bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radical Reactions Enabled By Porphyrinoids
Authors: Gryko Dorota 
Published: July 2022

“
Look deep into
nature
, and then you will understand everything better.”

Albert Einstein

Porphyrinoids, also known as the pigments of life, are a class of naturally occurring organic dyes. They play key roles in crucial processes that support life - oxygen transport (hem), electron transport (cytochrome c), photosynthesis (chlorophyll a), and synthesis of DNA (vitamin B12). Vitamin B12 - a co-factor in many catalytic processes. Following nature, we have been exploiting the potential of this compound in catalysis.
Vitamin B12 - catalysis has been successfully translated into the laboratory and used in a small collection of reactions.[1-2] The advantage of using vitamin B12 as a catalyst lays in the complete stability of the central cobalt ion and by the definition it is nontoxic. It has also been well documented that the reaction mechanism usually follows a radical pathway, bringing a new dimension to this already interesting field.[2]

Along this line, we have developed new vitamin B12-catalyzed reactions involving reduction of Co(III) to Co(I) or Co(II) and subsequent reactions with electrophiles or radicals. Vitamin B12 derivative unusually catalyzes a new olefinic sp2 C-H alkylation reaction with diazo reagents as a carbene source,[3], acylation of activated olefins, alkylation of strained molecules.[4-6] These key findings emphasize the unique feature of vitamin B12 as a catalyst to achieve something unachievable with other methodologies or to find a greener approach.

References

[1] Banerjee, R. Chemistry and Biochemistry of B12, John Wiley & Sons, Inc, 1999

[2] Giedyk, M., Goliszewska, K., Gryko, D. Soc. Rev.
2015, 44, 3391-3404.

[3] Giedyk, M.; Fedosov, S.; Gryko, D. Commun.
2014, 50, 4674-4676.

[4] Ociepa, A. J. Wierzba, J. Turkowska, D. Gryko, J. Am. Chem. Soc.
2020, 142, 5355-5361.

[5] Potrząsaj, A.; Musiejuk, M.; Chaładaj, W.; Giedyk, M; Gryko, D ChemRxiv, 2021, 143, 9368–9376. https://doi.org/10.26434/chemrxiv.13559852.v1

[6] Turkowska, J.; Durka, J.; Ociepa, M.; Gryko, D. Chem.
Commun., 2021, DOI https://doi.org/10.1039/D1CC05330B

Figure 1
Metallomacrocycle-Derived Atomically Dispersed Metal Electrocatalysts with Controlled Selectivity for Small Molecule Conversion Reactions
Authors: Joo Sang Hoon 
Published: July 2022

Atomically dispersed metal catalysts or single-atom catalysts have recently emerged as a new frontier in the field of catalysis. They exhibit extreme atom efficiency and unusual catalytic activity and selectivity, which are hard to be attained with nanoparticle-based concentional catalysts. In this talk, we present metallomacrocyclic compound-driven syntheses of carbon supported atomically dispersed metal (M–N/C) catalysts toward selective small molecule conversion reactions, including oxygen reduction reaction reaction (ORR), CO2 reduction reaction (CO2RR), and chlorine evolution reaction (CER) [1-5]. The M–N/C catalysts provide unique catalytic selectivity in these reactions. For the ORR, tuning of metal type can direct the reaction pathway with Fe–N/C catalyzing the ORR via the four-electron (4e–) reduction to generate water (H2O) [1,2] whereas Co–N/C exhibiting preferred 2e– pathway to produce hydrogen peroxide (H2O2) [3,4]. In the CO2RR, Ni–N/C selectively reduces CO2 to CO while suppressing parasitic hydrogen evolution reaction [5]. For the CER, Pt–N/C catalyst is capable of catalyzing the CER with very high selectivity approaching 100% without competitive oxygen evolution reaction, even under low concentration of Cl– and neutral electrolyte, where OER is favored [6,7]. In contrast, traditional mixed metal oxide catalysts show substantially low CER selectivity. For the selective ORR and CER, in situ X-ray absorption spectroscopy combined with other spectroscopic techniques and density functional theory calculations have played a pivotal role in identifying the active sites and uncovering reaction kinetics and mechanisms.
References

J. Sa et al., J. Am. Chem. Soc. 138, 15046 (2016).

Woo et al., Chem. Mater. 30, 6684 (2018).

Ko et al., Nature Commun. 10, 5123 (2019).

