Article
Chemistry, Inorganic & Nuclear
Markus Stroebele, Oliver Oeckler, Michael Thelen, Reinhold F. Fink, Arun Krishnamurthy, Scott Kroeker, Hans-Juergen Meyer
Summary: The crystal structures of niobium pnictide halides Nb4PnX11 (Pn = N, P; X = Cl, Br, I) have been reported, and their electronic and magnetic properties have been analyzed. The individual pnictide-capped butterfly cluster cores [Nb4P] in the structure are interconnected into two-dimensional layers.
INORGANIC CHEMISTRY
(2022)
Article
Polymer Science
Alexander Plucinski, Marko Pavlovic, Mairi Clarke, David Bhella, Bernhard V. K. J. Schmidt
Summary: The study investigated the aggregation behavior of high molar mass block copolymer in an organic solvent, revealing unprecedented behavior under specific conditions. Potential future applications in photonics and templating of inorganic structures were envisioned for this new thermo-responsive block copolymer.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Lilia S. S. Xie, Oscar Gonzalez, Kejun Li, Matteo Michiardi, Sergey Gorovikov, Sae Hee Ryu, Shannon S. Fender, Marta Zonno, Na Hyun Jo, Sergey Zhdanovich, Chris Jozwiak, Aaron Bostwick, Samra Husremovic, Matthew P. Erodici, Cameron Mollazadeh, Andrea Damascelli, Eli Rotenberg, Yuan Ping, D. Kwabena Bediako
Summary: Magnetic materials with noncollinear spin textures have potential for spintronic applications. Control over the length and energy scales of these spin textures is crucial for practical devices. The chiral helimagnets Cr1/3NbS2 and Cr1/3TaS2 exhibit similar magnetic phase diagrams but with different real-space periodicities, making them ideal for studying the underlying mechanisms of exotic spin textures. We conducted a comprehensive set of electronic structure studies on both Cr1/3NbS2 and Cr1/3TaS2 using angle-resolved photoemission spectroscopy and density functional theory. Our results reveal that the bands in Cr1/3TaS2 are more dispersive compared to Cr1/3NbS2, leading to different Fermi wavevectors. Despite these differences, the qualitative magnetic phase diagrams remain identical, indicating that hybridization between the intercalant and host lattice mediates the magnetic exchange interactions in both materials. We also found that ferromagnetic coupling is stronger in Cr1/3TaS2, but the heavier host lattice results in larger spin-orbit coupling and a stronger Dzyaloshinskii-Moriya interaction, leading to shorter spin textures.
CHEMISTRY OF MATERIALS
(2023)
Article
Materials Science, Ceramics
Arseniy Bokov, Anna Shelyug, Alexey Kurlov
Summary: The study demonstrates successful sintering of TaC and NbC ceramics with high densities, showcasing hardness of 20-25 GPa through reduction in carbon stoichiometry and submicron grain sizes. XRD, SEM, and TGA-DSC were employed to investigate the phenomena during processing, revealing the presence of oxygen impurities in carbide particles and decarburization and oxide segregation during sintering. The effects of decarburization and oxide segregation can be counteracted by carbon excess, but controlling the densification curve can be challenging in such cases.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Engineering, Chemical
Swastika Choudhury, Samit Kumar Ray
Summary: The organophilic character of PVC membrane was improved through graft copolymerization and further filling with organo clay, for sorption and pervaporation of tetrahydrofuran. Experimental data showed different flux/THF selectivity for PVC membranes grafted with different materials when treating THF.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
James Braun, Cedric Sauder, Christine Gueneau, Fiqiri Hodaj, Fanny Balbaud-Celerier
Summary: This study evaluates the chemical compatibility of niobium and tantalum with SiC at high temperatures using diffusion couple experiments. The results show that niobium and tantalum are chemically compatible with SiC, making them suitable liner materials for hybrid CMC/metal cladding materials.
