bluuebunny/crossref_metadata_2025_split huggingface dataset:
N-Confused Metallocorroles: Synthesis, Redox Properties, and Catalytic Activities
Authors: Ishida Masatoshi , Furuta Hiroyuki 
Published: July 2021

Corrole is known as a contracted tetrapyrrolic macrocycle bearing an α,α'-linked bipyrrole moiety. Using a unique trianionic N4 donor environment at the inner core, various high-valent metal species have been examined for potential catalytic applications. To seek new reactivity of metallocorroles, we have previously designed and synthesized a specific carbacorrole ligand, namely N-confused/N-linked corrole analogs.[1] The former analog contains an inverted pyrrole moiety connected at the α and β’-linking positions, and the latter has a peculiar linkage between the pyrrole α-position and the pyrrolic nitrogen site. The distinct [NNNC] coordination environment of these carbacorroles stabilizes unique organometallic species such as a copper(III).[2]
In this work, we synthesized novel cobalt complexes with a benzo-fused corrole analog (i.e., benzonorrole). The electronic structure of the resulting complex is highly dependent on the number of axial pyridine ligands. The bis-pyridine adduct complex can be regarded as a diamagnetic Co(III) species. Removal of an axial pyridine ring from the corresponding complex yielded the oxygenated product at the inner carbon site immediately. Unlike the bis-pyridine adduct, the mono-pyridine cobalt complex is a singlet Co(II) ligand radical at the ground state as inferred from various spectroscopic means and DFT calculations. Due to the intrinsic redox-noninnnocent character, the cobalt(II) radical complex exhibits facile reduction nature. On this basis, we finally applied for catalytic hydrogen evolution reaction with these cobalt 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.
Vitamin B12 – Bioinspiration for Catalysis
Authors: Gryko Dorota 
Published: July 2021

Nature constructs and decomposes complex molecules with the help of enzymes and light as the ultimate energy source. However, despite enzyme’s fundamental benefits, their industrial application can be limited by their availability, instability towards certain reaction conditions, cost, scale, lack of suitable enzyme etc. A complementary approach to sustainable methodologies relies on the formation or cleavage of chemical bonds using bioinspired methods (methods imitating the efficient and elegant designs of biology) and recruiting light, the most abundant free energy source.
Vitamin B12 - a cofactor of many enzymes seems inspirational.[1,2] This type of catalysis has been successfully translated into the laboratory and used in a small collection of reactions.[2, 3] 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.
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. Under light irradiation vitamin B12 derivative unusually catalyzes a new olefinic sp2 C-H alkylation reaction, with diazo reagents as a carbene source, instead of the expected cyclopropanation, acylation of activated olefins. Light-induced vitamin B12-catalyzed methods are also suitable for C-O bond cleavage. 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.
[1] Banerjee, R. Chemistry and Biochemistry of B12, John Wiley & Sons, Inc, 1999; [2] K. ó Proinsias, M. Giedyk, D. Gryko, Chem. Soc. Rev.
2013, 42, 6605-6619. [3] Giedyk, M.; Fedosov, S.; Gryko, D. Chem.
Commun.
2014, 50, 4674-4676.

Figure 1
Molecular Co and Fe Catalysts for the Electrochemical and Photoelectrochemical CO2 Reduction with 2, 4, 6 and 8 Electrons
Authors: Robert Marc 
Published: July 2021