Ko et al., Nature Catal. Accepted for Publication (2021).

J. Sa et al., ACS Catal. 10, 10920 (2020).

Lim et al., Nature Commun. 11, 412 (2020).

Lim et al., ACS Catal. 11, 12232 (2021).
(Digital Presentation) Peptide Targeting of Photosensitisers for Photodynamic Therapy and Drug Delivery Applications
Authors: Eggleston Ian M. , Yaghini Elnaz , Dondi Ruggero , Tewari Kunal M. , Edler Karen J. , Loizidou Marilena , MacRobert Alexander J. 
Published: July 2022

The conjugation of photosensitisers to proteins or targeting peptides is a well-established approach for enhancing solubility and tissue selectivity for both photodynamic therapy (PDT) of cancer and light-activated drug delivery. A key innovation in the development of such targeted photosensitisers is the application of biorthogonal ligation techniques (e.g. azide-alkyne “click” chemistries) which allow the efficient attachment of various photosensitiser molecules to multifunctional peptides. Some of our work in this area will be described towards the generation of specific targeted conjugates between porphyrin and chlorin photosensitiser derivatives and tumour-homing or cell-penetrating peptide carriers [1, 2]. Conjugation of hydrophobic photosensitiser molecules to cationic cell-penetrating peptides (e.g. HIV Tat 48-57) can provide derivatives with improved water solubility, amphiphilicity, enhanced uptake and predictable sub-cellular localisation. This is very attractive for the light-triggered delivery of macromolecular therapeutics by photochemical internalisation (PCI), which will be illustrated in the application of these compounds for the delivery of the protein toxin, saporin [3].
Peptide targeting strategies are also of interest for PDT with 5-aminolevulinic acid (ALA) [4]. In ALA-PDT, administered ALA is converted within cells via the heme biosynthetic pathway to a classical photosensitiser- protoporphyrin IX. In this context, some recent chemical and biological data will be presented on the use of peptide targeting to enhance the delivery of multiple ALA units to a specific cell type [5].
[1] Dondi, R., Yaghini, E., Tewari, K. M., Wang, L., Giuntini, F., Loizidou, M., MacRobert, A. J. and Eggleston, I. M., Org. Biomol. Chem. 2016, 14, 11488-11501; [2] Yaghini, E., Dondi, R., Tewari, K. M., Loizidou, M., Eggleston, I. M. and MacRobert, A. J., Sci. Rep. 2017, 7, 6059; [3] Yaghini, E, Dondi, R., Edler, K. J., Loizidou, M., MacRobert, A. J. and Eggleston, I. M., Nanoscale 2018, 10, 20366-20376; [4] Tewari, K. M. and Eggleston, I. M., Photochem. Photobiol. Sci. 2018, 17, 1553-1572; [5] Tewari, K. M., Dondi, R., Yaghini, E., Pourzand, C., MacRobert, A. J. and Eggleston, I. M., Bioorg. Chem. 2021, 109, 104667.
(Digital Presentation) Growth of Vdw Heterostructures with Tunable Moiré Patterns
Authors: Fortin-Deschenes Matthieu , Xia Fengnian 
Published: July 2022