Article
Chemistry, Physical
Ivana Zrinski, Alexey Minenkov, Cezarina Cela Mardare, Achim Walter Hassel, Andrei Ionut Mardare
Summary: Composite memristors based on anodic oxidation of Hf superimposed on Ta thin films were studied, showing promising memristive properties in the Hf/Ta thickness ratio between 4 and 5. The study on the structure and working principle of the composite oxide memristors provides insights for their application and optimization.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
Kazuhisa Sato, Toshiya Matsushita
Summary: Structural defects in (Ta1-xTix)Se-2 compounds with anisotropic electrical conductivity were studied by observing cross-sectional images. Intercalants were found in the widest space between Se atoms, independent of Ti content or thermal history. The presence of Ti stabilized the 1T structure, reducing stacking faults. Chemical composition was found to dominate the structural defects in these compounds.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Tatsuto Hatanaka, Takuya Nomoto, Ryotaro Arita
Summary: Transition metal dichalcogenides (TMDs) exhibit various magnetic structures through intercalation of other transition metal atoms. To understand the chemical trend of the magnetic properties, we conducted a first-principles study on 48 compounds with different hosts, guests, and composition ratios. By applying spin density functional theory and the local force method, we derived classical spin models that are consistent with experimental results and explained the chemical trend in terms of 3d orbital occupancy. These findings can guide the prediction of magnetic structures in yet-to-be-synthesized compounds.
Article
Materials Science, Multidisciplinary
A. E. Hall, D. D. Khalyavin, P. Manuel, D. A. Mayoh, F. Orlandi, O. A. Petrenko, M. R. Lees, G. Balakrishnan
Summary: Temperature evolution of the magnetic structure of V1/3NbS2 was investigated using neutron diffraction techniques, revealing two propagation vectors and specific magnetic couplings. Magnetic susceptibility and heat capacity measurements provided insights into the antiferromagnetic transition temperature and magnetic moment saturation behavior of V1/3NbS2 under different magnetic fields.
Article
Polymer Science
Alexander Kleine, Ulrich S. Schubert, Michael Jaeger
Summary: This study investigates the preparation of poly(N-alkyl-3,6-carbazole)s with defined alpha-/omega-end groups using a commercial Buchwald-type pre-catalyst. It is found that an excess of monofunctional aryl halide favors the Suzuki-Miyaura catalyst-transfer polymerization (SCTP) mechanism, resulting in heterotelechelic polymers with defined molar masses, narrow dispersities, and high chemical yields.
Article
Geochemistry & Geophysics
Mingdi Gao, Xiaolin Xiong, Fangfang Huang, Jintuan Wang, Chunxia Wei
Summary: The experiment results show that the partition coefficients (D-Nb and D-Ta) of Nb and Ta in biotite increase with the decrease of non-bridging oxygens in the melt, as well as the decrease of water content and the increase of biotite magnesium content. By applying these experimental results to the process of granite differentiation, we found that crystallization of biotite is the main cause of the low Nb and Ta enrichments in most rare metal granites.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Polymer Science
Xianqiang Zeng, Liguo Wang, Yan Cao, Chen Liu, Ziqiang Han, Peng He, Huiquan Li
Summary: In this study, a series of poly(1,2-butylene oxide-stat-tetrahydrofuran)s (PBO-stat-PTHFs) with different M-n values were synthesized by cationic ring-opening polymerization (CROP) using Lewis acid catalysts and diols as initiators. The copolymerization process was found to be a statistical copolymer and the properties of the obtained PBO-stat-PTHFs make them suitable as lubricant base oils and additives. The study also showed that the PBO-stat-PTHFs have excellent miscibility with polyalphaolefin (PAO) and can significantly improve the viscosity index of PAO.
EUROPEAN POLYMER JOURNAL
(2022)
Article
Geology
Nuerkanati Madayipu, Huan Li, Thomas J. Algeo, Safiyanu Muhammad Elatikpo, Han Zheng, Qian-Hong Wu, Yuan-Lin Chen, Wen -Bo Sun
Summary: In this study, the less-studied tourmaline minerals from the Lianyunshan Complex were analyzed to understand the process of pegmatite-related Nb-Ta mineralization. The results show that tourmalines in the complex precipitated from evolved melts and exhibit specific chemical characteristics. Fluid fractionation may have played a role in the precipitation of the tourmalines, as indicated by the decreasing Mg and Ti contents. Additionally, the enriched Li and Sn contents in certain tourmalines are linked to different magmatic sources.
ORE GEOLOGY REVIEWS
(2023)
Article
Engineering, Chemical
Steven Ghambi, Sergio Sanchez-Segado, Vitalis Chipakwe, Animesh Jha
Summary: This research introduces a novel chemical process for the extraction and refining of columbite and tantalite concentrates, resulting in a purified mixture of oxides of Nb2O5 and Ta2O5. By reducing and magnetically separating iron oxides in the concentrates, the process successfully reclaim alkali complex formed during the roasting process as a purified mixture of Nb2O5 and Ta2O5 oxides.
