Interplay between π-Conjugation and Exchange Magnetism in One-Dimensional Porphyrinoid Polymers. Journal of the American Chemical Society, 144(28), 12725-12731.

3 - Kinikar, A. et al. (2023). Sterically Selective [3 + 3] Cycloaromatization in the On-Surface Synthesis of Nanographenes. ACS Nanoscience Au.

Figure 1
Anhydride Photolysis on a Semiconductor Surface
Authors: Frezza Federico , Sanchez-Grande Ana , Canola Sofia , Mutombo Pingo , Chen Qifan , Ernst Karl-Heinz , Wäckerlin Christian , Di Giovannantonio Marco , Nachtigallová Dana , Jelínek Pavel
Published: August 2024

The on-surface synthesis (OSS) method has facilitated the growth of diverse carbon-based nanomaterials, with the goal of integrating them into electronic devices. However, the reliance on metallic substrates in OSS restricts these materials' applications, necessitating strategies for transferring these materials into technological relevant substrates or direct synthesis on non-metallic surfaces, where the low absorption energies and lack of catalytic activity from the substrate complicate this approach. Addressing these limitations, we explore on-surface photochemistry as an alternative to thermally induced reactions, enabling controlled chemical processes at lower temperatures. While prior works have demonstrated light-induced reactions on metallic surfaces, where the hot electrons photogenerated from the metallic surface play a crucial role, synthesizing nanostructures directly on semiconducting or insulating surfaces through a purely intramolecular energy absorption remains challenging.

The photolysis and pyrolysis of anhydrides has proven to be a suitable approach for the formation of arynes, as schematically shown in the Figure. Our study focuses on the selective photodissociation of maleic anhydride-containing precursors on a semiconductor surface (SnSe), unveiling their distinct photochemical behaviors. Specifically, tetraphenylphthalic anhydride (TPPA) undergoes successful photolysis on SnSe, forming tetraphenyl benzyne (TPBY) intermediates, and eventually, tetraphenyl benzene (TPBE) products. Furthermore, TPPA photolysis occurs efficiently also at room temperature, leading to the direct formation of TPBE. Contrastingly, benzo[ghi]perylene-1,2-dicarboxylic anhydride (BPA) possesses an extended pi-conjugated backbone and exhibits no photoactivity upon irradiation on the same semiconductor surface. Our calculations of TPPA and BPA excited states predict different behaviors, demonstrating the relationship between molecular structure, pi-conjugation, and photochemical reactivity, offering insights into the design principles for light-induced reactions on inert surfaces.

Figure 1
Topology Selectivity of a Conformationally Flexible Precursor by Selenium Doping
Authors: CAI Liangliang , Wee Andrew
Published: August 2024

Conformational arrangements within nanostructures play a crucial role in shaping the overall configuration and determining the properties, for example in covalent/metal organic framework (COF/MOF) synthesis. In on-surface synthesis, conformational diversity often leads to uncontrollable or disordered structures. Therefore, exploration on controlling and directing the conformational arrangements is significant in achieving desired nanoarchitectures. In this study, a conformationally flexible precursor 2,4,6-tris(3-bromophenyl)-1,3,5-triazine (mTBPT) was employed, and a random phase consisting of C3h
and Cs
conformers was first obtained after deposition of mTBPT on Cu(111) from room temperature (RT) to ~365 K as expected. By low coverage (0.01 ML) selenium (Se) doping, we achieved the selectivity of the C3h
conformer greatly and improved the nanopore structural homogeneity. The ordered 2D metal organic nanostructure from mTBPT could be fulfilled by Se doping from RT to ~365 K, and the deposition sequence of mTBPT and Se did not make any difference. Through the combination of high-resolution scanning tunneling microscopy and non-contact atomic force microscopy, we explored the regulation of the conformationally flexible mTBPT on Cu(111) and achieved the high topology selectivity by low coverage Se doping. Density functional theory calculations revealed the energy regulation of organometallics before and after Se doping at atomic level. These results could enrich the on-surface synthesis toolbox of conformationally flexible precursors, for the design of complex nanoarchitectures, and for future development of engineered nanomaterials and nanodevices.