Overlaying two two-dimensional (2D) lattices with different periodicities or a relative twist angle gives rise to a larger (quasi-) periodic lattice called a moiré pattern. In van der Waals (vdW) heterostructures, the moiré pattern has recently been shown to display interesting novel physical phenomena. For instance, twisted bilayer graphene near the “magic angle” of 1.1° hosts flat electronic bands and strongly correlated states such as unconventional superconductivity [1, 2]. On the other hand, the moiré pattern has been found to both localize and tune interlayer excitons in transition metal dichalcogenides (TMDCs) heterostructures with small twist angle [3-5]. Such moiré heterostructures are generally produced by mechanical exfoliation and stacking to precisely control the twist angle and moiré periodicity. However, this laborious method leads to interfacial contamination and twist angle inhomogeneities and is inherently not scalable. In principle, direct growth of van der Waals heterostructures can overcome these limitations. However, due to energetic considerations, control over the twist angle, and therefore the moiré lattice, has not yet been achieved. Herein, using TMDCs as a model system, we demonstrate the scalable growth of moiré heterostructures with continuously tunable periodicity. By controlling the substitutional alloying of larger atoms within the same group of the periodic table (S, Se), we precisely engineer the lattice parameters of the 2D layers and the moiré period. The grown moiré heterostructures have lateral size up to 200 μm and are shown to host moiré excitons. These results lay the groundwork for the integration of moiré heterostructures in emerging quantum technologies.
[1] Cao, Y.; Fatemi, V.; Fang, S.; Watanabe, K.; Taniguchi, T.; Kaxiras, E.; Jarillo-Herrero, P. Nature 2018, 556 (7699), 43-50.
[2] Cao, Y., Fatemi, V., Demir, A., Fang, S., Tomarken, S. L., Luo, J. Y., ... & Jarillo-Herrero, P. 2018. Nature, 556 (7699), 80-84.
[3] Yu, H.; Liu, G.-B.; Tang, J.; Xu, X.; Yao, W. (2017). Science Advances 2017. 3 (11), e1701696.
[4] Seyler, K. L.; Rivera, P.; Yu, H.; Wilson, N. P.; Ray, E. L.; Mandrus, D. G.; Yan, J.; Yao, W.; Xu, X. Nature 2019, 567 (7746), 66.
[5] Jin, C.; Regan, E. C.; Yan, A.; Utama, M. I. B.; Wang, D.; Zhao, S.; Qin, Y.; Yang, S.; Zheng, Z.; Shi, S.; et al. Nature 2019, 567 (7746), 76.
(Digital Presentation) Carbon Quantum Dot Assisted Enhancement of S2 Fluorescence of Near-Infrared Dyes through Immobilization-Induced Emission Effect
Authors: Dimitriev Oleg , Piryatinski Yuri , Sharanov Illya , Slominskii Yuri 
Published: July 2022

Aggregation-induced emission of organic dyes is a phenomenon in which organic luminophores show higher photoluminescence (PL) efficiency in the aggregated state than in a free molecule, due to the freezing rotational degrees of freedom of the luminophore which otherwise quench the PL emission. In many cases, however, coupling of molecules leads to quenching of their emission due to the concentration quenching or self-quenching (exciton-exciton annihilation) effect. Therefore, in order to realize an enhanced PL emission as a result of molecule-molecule interaction a fine balance should be achieved between freezing rotational degrees of freedom of the molecule and escaping self-quenching effect. This could be realized via immobilization of the luminophore onto the inert surface.
Here, we demonstrate an enhancement of specific S2 emission of the near-infrared (NIR) dyes of tricarbocyanine family due to their immobilization on the surface of carbon nanoparticles that induce freezing a specific planar conformation of the molecule imposed by the carbon plane of the particle it interact with. Carbon quantum dots serve as inert particles that render an opposite influence on the S1 and S2 emission of the tricarbocyanine dyes. We demonstrate a dual emission of the NIR tricarbocyanine dyes with a bright green S2 fluorescence, which is relatively weak for the free dye molecule but whose quantum yield increases by 2-4 times, together with a strong enhancement of the spontaneous rate of S2 fluorescence, whereas the quantum yield of S1 emission in the NIR decreases by 2-7 times, respectively, as a result of immobilization of the dye molecule via the interaction with carbon quantum dots. The above changes are dependent on the terminal and meso-groups of the dye and the solvent used. The dye immobilization due to interaction with carbon quantum dots causes freezing rotational degrees of freedom of the molecule as indicated by suppression of the dye hot band absorption-assisted anti-Stokes S1 emission.
The observed “lighting up” of an anti-Kasha emission, i.e., the emission from Sn (n>1) excited levels, of the NIR chromophores which possess intensive S1 absorption and emission in the NIR region, but which are spectrally silent in the visible, can lead to their potential applications in the fields such as energy conversion, bio-imaging and bio-sensing, sensitization of solar cells, etc.
Ionic Liquid/Non-Ionic Surfactant Mixtures As Versatile, Non-Volatile Electrolytes: Double-Layer Capacitance and Conductivity
Authors: Lashkari Sima , Lashkari Sima A. , Pal Rajinder 
Published: July 2022

