Article
Chemistry, Physical
Dennis Milesevic, Joseph Stimson, Divya Popat, Patrick Robertson, Claire Vallance
Summary: In this study, the ultraviolet dissociation of tetrahydrofuran (THF) was investigated using velocity-map imaging. Excitation to the S1 state was found to lead to ring opening and formation of different products. Channel 2 products were found to be unstable and further dissociated into CH3 and CHO. The velocity and angular distributions of the observed dissociation products indicated the importance of the dissociation timescale of the diradical intermediate.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Multidisciplinary Sciences
Amaury Bossion, Chen Zhu, Lea Guerassimoff, Julie Mougin, Julien Nicolas
Summary: The authors demonstrate a system based on acrylamide and cyclic ketene acetals to obtain copolymers with faster degradation rates, which have potential applications in drug release and environmental fields.
NATURE COMMUNICATIONS
(2022)
Review
Chemistry, Inorganic & Nuclear
David S. Glueck
Summary: The hydration of nitriles is catalyzed by both enzymes with iron or cobalt active sites and various synthetic metal complexes. This study focuses on the similarities between the reaction mechanisms of the enzyme and a specific class of highly active catalysts bearing secondary phosphine oxide (SPO) ligands. Both mechanisms involve intramolecular attack on a coordinated nitrile, resulting in the formation of an amide.
DALTON TRANSACTIONS
(2021)
Article
Polymer Science
Tomoki Nara, Arihiro Kanazawa, Sadahito Aoshima
Summary: The cationic copolymerizations of styrene derivatives and benzaldehyde were studied to achieve alternating copolymerization and create degradable polystyrene derivatives. The copolymerization of p-methylstyrene and benzaldehyde was found to proceed in a living manner with GaCl3 as a catalyst, producing a copolymer with an alternating sequence and controllable molecular weight. The copolymer exhibited the formation of sec-benzylic ether structures, leading to its degradation under acidic conditions.
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
Polymer Science
Wenqi Wang, Brayan Rondon, Zeyu Wang, Junpeng Wang, Jia Niu
Summary: The study reports a general method for the organocatalyzed photocontrolled radical ring-opening cascade copolymerization of macrocyclic allylic sulfone and various types of vinyl monomers. This method provides a versatile approach to the wide range of degradable vinyl plastics with various structures and functions.
Article
Materials Science, Multidisciplinary
Huan Wang, Xiao-Ping Ma, Xiang-Yu Zeng, Jing Gong, Jun-Fa Lin, Xiao-Yan Wang, Zheng-Yi Dai, Kun Han, Yi-Ting Wang, Tian-Long Xia
Summary: The recent discoveries of large anomalous Hall effect (AHE) and topological Hall effect (THE) in antiferromagnets have led to intense study in theories and experiments. In this study, the magnetic and electrical transport properties of a layered antiferromagnet V0.3NbS2 were investigated. The material showed antiferromagnetic order below 53 K and exhibited weak magnetic hysteresis with a small net magnetization along the c axis. AHE was observed in this antiferromagnet, which is of particular interest due to the near-perfect cancellation of moment. THE was also detected at low temperatures, acting as a probe for spin reorientation in the magnetization process induced by field. This study provides a platform for studying AHE in antiferromagnets.
Article
Chemistry, Multidisciplinary
Hyuk-Joon Jung, Chatura Goonesinghe, Parisa Mehrkhodavandi
Summary: In this study, we report the alternating copolymerization of caprolactone and epoxide through the in situ formation of pre-sequenced spiroorthoester monomer. The reaction is catalyzed by a temperature triggered, bifunctional cationic indium complex. The resulting poly(ether-alt-ester) can be further modified and degraded.
Article
Environmental Sciences
Min Huang, Ke Hu, Xiang Li, Yun Wang, Jinbo Ouyang, Limin Zhou, Zhirong Liu
Summary: The recovery of radionuclides from tantalum-niobium slag is important for sustainable development, and roasting at 500 degrees Celsius proves to be an effective method for improving the leaching ratio of uranium and thorium.
Editorial Material
Chemistry, Inorganic & Nuclear
Chenxi Duan, Yuli Gao, Shangtao Chen, Fenghua Zu, Jianying Zhang, Chunming Cui
Summary: An efficient one-pot synthesis of tetraaryl alpha-diimines with various aryl groups via TiCl4-mediated C-C coupling of imidoylstannanes followed by dioxygen oxidation in the presence of KF has been described. The protocol is suitable for the synthesis of valuable alpha-dimines with bulky aryl groups on the nitrogen atoms. The bulky tetraaryl dimine 2a could be prepared on a gram scale and has been utilized for the synthesis of the corresponding N-heterocyclic silylene. The reaction intermediates, an eta(2)-iminoacyl titanium trichloride and an alpha-diamide titanium dichloride, have been isolated and characterized by single-crystal X-ray diffraction studies.
Article
Geochemistry & Geophysics
Zihu Lv, Hongwei Cheng, Min Wei, Dengkui Zhao, Dongyin Wu, Changmiao Liu
Summary: By analyzing a Ta-Nb-Li-Rb rare metal deposit in Jiangxi Province, it was found that the main useful elements in the ore are tantalum, niobium, lithium, and rubidium, which are mainly present in columbite and zinnwaldite. The beneficiation evaluation based on the mineralogical characteristic suggests that these rare metal resources, as well as other non-metallic resources in the ore, can be effectively recovered using gravity, magnetic, and flotation separation methods.