Reduction of carbon dioxide has as main objective the production of useful organic compounds and fuels - renewable fuels - in which solar energy would be stored. Molecular catalysts can be employed to reach this goal. One route consists in first converting sunlight energy into electricity that could be further used to reduce CO2 electrochemically. Another approach is to directly use the visible photons and photo-stimulate the electrochemical reduction of the gas in the presence of an appropriate light absorbing material. Molecular catalysts may provide excellent selectivity. Hybrid systems in which a robust molecular catalyst is associated to a conductive or a semi-conductive support may combine the advantages of both homogeneous and heterogeneous catalysis.
Using Co and Fe bio-inspired complexes (porphyrins, phthalocyanines and quaterpyridines), our recent results for CO, HCOOH, CH3OH and CH4 production at molecular cathodes [1-5] and photocathodes [6-8] will be discussed. We will illustrate the synergy between electrochemical and photochemical approaches and the rich potential of molecular catalysts to generate fuels from CO2 used as a renewable feedstock.
References: [1] Wang, L. Chen, T-C. Lau, M. Robert, Angew. Chem. Int. Ed. 2018, 57, 7769-7773. [2] Ren, D. Joulie, D. Salvatore, K. Torbensen, M. Wang, M. Robert, C. Berlinguette, Science 2019, 365, 367-369. [3] Wang,K. Torbensen, D. Salvatore, S. Ren, D. Joulie, F. Dumoulin, D. Mendoza, B. Lassalle-Kaiser, U. Işci, C. Berlinguette, M. Robert, Nat. Commun. 2019, 10:3602. [4] Boutin, M. Wang, J. C. Lin, M. Mesnage, D. Mendoza, B. Lassalle-Kaiser, C. Hahn, T. F. Jaramillo, M. Robert, Angew. Chem. Int. Ed. 2019, 58, 16172-16176. [5] Azcarte, C. Costentin, M. Robert, J.-M. Savéant, J. Am. Chem. Soc. 2016, 138, 16639-16644. [6] Guo, C. Cometto, G. Chen, L. Chen, B. Ma, H. Fan, T. Groizard, W-L. Man,S-M. Yiu, K-C. Lau, T-C. Lau, M. Robert, Nat. Catal. 2019, 2, 801-808. [7] Ma, G. Chen, C. Fave, L. Chen, R. Kuriki, K. Maeda, O. Ishitani, T-C. Lau, J. Bonin, M. Robert, J. Am. Chem. Soc. 2020, 142, 13, 6188-6195. [8] B. Pati, E. Boutin, R. Wang, S. Diring, S. Jobic, N. Barreau, F. Odobel, M. Robert, Nat. Commun. 2020, 11:3499.
Highly Efficient (>15%) Organic Solar Cells Based on Porphyrins
Authors: Cuesta Virginia , de la Cruz Pilar , Sharma Ganesh D , Langa Fernando 
Published: July 2021

The optical and electrochemical properties of porphyrins can be tailored by changing the central metal and functionalization of the periphery, being excellent candidates as donors for Organic Solar Cells (OSCs). In the early years, the PCE values of OSCs based on porphyrins were very low, but by structural modifications, we achieve efficiencies in the range of 15%. In this presentation, I´ll show our recent work in design, synthesis and application of A−π−D−π−A and D−π−A−π−D porphyrin-based small molecules for highly efficient OSCs.
References

V. Cuesta, M. Vartanian, P. d. l. Cruz, R. Singhal, G. D. Sharma and F. Langa, J. Mater. Chem. A, 2017,
5, 1057-1065.

S. Arrechea, A. Aljarilla, P. de la Cruz, M. K. Singh, G. D. Sharma, F. Langa. J. Mater. Chem. C,
2017, 5, 4742.

M. Vartanian, R. Singhal, P. de la Cruz, S. Biswas, G. D. Sharma and F. Langa, ACS Appl. Energy Mater.
2018, 1, 1304.

M. Vartanian, P. de la Cruz, F. Langa, S. Biswas, G. D. Sharma. Nanoscale,
2018, 10, 12100-12018.

M. Vartanian, R. Singhal, P. de la Cruz, G. D. Sharma, F. Langa, Chem. Commun, 2018, 54,14144-14147.

V. Cuesta, R. Singhal, P. de la Cruz, G. D. Sharma, F. Langa, ACS Mater. Interfaces, 2019, 11, 7216-7225.

Cuesta, R. Singhal, P. de la Cruz, G. D. Sharma, F.Langa ChemSusChem
2020 DOI: 10.1002/cssc.202002664.

Figure 1
Electron-Triggered Metamorphism in Porphyrin-Based Self-Assembled Supramolecular Polymers
Authors: Bucher Christophe , Chowdhury Shagor , Kahlfuss Christophe , Nassar Youssef , Al Shehimy Shaymaa , Dumont Elise , Demets Grégoire J. F. , saint-Aman Eric , Frath Denis , Chevallier Floris 
Published: July 2021