Figure 1
On-Surface Synthesis of Open-Shell Nanographenes through the π-Extension of Dibenzo[Hi,St]Ovalene
Authors: Narita Akimitsu
Published: August 2024

Graphene nanostructures are attracting attentions for their intriguing optical, electronic, and magnetic properties that are critically dependent on their chemical structures. Whereas it is challenging to obtain atomically precise structures by typical top-down fabrication methods, such as lithographic patterning of graphene and unzipping of carbon nanotubes, bottom-up synthesis enables the preparation of molecular nanographenes and graphene nanoribbons (GNRs) with pre-designed structures. In addition to the solution synthesis based on the methods of synthetic organic chemistry, such graphene nanostructures can also be synthesized on metal surfaces under ultrahigh vacuum conditions and directly visualized by atomic resolution scanning probe microscopy (SPM) [1]. Using carefully designed and solution-synthesized molecular precursors, this on-surface synthesis method can provide various nanographenes, including the structures that are highly unstable under ambient conditions. We have previously developed the solution synthesis of dibenzo[hi,st]ovalene (DBOV) with strong red fluorescence [2], and achieved its π-extension to circumpyrene [3]. Following the successful synthesis of rhombus-shaped nanographenes with four zigzag edges, showing a closed-shell or an open-shell depending on the size [4], we functionalized DBOV and circumpyrene with two 2,6-dimethylphenyl groups for their on-surface π-extension to unprecedented zigzag-edged nanographenes. The resulting structures were clearly visualized by scanning tunneling microcopy and their open-shell characters were indicated by theoretical and experimental investigations, revealing large magnetic exchange couplings of up to 190 meV [5]. We have more recently also achieved further π-extension of these open-shell nanographenes on surface and obtained initial results for their polymerization.

[1] Chen, Z.; Narita, A.; Müllen, K.; Adv. Mater.
2020, 32, 2001893.

[2] Paternò, G. M.; Chen, Q.; Wang, X.-Y.; Liu, J.; Motti, S. G.; Petrozza, A.; Feng, X.; Lanzani, G.; Müllen, K.; Narita, A.; Scotognella, F., Angew. Chem. Int. Ed.
2017,
56, 6753–6757.

[3] Chen, Q.; Schollmeyer, D.; Müllen, K.; Narita, A., J. Am. Chem. Soc.
2019, 141, 19994–19999.

[4] Mishra, S.; Yao, X.; Chen, Q.; Eimre, K.; Gröning, O.; Ortiz, R.; Di Giovannantonio, M.; Sancho-García, J. C.; Fernández-Rossier, J.; Pignedoli, C. A.; Müllen, K.; Ruffieux, P.; Narita, A.; Fasel, R.; Nat.
Chem. 2021, 13, 581.

[5] Biswas, K.; Soler, D.; Mishra, S.; Chen, Q.; Yao, X.; Sánchez-Grande, A.; Eimre, K.; Mutombo, P.; Martín-Fuentes, C.; Lauwaet, K.; Gallego, J. M.; Ruffieux, P.; Pignedoli, C. A.; Müllen, K.; Miranda, R.; Urgel, J. I.; Narita, A.; Fasel, R.; Jelínek, P.; Écija, D. J. Am. Chem. Soc. 2023, 145, 2968–2974.
Electrodeposition of WO3 Nanoparticles Onto a Carbon Membrane Surface for the Development of a Hybrid Filtration/Photocatalysis System
Authors: Boldrin Zanoni Maria Valnice , Rojas-Mantilla Hernán Dario , Irikura Kallyni , Souza João Carlos Carlos , Ayala-Durán Saidy Cristina , Lima Gomes Paulo Clairmont Feitosa de , Salazar Ricardo
Published: August 2024

This study proposes the development of a photoactive filtration membrane using carbon fiber (CF) modified with an n-type semiconductor (WO3) to create a hybrid filtration/photocatalysis system applied in water treatment for simultaneous retention and degradation of the emerging contaminant (Sertraline - SER). The membrane was prepared through chemical electrodeposition in a three-electrode electrochemical cell, utilizing CF as the working electrode, two-dimensionally stable anode counter electrodes (De Nora), and an Ag/AgCl 4.0 mol L-1 KCl reference electrode. The preparation conditions included: 5.0 mmol L-1 of Na2WO4, 0.075% (v/v) H2O2, pH 1.4, with a potential of -0.5 V applied for 1 h, followed by heat treatment at 450 °C.

