• Mohammad Kassem, Maria Bokova, Andrey S. Tverjanovich, Daniele Fontanari, David Le Coq, Anton Sokolov, Pascal Masselin, Shinji Kohara, Takeshi Usuki, Alex C. Hannon, Chris J. Benmore and Eugene Bychkov*, Bent HgI2 Molecules in the Melt and Sulfide Glasses: Implications for Nonlinear Optics, Chem. Mater. 2019. DOI: 10.1021/acs.chemmater.9b00860

    Nonlinear optical (NLO) crystals are widely used in advanced photonic technologies for second harmonic and difference frequency generation (SHG and DFG, respectively), producing coherent light at frequencies where existing lasers are unavailable. Isotropic glasses do not exhibit SHG or DFG, except temporarily induced anisotropy under external stimuli. However, recent reports on glasses with chiral structural motifs show promising permanent NLO properties. We propose an alternative solution: hybrid molecular/network glasses with noncentrosymmetric HgI2 monomers. Mercury(II) iodide consists of linear HgI2 triatomic molecules in the vapor phase and in the yellow orthorhombic polymorph stable above 400 K. At lower temperatures, the tetragonal red form is composed of corner-sharing HgI4/2 tetrahedra forming a layered extended framework...

  • Dan Wang, Lihui Xiao, Peixia Yang,* Zhengrui Xu, Xiangyu Lu, Lei Du,* Oleg Levin, Liping Ge, Xiaona Pan, Jinqiu Zhang and Maozhong An, Dual-nitrogen-source engineered Fe–Nx moieties as a booster for oxygen electroreduction, J. Mater. Chem. A, 2019, 7, 11007-11015. DOI: 10.1039/C9TA01953G

    Metal–air batteries, particularly Zn–air batteries, have triggered considerable enthusiasm of communities due to their high theoretical power density. Developing highly active, cost-effective and alternative non-precious metal catalysts for the oxygen reduction reaction (ORR) is pivotal for popularizing zinc–air batteries. The rational design and synthesis of this type of catalyst are therefore critical, but it is still challenging to control the well-defined active sites as expected. Herein, we report a dual-nitrogen-source mediated route for synergistically controlling the formation of active Fe–Nx moieties that are embedded in the carbon matrix...

  • Maartje J.Levels, Cynthia M.Fehres, Lisa G.M. van Baarsen, Nathalie O.P. van Uden, Kristine Germar, Tom G.O'Toole, Iris C.J.Blijdorp, Johanna F.Semmelink, Marieke E.Doorenspleet, Arjen Q.Bakker, Mikhail Krasavin, Alexey Tomilin, Sophie Brouard, Hergen Spits, Dominique L.P.Baeten, Nataliya G.Yeremenko, BOB.1 controls memory B-cell fate in the germinal center reaction, J. Autoimmun. 2019. DOI: 10.1016/j.jaut.2019.04.011

    During T cell-dependent (TD) germinal center (GC) responses, naïve B cells are instructed to differentiate towards GC B cells (GCBC), high-affinity long-lived plasma cells (LLPC) or memory B cells (Bmem). Alterations in the B cell-fate choice could contribute to immune dysregulation leading to the loss of self-tolerance and the initiation of autoimmune disease. Here we show that mRNA levels of the transcription regulator BOB.1 are increased in the lymph node compartment of patients with rheumatoid arthritis (RA), a prototypical autoimmune disease caused by the loss of immunological tolerance. Investigating to what extent levels of BOB.1 impact B cells during TD immune responses we found that BOB.1 has a crucial role in determining the B cell-fate decision. High BOB.1 levels promote the generation of cells with phenotypic and functional characteristics of Bmem. Mechanistically, overexpression of BOB.1 drives ABF1 and suppresses BCL6, favouring Bmem over LLPC or recycling GCBC. Low levels of BOB.1 are sufficient for LLPC but not for Bmem differentiation...