Stimuli-responsive self-assembled molecular materials are currently subject to intense research activity. This growing interest stems largely from the myriad of exciting applications envisioned for dynamic supramolecular assemblies, also known as dynamers, in materials science, sensing, catalysis and electronics. Enormous technologic interests are for instance at stake in being able to devise molecular objects that could respond to external stimuli by changes in structure and function. These particular properties can lead to applications in various domains as (i) in molecular electronics, (ii) in analytic science, with switchable hosts allowing the controlled binding/release of pollutants or drugs, (iii) in materials science with the development of adaptive supramolecular polymers. Our group has been focusing over the past few years on the development of tailor-made redox-controllable molecular and supramolecular systems involving electrogenerated pi-radicals as key responsive and/or assembling elements [1-3]. In this lecture, we will focus on the physico-chemical properties of a series of porphyrin-based molecular tectons whose self-assembly can be controlled with optical or electrical stimulus. The dynamic properties of these stimuli-responsive molecular architectures and molecular materials will mainly be discussed on the basis of electrochemical, spectroelectrochemical and ESR experiments supported by quantum chemical calculations [4-7].

References

[1] C. Kahlfuss, E. Saint-Aman, C. Bucher (2016). Redox-controlled intramolecular motions triggered by π-dimerization and πmerization processes In T. Nishinaga (Ed.), Organic Redox Systems: Synthesis, Properties, and Applications (pp. 39). New-York: John Wiley and sons.
[2] H. D. Correia, S. Chowdhury, A. P. Ramos, L. Guy, G. J.-F. Demets, C. Bucher, Polymer International 68, 572 (2019).
[3] G. Brunet, E. A. Suturina, G. P. C. George, J. S. Ovens, C. Bucher, M. Murugesu, Chemistry - A European Journal, DOI: 10.1002/chem.202003073 (2020).
[4] S. Chowdhury, Y. Nassar, L. Guy, D. Frath, F. Chevallier, E. Dumont, A. P. Ramos, G. J.-F. Demets, C. Bucher, Electrochimica Acta 316, 79 (2019).
[5] C. Kahlfuss, S. Denis-Quanquin, N. Calin, E. Dumont, M. Garavelli, G. Royal, S. Cobo, E. Saint-Aman, C. Bucher, Journal of the American Chemical Society 138, 15234−15242 (2016).
[6] C. Kahlfuss, T. Gibaud, S. Denis-Quanquin, S. Chowdhury, G. Royal, F. Chevallier, E. Saint-Aman, C. Bucher, Chemistry - A European Journal 24, 13009 (2018).
[7] C. Kahlfuss, R. Gruber, E. Dumont, G. Royal, F. Chevallier, E. Saint-Aman, C. Bucher, Chemistry - A European Journal 25, 1573 (2019).
NMR Investigation of Transport in Polybenzimidazole/Polyphosphoric Acid Membranes Prepared Via Novel Synthesis Route
Authors: Garaga Mounesha G , Murdock Laura , Pranto Tawhid , Suarez Sophia , Greenbaum Steven G. , Benicewicz Brian 
Published: July 2021

Previous work by the some of us has demonstrated enhanced electrochemical performance of polybenzimidazole (PBI) membranes with high phosphoric acid content prepared by the so-called PPA process.1 Methods of PBI synthesis that involve casting from an organic solvent cannot incorporate the more rigid PBIs characteristic of the PPA process due to their limited solubility. Recently, a carefully controlled drying method has been discovered in which a gel PBI membrane, made in the PPA process, is transformed into a dense PBI film. This method provides a synthetic route to PBI films without the use of any organic solvents. The dense PBI films with repeat unit para-PBI (Fig.1), were originally developed for flow battery applications. However they also can be re-doped in phosphoric acid to be used as a membrane in high-temperature fuel cells.
The re-doped PBI films have displayed unprecedented ionic conductivity at elevated temperatures, similar to the starting PBI gel membranes prepared by the PPA process1, while also exhibiting enhanced mechanical properties. Temperature-dependent conductivity data for two of these films are displayed below. Sample A is the dried, densified, and re-acidified version of sample B, with a much lower acid content, ~18 mol PA/PBI repeat unit compared to 30 mol PA/PBI RU, respectively, but exhibits comparable conductivity (Fig. 2). Thus, in high-temperature fuel cell operation the electrochemical performance is similar, but performance degradation due to mechanical creep is reduced, leading to greater durability of the Version A PBI.
In attempting to understand the enhanced proton conductivity of the modified PBI membrane despite its lower acid content, we performed both 1H and 31P nuclear magnetic resonance (NMR) measurements. Proton self-diffusion coefficients for four membranes two (A,C) prepared by the modified process and two (B,D) by the original PPA process, were measured by pulsed gradient NMR and plotted in Fig. 3.
The results show significantly enhanced proton diffusivity, both in magnitude and in lower activation energy for sample A, which is consistent with its high conductivity despite lower acid content compared to the original PPA-processed membranes (B, D). We have also performed solid state 1D 31P and 2D 31P{1H} HETCOR NMR measurements, which yield additional information on structural differences between the membranes and how these differences may affect transport properties.