Article
Metallurgy & Metallurgical Engineering
S. M. Masloboeva, L. G. Arutyunyan, M. N. Palatnikov, D. V. Manukovskaya
Summary: High recovery rates of tantalum and niobium were achieved by leaching a plumbomicrolite concentrate with mixtures of HF and H2SO4, HF and HNO3 acids. The use of fluoride-sulfuric acid and fluoride-nitric acid schemes, along with extractive separation techniques, led to the production of high-purity tantalum compounds that meet impurity content standards. The profitability of the processing scheme ultimately determines the final choice for PMC treatment.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2021)
Article
Engineering, Chemical
Jean Baptiste Habinshuti, Jeanne Pauline Munganyinka, Tanvar Himanshu, Adelina. R. Adetunji, Brajendra Mishra, Janvier Mukiza, Grace Ofori-Sarpong, Azikiwe P. Onwualu
Summary: We conducted a fluoride-free comparative study on the extraction of Nb and Ta from Nigerian and Rwandan columbite-tantalite concentrates. The alkali-assisted roasting with KOH at optimum conditions facilitated the solubility of (Nb-Ta)-minerals, with the Nigerian sample being more soluble than the Rwandan sample. Guanidine carbonate was used to extract Nb and Ta from the pregnant leach solution, resulting in high purity mixed oxides. This study presents a promising alternative to HF for the sustainable extraction of Nb and Ta.
MINERALS ENGINEERING
(2023)
Article
Chemistry, Inorganic & Nuclear
D. M. Ramitha Y. P. Rupasinghe, Makayla R. Baxter, Matthias Zeller, Suzanne C. Bart
Summary: This article presents the synthesis and crystal structure of homoleptic tetrabenzylthorium, as well as the isolation and characterization of several other new tetrabenzyl complexes. It also reports the synthesis and updated structural data of a phosphine adduct of tetrabenzylthorium. The utility of tetrabenzylthorium as a synthon for other organothorium compounds is also discussed.
Article
Environmental Sciences
S. Sutliff-Johansson, S. Ponter, E. Engstrom, I Rodushkin, P. Peltola, A. Widerlund
Summary: This study evaluates the temporal trends of Tantalum (Ta) and Niobium (Nb) concentrations in northern Baltic Sea sediments, with a focus on the potential impact from the Ronnskar sulfide ore smelter in Sweden. Ta concentrations increased significantly near the smelter due to electronic waste processing, while Nb concentrations remained stable. Anthropogenic Ta showed associations with hydrous ferric oxides and organic matter, while Nb did not display notable changes.
JOURNAL OF SOILS AND SEDIMENTS
(2021)
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
Polymer Science
Giovanni Ricci, Giuseppe Leone, Giorgia Zanchin, Francesco Masi, Stefano Zacchini, Giulio Bresciani, Massimo Guelfi, Guido Pampaloni
Summary: Novel copper complexes were synthesized by reacting copper(II) dichloride and copper(II) dibromide with pyridyl-imine ligands with different substituents. The complexes were characterized and their molecular structure was determined. When combined with methylaluminoxane (MAO), the complexes acted as active and selective catalysts for the polymerization of 1,3-dienes, resulting in polymers with unusual structures.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(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 Zappelli, Gianluca Ciancaleoni, Stefano Zacchini, Fabio Marchetti
Summary: In this study, the authors investigated the reactions of [Fe2Cp2(CO)(mu-CO){mu-eta 1:eta 3-C gamma(Fc)-C beta HC alpha(CN)NMe2}] complex with isocyanides (CNR). They were able to characterize and understand the structure and properties of the resulting products.
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
Lorenzo Marchi, Simone Fantuzzi, Andrea Cingolani, Alessandro Messori, Rita Mazzoni, Stefano Zacchini, Marina Cocchi, Luca Rigamonti
Summary: Iron(ii) bis-pyrazolilpyridyl (bpp-R) complexes [Fe(bpp-R)(2)](X)(2)·solvent undergo spin transition from high spin (S = 2, HS) to low spin (S = 0, LS) in the solid state, known as spin crossover (SCO). The distortion of the octahedral coordination environment is affected by crystal packing and modulates the SCO behavior. This study used a multivariate approach combining Principal Component Analysis and Partial Least Squares regression to analyze the structural data of HS structures and efficiently model and predict the spin transition temperature T-1/2 for complexes with different R groups, X- anions, and co-crystallized solvents.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Sara Benetti, Maria Dalla Pozza, Lorenzo Biancalana, Stefano Zacchini, Gilles Gasser, Fabio Marchetti
Summary: Novel diiron vinyliminium complexes were synthesized and characterized by various spectroscopic techniques. Their solubility in D2O, Log Pow coefficients, and stability in aqueous media were determined. The antiproliferative activity of these complexes on cancer cell lines was evaluated and their mechanism of action was investigated by assessing their influence on mitochondrial respiration.
DALTON TRANSACTIONS
(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.