Characterizations revealed a mesoporous structure, with UV-Vis absorption (300 - 700 nm), a band gap of 3.6 eV, and a BET surface area of 3.1 m2 g-1. Micrographs illustrated the formation of a uniform layer of WO3 on the CF surface, and characteristic peaks of C and WO3 in the monoclinic phase were confirmed. XPS analysis assigned species, including C 1s, O 1s, W (4f, 4f7/2, 4d5/2 4d3/2), with an intense peak at 530 eV related to the metallic bond (W-O).

The optimized experimental conditions: SER 2.0 mg L-1, volume 100 mL, flow rate 180 mL min-1, pH 5.6, UV LED irradiation, complete removal of SER was observed in 30 min when applied to real effluents from a water treatment plant before and after the chlorination step. Additionally, complete degradation was achieved after 90 min of the experiment in simulated effluents in Milli-Q water. The photoactive membrane proved effective under various conditions, achieving 1.41 mg L-1 SER degradation after five reuse cycles and complete SER degradation after 40 min under solar irradiation. Experiments with scavenger agents confirmed the participation of species (HO•, O2
•-, 1O2, h+, and H2O2) in the degradation process. Additionally, six degradation products were identified with mass-charge (m/z) of 176, 189, 191, 273, 293, and 322, generated from hydroxylation, demethylation, and dechlorination reactions.

The photoactive membrane has shown excellent potential for applications in filtration processes, mitigating issues associated with fouling. It facilitates the rapid removal and effective degradation of pollutants while also allowing for its application under various irradiation conditions. This feature simplifies and enables effective management in the treatment of contaminated waters.
(Digital Presentation) Synthesis of Carbon Materials on Aluminum Foil from a Vapor-Gas Environment
Authors: Kuzmina Elena , Barkov Alexey , Mishinkin Vadim , Kolosnitsyn Vladimir
Published: August 2024

Due to its excellent electrical conductive properties and large specific surface area, one of the allotropic modifications of carbon, carbon nanotubes (CNTs), grown on a metal substrate, have great potential for use in supercapacitor electrodes. After all, growing layers of nanotubes directly on the surface of electrodes. can make it possible to achieve the best adhesion and electrical contact of CNTs with the current collector [1]. The large surface area and exceptional electronic conductivity of CNTs make them prime candidates for high-performance and high-speed electrochemical applications [2].

The aim of the work was to investigate the effect of synthesis conditions on the structure and properties of a carbon layer grown on the surface of aluminum foil.

We used technical aluminum foil with a thickness of 16 microns. Aluminum foil was previously degreased with acetone, kept in an aqueous 1 M NaOH solution for 3 minutes and 30 minutes in a 20% aqueous solution of nickel nitrate at 90 °C. The synthesis of carbon materials on the surface of aluminum foil was carried out by pyrolysis of ethanol vapor in argon at 550 and 600 °C.

Analysis of SEM picture (fig. a) and Raman spectrum (dig. b) allows to conclude that the synthesized carbon materials are nanotubes or nanofibers.

It has been established that pre-treatment of aluminum foil with acetone does not affect the properties and uniformity of distribution of the carbon layer. On aluminum foil, without pretreatment and kept in acetone, after the synthesis of carbon materials from the vapor-gas phase, initial sections of aluminum foil without a carbon layer are observed. Preliminary exposure of aluminum foil in an alkali solution contributed to the uniform distribution of the synthesized carbon; the entire foil was evenly covered with carbon.

When pyrolysis of ethanol vapor is carried out in argon at 550 °C, the carbon layer is heterogeneous (fig. c) and volumetric growths are observed on the foil. When synthesizing carbon materials at 600°C, the carbon layer is dense without bulky formations (fig. d).

This work was performed as part of the Ministry of Science and Higher Education of the Russian Federation

[Government Order Theme No. 121111900148-3].

References

Redkin, A. N., Mitina, A. A., & Yakimov, E. E. (2021). Simple technique of multiwalled carbon nanotubes growth on aluminum foil for supercapacitors. Materials Science and Engineering: B, 272, 115342. DOI:10.1016/j.mseb.2021.115342;

Moyer-Vanderburgh, K., Ma M. C., Park, S.J., Jue, N.L., Buchsbaum, S.F., Wu K.J., Wood, M., Ye, J. Fornasiero, F., Growth and Performance of High-Quality SWCNT Forests on Inconel Foils as Lithium-Ion Battery Anodes: ACS Appl. Mater. Interfaces 2022, 14, 49, 54981–54991. DOI: 10.1021/acsami.2c18396

Figure 1