Multinuclear NMR Study of the Effect of Acid Concentration on Ion Transport in Phosphoric Acid Doped Polybenzimidazole Membranes, N. Suarez, N.K.A.C. Kodiweera, P. Stallworth, S.G. Greenbaun, S. Yu, and B. Benicewicz, Journal of Physical Chemistry B, 116, 12545-51(2012).

Figure 1
The Influence of Inclusions on the Electrochemical Behavior of FeCrNiCoMn and Fecrnico Alloys
Authors: Hsu Kuo Min , Chen Sz-Han , Lin Chao-Sung 
Published: July 2021

FeCrNiCoMn and FeCrNiCo, which are familiar types of high entropy alloys, have drawn a lot of attention due to their promising mechanical properties at cryogenic temperature. In this research, the microstructure and corrosion behavior of the passive films on the homogenized-hot rolled FeCrNiCoMn and FeCrNiCo alloys were studied in 0.5 M H2SO4. (Mn,Cr)(O,S), (Cr,Mn)O, and MnS were the three main inclusions present in FeCrNiCoMn while CrO was the primary inclusion in FeCrNiCo, as identified by energy dispersive x-ray spectroscopy shown in Figure (a) as representative. After pickling with HF-HNO3 mixed solution according to the standard of ASTM A380M-17, the inclusions were barely found in both alloys.
The corrosion resistance of the passive film was investigated using electrochemical impedance spectroscopy after pickling, as displayed in Figure (b). It was found that the resistance of FeCrNiCoMn improved while FeCrNiCo deteriorated following the pickling. Therefore, inclusions containing Mn were deduced to be detrimental to the corrosion resistance for FeCrNiCo-type high entropy alloys.

Figure 1
Effect of Alloy Microstructure on the Corrosion Behavior of Binary Mg-Y Alloys
Authors: Su Yu-You , Chu Peng-Wei 
Published: July 2021

In recent years, magnesium alloys continue to receive attention due to their low density and high specific strength compared to other metallic materials. However, the main disadvantage of magnesium alloys originates from the low standard reduction potential of magnesium (-2.37 VSHE), resulting in high reactivity in water-containing environments and susceptibility to corrosion reaction. This kind of corrosion phenomenon exists in most magnesium alloys, thus limiting their practical applications.
At present, many studies showed that adding yttrium to magnesium can simultaneously improve its creep and corrosion resistance. Also, the standard reduction potential of yttrium is similar to that of magnesium, which implies that the galvanic corrosion effect due to the second phases or precipitates would be less pronounced with the addition of yttrium. Therefore, in this study, we investigated the influence of alloy microstructure on the corrosion behavior of two binary magnesium-yttrium (Mg-Y) alloys with different yttrium content.
To understand the dominant features during corrosion tests, this study used an in situ optical microscope (OM)/three-electrode setup to monitor the evolution in corrosion potential and surface corrosion morphology with immersion times of the Mg-Y alloys. With this setup, serious localized corrosion was observed on the Mg-1wt%Y sample. In contrast, localized corrosion on the Mg-7wt%Y sample is mitigated, and the corrosion rate is maintained at a similar level over time. Even though the addition of more Y results in more second phases or precipitates, which could cause some galvanic effect, the corrosion propagation is delayed by the second phase distribution. Through further observation in scanning electron microscope (SEM) and focused ion beam (FIB) systems, the corrosion mechanism of binary Mg-Y alloys will be discussed based on the distribution of local cathodes and anodes on the alloy surface.