MINERALS ENGINEERING
(2021)
Article
Environmental Sciences
Zahra Eshaghi Gorji, Abbas Ali Khodadadi, Siavash Riahi, Timo Repo, Yadollah Mortazavi, Marianna Kemell
Summary: In this study, a series of organic compounds were immobilized on N-doped graphene quantum dots to prepare a multifunctional organocatalyst for the coupling reaction between CO2 and propylene oxide. The proposed catalysts demonstrated high activity and yielded excellent results under optimal conditions.
JOURNAL OF ENVIRONMENTAL SCIENCES
(2023)
Article
Chemistry, Applied
Giulio Bresciani, Lorenzo Biancalana, Stefano Zacchini, Guido Pampaloni, Gianluca Ciancaleoni, Fabio Marchetti
Summary: The catalytic activity of a series of diiron complexes based on the {Fe2Cp2(CO)(x)} core (x = 2-3) and containing a bridging aminocarbyne ligand was screened in the transfer hydrogenation reaction of cyclohexanone from isopropanol. The best catalyst among these complexes was [Fe2Cp2(CN)(CO)(mu-CO){mu-CN(Me)(4-C6H4OMe)}], 3a, which exhibited moderate activity and showed a carbyne-centered mechanism, stabilized by the cyanide co-ligand, as supported by DFT calculations and IR analyses.
APPLIED ORGANOMETALLIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Alberto Gobbo, Xinyuan Ma, Gianluca Ciancaleoni, Stefano Zacchini, Lorenzo Biancalana, Massimo Guelfi, Guido Pampaloni, Steven P. Nolan, Fabio Marchetti
Summary: The potential of ruthenium(II) arene complexes in catalytic transfer hydrogenation has been widely investigated, but studies on homologous compounds with tris(1-pyrazolyl)methane (tpm) ligand are lacking. In this study, RuCl(kappa(3)-tpm)(PPh3)(2)]Cl reacted with various nitrogen ligands to form [RuCl(kappa(3)-tpm)(PPh3)(L)]Cl (L=NCMe, NCPh, imidazole) in nearly quantitative yields. These complexes were evaluated as catalytic precursors in the transfer hydrogenation of ketones, and complex 2 exhibited the highest activity.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Lorenzo Bonaldi, Marco Bortoluzzi, Stefano Zacchini, Guido Pampaloni, Fabio Marchetti, Lorenzo Biancalana
Summary: The chemistry of 1,2,4,5-tetrazines has attracted attention in the synthesis and application field. Recent studies have shown that regioselective reactions with alkynes and alkenes are favored when the tetrazine ring is coordinated to certain metal centers. This study explores the reactivity of tetrazines with chalcogenocyanate anions and demonstrates the formation of new heterocycles. The resulting ruthenium complexes were characterized using various analytical and spectroscopic techniques.
INORGANIC CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Giulio Bresciani, Stefano Zacchini, Guido Pampaloni, Marco Bortoluzzi, Fabio Marchetti
Summary: Diiron mu-aminocarbyne complexes can be synthesized by reacting sodium cyanate and tetrabutylammonium thiocyanate with pre-prepared diiron aminocarbyne complexes, yielding different substituted diiron cyanide complexes with yields of 67-81%, through substitution of the acetonitrile ligand. When reacted with potassium selenocyanate at reflux temperature, cyanide complexes can be obtained with yields of 45-67%. When reacted at room temperature in acetone, a small amount of potassium selenocyanate complexes can be obtained. All products were fully characterized and the chiral structure was determined by single crystal X-ray diffraction. DFT calculations shed light on the coordination mode and stability of the {NCSe-} fragment.
Article
Chemistry, Inorganic & Nuclear
Chiara Saviozzi, Sara Stocchetti, Giulio Bresciani, Lorenzo Biancalana, Guido Pampaloni, Fabio Marchetti
Summary: The reactions between diiron aminocarbyne complexes and primary amines resulted in the replacement of the acetonitrile ligand and the formation of new diiron complexes. The diiron-oxazolidinone conjugate was also successfully prepared. However, the reactions with NHEt2 in the presence of Me3NO led to unstable products. The behavior of the diiron complexes in aqueous media was also studied.