Self-assembly of ionic liquids (ILs) on 2D materials such as graphene oxide and MXenes facilitated by non-ionic surfactants is a promising approach being increasingly used for the fabrication of high surface area electrodes resulting in high performance supercapacitors. However, the impact that non-ionic surfactants have on double-layer formation and ionic conductivity has yet to be explored. These surfactants are not ionically conductive, have low dielectric constants and high viscosity which are expected to impact the final performance of the electrode.
In this study we analyze the effect of adding two commonly used non-ionic surfactants, P123 and Triton X-100 (TX-100) to 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMImTFSI) on the double-layer capacitance formed at a glassy carbon electrode by means of electrochemical impedance spectroscopy. The results, surprisingly suggest an improvement of 75% and 116% in the double layer capacitance measured at the open circuit voltage for 40% of P123 and TX-100, respectively. We also interpret the changes in the DC potential dependence of the capacitance via the most up-to-date understanding of double-layer charging mechanisms with ionic liquids. Similar to previous literature on solvent-based diluents such as polycarbonate and acetonitrile, which cause a similar effect, the improved capacitance is attributed to the reduced Debye length resulting from an increased effective ionic charge accrued by the IL when surrounded by the low-dielectric constant surfactant.
Both electrolyte series show the same reduction in ionic conductivity (from 8.5 mS/cm to 1 mS/cm) with respect to concentration regardless of the higher viscosity measured for the P123 electrolyte series. Pulsed field gradient nuclear magnetic resonance, is used to determine the diffusion coefficient for the IL as a function of surfactant concentration and allow us to calculate the effective Stokes radius which is found to shrink significantly as a function of surfactant concentration. Similar to the improved capacitance, this is caused by a reduction in ion-ion interactions and an increase in the average effective charge on each ion. These effects make the electrolyte less sensitive than expected to the increased viscosity caused by addition of the more viscous surfactant phase.
The ability to improve the capacitance with non-volatile, low dielectric constant additives, without significantly sacrificing ionic conductivity, opens up an improved avenue for completely non-volatile, non-flammable electrolyte design.
(Digital Presentation) Offshore Gas Turbines
Authors: Abubakar Muhammad , Omavuezi Omefe , Sumner Joy 
Published: July 2022

Offshore gas turbines are the main power drivers for offshore production facilities; they are used for gas lifting, pumping, power generation and compression due to their high power to weight ratio and size. It is therefore imperative to minimize their downtime to prevent production losses. The need to examine the how deposits formed on the blade surface limits the life and performance of the engine cannot be overemphasized.
In this study the Rolls Royce RB211, an aero derivative engine commonly used offshore was selected and its performance data obtained from PYTHIA engine simulation and diagnostic software. These values were used to calculate the rate of mass deposition of potassium sulphate (K2SO4), a potential corrosive salt.
In order to determine rate of mass deposition, contaminant levels for a clean gas and good filter were obtained from General Electric’s fuel specification while a higher contaminant level was assumed.
It was found that at high temperature corrosive salt tend to deposits on the blade surface when concentration of contaminants was calculated for both low and high impurity levels. It was also observed that the rate of mass deposition was high at the first stage of the turbine section where high gas temperature and pressure is usually experienced and drops as hot gas travel along the turbine and leaves as exhaust gas at very low temperature and pressure.
In order to minimize the risk of damage to turbine hot section components like nozzle guide vanes and blades, fuel purity specifications and an appropriate inlet air filtration system must be used. This keeps contaminants in the combusted gas below allowable contaminant levels as recommended by original equipment manufacturers.
Corrosion Mechanisms in Additively Manufactured 316L Stainless Steels
Authors: Voisin Thomas , Zhang Yuliang , Sen-Britain Shohini , Qi Zhen , Kang Shinyoung , Keilbart Nathan Daniel , Cho Seongkoo , Zhu Yakun , Shi Rongpei , Matthews Manyalibo , Wang Y. Morris , Qiu Roger , Wood Brandon C. 
Published: July 2022

Additively manufactured 316L stainless steels (316L SS) using laser powder bed fusion technique (L-PBF) exhibit an excellent combination of high strength and ductility compared to the conventional counterpart. The outstanding material mechanical properties originate from the sub-grain cellular structures developed during the rapid solidification inherent to L-PBF. These structures consist of elongated cells decorated by high density of dislocations, trapped solute, and fine precipitates at their boundaries. The impact of such cellular structures on corrosion resistances, however, remains incompletely understood. In addition, the L-PBF process leads to high surface roughness and usually around 0.1 to 0.5% of porosity. However, the pitting potential of the L-PBF 316L SS can be an order of magnitude higher than the conventional, well annealed counterpart.
In this talk, we will first present a detailed multi-scale characterization of the microstructural features unique to L-PBF 316L SS. In a second part, we will present our experimental-simulation integration approach where we combine surface chemistry mapping and electron and atomic force microscopy with multi-scale simulations to understand the effect of local microstructure variations on pitting and metal dissolution rates in NaCl and HCl environments.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Authors acknowledge the support of the Laboratory Directed Research and Development (LDRD) program (20-SI-004) at LLNL.
Highly Textured Zinc Thin Films through Novel Pulsed Electrodeposition Techniques and Their Applications
Authors: Martin Jason , Mack Ella , King Seth , Sen Sujat 
Published: July 2022