Figure 1
A Method of Chemical-Mechanical Polishing of a Thick Silver Layer on Patterned Silicon Wafer
Authors: Danilkin Evgeny V , Gaydeday Valentina A , Valdez Jose , Piguzov Mikhail Y , Krupnik Vladimir M , Ivanov Igor , Niu Licheng , Ermakov Sergey S 
Published: July 2021

Microfluidics-based biochips for biochemical analysis are receiving much attention nowadays. These composite microsystems, also known as lab-on-a-chip or bio-MEMS, offer a number of advantages over conventional laboratory procedures. They automate highly repetitive laboratory tasks by replacing cumbersome equipment with miniaturized and integrated systems, and they enable the handling of small amounts, e.g., micro- and nano-liters, of fluids. Thus they are able to provide ultra-sensitive detection at significantly lower costs per assay than traditional methods, and in a significantly smaller amount of laboratory space. Advances in microfluidics technology offer exciting possibilities in the realm of enzymatic analysis (e.g., glucose and lactate assays), DNA analysis (e.g., PCR and nucleic acid sequence analysis), proteomic analysis involving proteins and peptides, immuno-assays, and toxicity monitoring.
Biochips can be used to detect molecules and/or sequence nucleic acid molecules with aid of an array of electrochemical detector cells containing one or more electrodes per cell where each cell being electrically isolated at a wafer level. For many applications it is beneficial to form a non-planar working electrode using a metal which will corrode during CMP steps.
We’ve developed a novel Ag and Cu integration process which a) solves problems of metal corrosion over 3D topography during CMP step and b) prevents metal surface contamination with CMP residual slurry and polishing byproducts not usually removable by brush or megasonic cleaning.
Electrochemical studies show corrosion behavior of thick Ag layers in different CMP slurries used in this process. SEM images of cross-sectioned metal lined electrochemical cells (vias) clearly demonstrate advantages of new process (right) without traces of corrosion vs conventional CMP process (left).
This process can be used also for polishing of other metals and dielectrics over topography where aggressive cleaning post-CMP steps are not desirable.

Figure 1
Challenges and Solutions for Post-CMP Cleaning of Ceria Particles for Advanced Technology Nodes
Authors: Seo JIhoon , Gowda Akshay , Babu S.V. 
Published: July 2021

It has been very difficult to remove smaller ceria particles from oxide surfaces after polishing. As the particle size decreases from 90 to 10 nm, cleaning efficiency of SC1 solution decreases from ~94 % to ~19 %, presumably because smaller ceria particles with a higher surface concentration of Ce3+ are more strongly coupled with silicon dioxide surfaces via strong Ce-O-Si bonding. (1) As was reported earlier, where the cleaning of oxide surfaces of ceria particles from slurries containing no additives, we reported that equimolar solutions containing H2O2 and NH4OH (4.2 mol l−1 each of H2O2 and NH4OH), aided by ultrasonic cleaning, and at high pH could almost completely remove even 10 nm sized ceria particles from silicon dioxide film surfaces. (1)
However, a cleaning solution containing H2O2 and NH4OH at equal molar (4.2 mol l−1) was not effective in cleaning oxide and nitride surfaces contaminated with ceria particles in the presence of additives such as proline and citric acid. (2) Recently, we reported a cleaning solution comprising 1 wt% ascorbic acid, 1 wt% ammonium carbonate and 50 ppm Triton X-100 at pH 12, aided by ultransonic energy, to clean ~30 nm ceria particles from both oxide and nitride films with ~ 99% cleaning efficiencies. The binding between the additive-covered ceria particle particles and the oxide/nitride surfaces could be broken by the nucleophilic attack of hydroxyl ions. Ascorbic acid and ammonium carbonate prevent ceria particle redeposition by adsorbing on the surface of the removed particles and blocking the active Ce3+ species. Triton X-100 reduces adhesion between the particle and the film surfaces during cleaning.
(1) Seo, J., Gowda, A., & Babu, S. V. (2018). Almost complete removal of ceria particles down to 10 nm size from silicon dioxide surfaces. ECS Journal of Solid State Science and Technology, 7(5), P243.
(2) Gowda, A., Seo, J., Ranaweera, C. K., & Babu, S. V. (2020). Cleaning Solutions for Removal of∼ 30 nm Ceria Particles from Proline and Citric Acid Containing Slurries Deposited on Silicon Dioxide and Silicon Nitride Surfaces. ECS Journal of Solid State Science and Technology, 9(4), 044013.