Article
Chemistry, Inorganic & Nuclear
Giulio Bresciani, Serena Boni, Tiziana Funaioli, Stefano Zacchini, Guido Pampaloni, Natalia Busto, Tarita Biver, Fabio Marchetti
Summary: We synthesized and evaluated the anticancer potential of two series of diruthenium biscyclopentadienyl carbonyl complexes. Novel dimetallacyclopentenone compounds (2-4) were obtained from the thermal reaction of [Ru2Cp2(CO)(μ-CO)(μ-η^1:η^3-C(Ph)C(Ph)C(O)}], 1, with alkynes HCCR [R = C5H4FeCp (Fc), 3-C6H4(Asp), 2-naphthyl; Cp = η(5)-C5H5, Asp = OC(O)-2-C6H4C(O)Me]. The resulting complexes showed cytotoxic activity against cancer cells, different interactions with nucleic acids, and production of ROS.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Giulio Bresciani, Jan Vanco, Tiziana Funaioli, Stefano Zacchini, Tomas Malina, Guido Pampaloni, Zdenek Dvorak, Zdenek Travnicek, Fabio Marchetti
Summary: Diruthenacyclopentenone complexes were synthesized and characterized. The complexes exhibited stronger cytotoxicity than cisplatin against various cancer cell lines, with the 17α-estradiol derived complex showing the highest activity. Further studies revealed that some complexes affected the cell cycle, apoptosis, oxidative stress, and autophagy.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Giulio Bresciani, Stefania Volante, Lorenzo Biancalana, Stefano Zacchini, Guido Pampaloni, Fabio Marchetti
Summary: Complexes [FeCpI(CO)(CNR)] and [FeCpI(CNR)2] were synthesized in 58-73% yields through the thermal reactions of [FeCpI(CO)2] with one/two equivalents of CNR, respectively, in the presence of [Fe2Cp2(CO)4] as catalyst. The catalytic potential of 1, 2a-f, and 3a-f in the bulk polymerization of rac-lactide was examined.
JOURNAL OF ORGANOMETALLIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Silvia Schoch, Giulio Bresciani, Chiara Saviozzi, Tiziana Funaioli, Marco Bortoluzzi, Guido Pampaloni, Fabio Marchetti
Summary: The reactivity of diiron bis-cyclopentadienyl cationic complexes containing a vinyliminium ligand coordinated to a diiron scaffold and decorated with a ferrocenyl group, [1a-g]CF3SO3, was investigated towards NBu4CN and NaBH4. Various addition products were obtained depending on the nature of the iminium substituents. The products were characterized using analytical and spectroscopic methods, and the molecular structures and thermodynamics were studied using DFT calculations.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Physical
Roberta Colaiezzi, Chiara Saviozzi, Nicola di Nicola, Stefano Zacchini, Guido Pampaloni, Marcello Crucianelli, Fabio Marchetti, Andrea Di Giuseppe, Lorenzo Biancalana
Summary: The reductive N-monomethylation of nitroarenes can be conveniently realized in one-pot using methanol as the reductant, methylating agent, and solvent. New ruthenium(II) arene complexes were developed as efficient catalytic precursors for the tandem reduction/N-methylation of aromatic nitrocompounds with methanol, starting from commercially available and inexpensive dioxime ligands.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Beatrice Campanella, Simona Braccini, Giulio Bresciani, Michele De Franco, Valentina Gandin, Federica Chiellini, Alessandro Pratesi, Guido Pampaloni, Lorenzo Biancalana, Fabio Marchetti
Summary: Diiron vinyliminium complexes are promising organometallics with potential anticancer activity. The synthesis and evaluation of [Fe2Cp2(CO)(mu-CO){mu-eta(1):eta(3)-C(R-3)C(R-4)CN(R-1)(R-2)}]CF3SO3 (2a-c, 4a-d) complexes were performed, including their solubility in D2O, Log P-ow, stability in D2O/Me2SO-d(6) mixture, and antiproliferative activity against ovarian cancer cell lines A2780 and A2780cisR, as well as the nontumoral cell line Balb/3T3 clone A31. The cytotoxicity data of 50 vinyliminium complexes were correlated with the structural properties, showing a positive correlation between octanol-water partition coefficient and relative antiproliferative activity on ovarian cancer cell lines. However, the effects of different substituents provided guidelines for the development of novel, more effective compounds. Three additional complexes (4p-r) were designed, synthesized, and biologically investigated, revealing their ability to inhibit thioredoxin reductase enzyme and induce cancer cell production of reactive oxygen species.