The electrodeposition of zinc thin films has been widely investigated with extensive applications in corrosion, battery electrodes, photo- and electro-catalysis. Traditionally, the direct current (DC) method of electroplating has been explored in terms of varying current density to obtain changes in morphology, grain size, preferred crystalline orientation, which in turn have significant consequences for properties such as catalysis and corrosion resistance. We have recently demonstrated [1] a novel, additive-free pulsed plating method to control the specific crystalline growth orientations and average grain size of zinc electrodeposited on steel substrates.
Specifically, we have observed a transition of the preferential (002) facets at low peak current density (or low duty cycle) to (101) preferring facets at higher peak current density (or high duty cycle) as determined by the analysis of texture coefficients. Further analysis using scanning electron microscopy reveals a transition from the conventional hexagonal-shaped particles of zinc to needle-shaped structures, accompanied by a change in average crystallite size from 33 to 19 nanometers, determined from X-ray diffraction studies. The variation in morphology is also correlated to crystallographic textures through the analysis of texture coefficients and an understanding of crystallization mechanisms occurring during deposition.
Herein, we report on an application of these highly textured zinc-coated steel substrates towards corrosion resistance, through accelerated electrochemical testing. Using industry-standard ASTM methods such as Linear Polarization Resistance (LPR), Linear sweep voltammetry (LSV) and electro-impedance spectroscopy (EIS) measurements, we report on preliminary findings of corrosion potential, current and corrosion rates expressed in mm per year as a function of crystalline texture of the zinc thin films.
References
[1] L. Fuller, J. Martin, S. King and S. Sen, “Control of Texture and Morphology of Zinc Films through Pulsed Methods from Additive-Free Electrolytes”, 6, 22, pp.5426 - 5434, ChemistrySelect, 2021
Effects of Interlayer Properties on Electrochemical Ion Intercalation and Electrosorption in Layered and 2D Electrode Materials
Authors: Fleischmann Simon 
Published: July 2022

The kinetics of electrochemical intercalation and electrosorption processes are often limited by the solid-state diffusion of ions inside the lattice of the host material. While some of these limitations can be mitigated by nanostructuring of the electrode material, there is a large interest in the electrochemical energy storage community to find materials with structural motifs that allow for intrinsically fast ion diffusion, even in bulk-sized particles.
In this presentation, it will be highlighted how interlayer properties, such as interlayer distance and interlayer chemistry, affect electrochemical ion intercalation and electrosorption processes in layered host materials. Using the examples of hydrogen titanates1 and Ti3C2Tx MXenes2, it is demonstrated that the presence of structural interlayer atoms or molecules can increase the accessibility of ions to the interlayer space. In the model layered host material TiS2, it is shown that increased interlayer spacing and reduced deformation during ion intercalation can lead to a change from diffusion-limited to non-diffusion limited (or pseudocapacitive) charge storage behavior,3 providing some of the most compelling experimental evidence of the intimate relationship between deformation, interlayer distance, and intercalation kinetics in layered host materials.
This contribution will emphasize the importance of interlayer properties of layered and 2D materials for electrochemical ion intercalation and electrosorption processes and provide perspectives and design strategies for next generation ion insertion hosts with fast kinetics for high power energy storage.

Fleischmann, S. et al. Interlayer separation in hydrogen titanates enables electrochemical proton intercalation. J. Mater. Chem. A
8, 412–421 (2020).

Liang, K. et al. Engineering the Interlayer Spacing by Pre-Intercalation for High Performance Supercapacitor MXene Electrodes in Room Temperature Ionic Liquid. Adv. Funct. Mater.
31, 2104007 (2021).

Fleischmann, S., Shao, H., Taberna, P.-L., Rozier, P. & Simon, P. Electrochemically Induced Deformation Determines the Rate of Lithium Intercalation in Bulk TiS2. ACS Energy Lett.
6, 4173–4178 (2021).