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D.V.Zhuzhelskii, E.G.Tolstopjatova, S.N.Eliseeva, A.V.Ivanov, ShouleiMiao, V.V.Kondratiev, Electrochemical properties of PEDOT/WO3 composite films for high performance supercapacitor application, Electrochimica Acta, 2019, V.209, P.182-190. DOI: 10.1016/j.electacta.2019.01.007

Abstract

Tungsten oxide was electrochemically deposited from a metastable acidic solution of isopolytungstate on glassy carbon electrodes coated by the films of a conducting polymer poly-3,4-ethylenedioxythiophene (PEDOT). The formation of PEDOT/WO3 composite films during electrochemical deposition of tungsten oxide into the polymer matrix was gravimetrically monitored by EQCM. The morphology of WO3 deposits was studied using SEM, TEM and EDX analysis, including element mapping and depth concentration profile of main elements. SEM and TEM images of PEDOT/WO3 composites show disperse distribution of WO3 precipitates in the porous matrix of PEDOT, possessing high surface area and pore volume, effective for charge transport. Electrochemical behavior of PEDOT/WO3 was investigated in 0.5 M H2SO4 by cyclic voltammetry, galvanostatic charge-discharge method and electrochemical impedance spectroscopy. The WO3 component in the obtained PEDOT/WO3 composite electrodes exhibited high specific capacitance of 689 F g−1 in the potential range −0.3–0.0 V. The work presents a simple approach for the synthesis of PEDOT/WO3 composites with high values of specific capacitance. The obtained results indicate that PEDOT/WO3 composite could be a promising electrode material for supercapacitor applications.


Anton V. Rozhkov, Mariya A. Krykova, Daniil M. Ivanov, Alexander S. Novikov, Anna A. Sinelshchikova, Marina V. Volostnykh, Mikhail A. Konovalov, Mikhail S. Grigoriev, Yulia G. Gorbunova, Vadim Yurievich Kukushkin, Reverse Arene Sandwich Structures Based upon π‐hole•••[MII] (d8M = Pt, Pd) Interactions, where Positively Charged Metal Centers Play the Role of a Nucleophile, Angew. Chem. Int. Ed., Accepted Author Manuscript. DOI: 10.1002/ange.201814062

Abstract

The complexes [Pt(tpp)] (M = Pt; H2tpp = tetraphenyl‐porphyrin), [M(acac)2] (M = Pd, Pt, Hacac = acetylacetone), and [Pd(ba)2] (Hba = benzoylacetone) were co‐crystallized with highly electron‐deficient arene systems to form reverse arene sandwich structures built by π‐hole•••[MII] (d8M = Pt, Pd) interactions. The adduct [Pt(tpp)]•2C6F6 is monomeric, whereas the diketonate 1:1 adducts form columnar infinity 1D‐stack assembled by simultaneous action of both π‐hole•••[MII] and C–F interactions. The reverse sandwiches are based on noncovalent interactions and calculated ESP distributions indicate that in π‐hole•••[MII] contacts, [MII] plays the role of a nucleophile.


Kamran T.Mahmudov, Vadim Yu.Kukushkin, Atash V.Gurbanova, Mikhail A.Kinzhalov, Vadim P.Boyarskiy, M. Fátima C. Guedesda Silva, Armando J.L.Pombeiro, Isocyanide metal complexes in catalysis, Coordination Chemistry Reviews, 384, 65–89, 2019. DOI: 10.1016/j.ccr.2019.01.002

Abstract

The catalytic applications of isocyanide metal systems (from early to late transition metals) for organic transformations were systematically reviewed, and the studied transformations are also classified by type regardless of the metal center. A broad range of catalytic reactions of organic substrates has been developed including reactions of alkenes and alkynes, functionalization of E–H and E–E to multiple bonds, alkyl- and aryl-halides activation, nucleophilic addition, electron transfer catalysis, and photochemical reactions. This report gives a general overview of reaction routes, mechanisms, and driving forces and highlights the potential of isocyanide metal species, drawing attention to emerging putative targets.

Ответственный за содержание сайта Института химии: Роман Зумберов, r.zumberov@spbu.ru