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Jae-Hun Jeoung, Berta M Martins, Holger Dobbek
Carbon monoxide dehydrogenases (CODHs) are central players in the biogeochemical carbon monoxide (CO) cycle and have been extensively studied from the ecological level to the structural/molecular level. Of the two types of CODHs, the oxygen-tolerant CODHs use a bimetallic [CuSMo(=O)OH] center connected to the protein via a pyranopterin cofactor, whereas the oxygen-sensitive CODHs contain a [NiFe4 S4 -OHx ]-cluster. Despite the fact that we have a basic understanding of how both types of CODHs use distinct active sites to catalyze the oxidation of CO with water to CO2 , two protons, and two electrons (a reversible reaction in the cases of the oxygen-sensitive CODHs), many questions remain unanswered, especially concerning the electronic structures of the intermediate states...
2019: Methods in Molecular Biology
Emmanuel Salomon, Marjorie Schmitt, Anil Kumar Marapaka, Athanasios Stamogiannos, Germain Revelant, Céline Schmitt, Sarah Alavi, Isabelle Florent, Anthony Addlagatta, Efstratios Stratikos, Céline Tarnus, Sébastien Albrecht
The synthesis of racemic substituted 7-amino-5,7,8,9-tetrahydrobenzocyclohepten-6-one hydrochlorides was optimized to enhance reproducibility and increase the overall yield. In order to investigate their specificity, series of enzyme inhibition assays were carried out against a diversity of proteases, covering representative members of aspartic, cysteine, metallo and serine endopeptidases and including eight members of the monometallic M1 family of aminopeptidases as well as two members of the bimetallic M17 and M28 aminopeptidase families...
October 11, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Daeok Kim, Kyung Seob Song, Onur Buyukcakir, Taner Yildirim, Ali Coskun
We demonstrated that the ratio and position of two different metal ions, Pd and Cu, can be precisely controlled within MOFs through predesigned metal clusters. These MOF structures incorporating Pd-Cu paddle wheel units were synthesised simply by reacting Pd-Cu acetate metal clusters and tritopic organic linkers at room temperature. Pd-Cu open metal sites were found to be uniformly distributed throughout the MOFs with a ca. 1 : 1 ratio. The incorporation of Pd into the MOF structure also led to enhanced affinity towards H2 with Qst values up to 8...
October 12, 2018: Chemical Communications: Chem Comm
Nan Zhou, Fangfang Su, Chuanpan Guo, Linghao He, Zhankui Jia, Minghua Wang, Qiaojuan Jia, Zhihong Zhang, Siyu Lu
Fabricating novel bimetallic metal organic framework (MOF) architectures and exploiting them as aptasensor scaffolds for detecting diverse analytes, especially cancer markers, have aroused widespread research attention. Herein, we report a novel strategy for obtaining ZnZr bimetallic MOFs via the MOF-on-MOF method and exploit them as an aptasensor platform for detecting the cancer marker protein tyrosine kinase-7 (PTK7). Basic characterizations reveal that the chemical structure, crystalline properties, and surface functionality of bimetallic ZnZr-MOFs can be modulated by changing the order of addition of metal precursors and organic ligands...
September 22, 2018: Biosensors & Bioelectronics
Alexandre Sodreau, Sonia Mallet-Ladeira, Sebastien Lachaize, Karinne Miqueu, Jean-Marc Sotiropoulos, David Madec, Céline Nayral, Fabien Delpech
The synthesis of iron germanide nanoparticles at the nanoscale is a challenging task. Here, we describe the preparation of nanocrystals of the hexagonal Fe1.67Ge phase via the thermolysis of single source precursors [{iPrNC(tBu)NiPr}RGe]Fe(CO)4 (where R = Cl, N(SiMe3)2) under mild conditions (200 °C). These bimetallic precursors and the corresponding germylenes [{iPrNC(tBu)NiPr}RGe] were fully characterized by spectroscopic techniques as well as single crystal X-ray diffraction. While the structural features of the molecular species were shown to be almost identical, the results of the thermolysis were highly dependent on the nature of R...
October 11, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
G Muthuraman, A G Ramu, Y H Cho, E J McAdam, I S Moon
Remediation of electronic gas CF4 using commercially available technologies results in another kind of greenhouse gas and corrosive side products. This investigation aimed to develop CF4 removal at room temperature with formation of useful product by attempting an electrogenerated Cu1+ [Ni2+ (CN)4 ]1- mediator. The initial electrolysis of the bimetallic complex at the anodized Ti cathode demonstrated Cu1+ [Ni2+ (CN)4 ]1- formation, which was confirmed by additional electron spin resonance results. The degradation of CF4 followed mediated electrochemical reduction by electrogenerated Cu1+ [Ni2+ (CN)4 ]1- ...
October 10, 2018: Waste Management & Research
Changguang Yao, Priyanka Chakraborty, Emanuele Aresu, Huaifeng Li, Chao Guan, Chunhui Zhou, Lan-Chang Liang, Kuo-Wei Huang
A terminal nickel hydroxide complex (PN3P)Ni(OH) (3) bearing the 2nd generation phosphorus-nitrogen PN3P-pincer ligand has been synthesized and structurally characterized. As a nucleophile, 3 reacts with CO to afford the hydroxycarbonyl complex 4, (PN3P)Ni(COOH). 3 can also activate CO2 and CS2 to produce nickel bicarbonate (PN3P)Ni(OCOOH) (5) and bimetallic dithiocarbonate [(PN3P)NiS]2CO (6) respectively, as well as to promote aryl isocyanate and isothiocyanate insertion into the Ni-OH bond to give the corresponding (PN3P)NiEC(O)NHAr complexes (E = O, 7; E = S, 8)...
October 10, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Jin Xie, Kohei Sekine, Sina Witzel, Petra Krämer, Matthias Rudolph, Frank Rominger, A Stephen K Hashmi
Organoboron compounds are versatile synthetic building blocks. We herein report a new strategy, a photochemical gold-catalyzed chemo-selective Hiyama arylation of B,Si bimetallic reagents with diazonium salts, which is orthogonal to common strategies and therefore a unique tool for synthesis of valuable biarylboronates. With this new methodology a wide array of diversely functionalized sp2- and sp3-hybridized biarylboronates were obtained. Notably, the synergism of gold catalysis with copper catalysis or palladium catalysis, allows for one-pot iterative C-X (heteroatom) and C-C couplings for the rapid assembly of several simple fragments to relatively complex molecules...
October 9, 2018: Angewandte Chemie
Changda Li, Haitong Tang, Yu Fang, Zhifeng Xiao, Kunyu Wang, Xiang Wu, Helin Niu, Chengfeng Zhu, Hong-Cai Zhou
In this study, we demonstrate a bottom-up assembly of a monomeric copper complex and a two-dimensional (2-D) heterometallic metal-organic framework (MOF) from a carboxylate-functionalized tridentate Schiff base ligand and metal ions. The obtained 2-D MOF features a unique bimetallic copper center which is different from its monometallic precursor and acts as an efficient heterogeneous catalyst for the Friedel-Crafts reaction and Henry reaction. The MOF catalyst shows a remarkably superior activity compared to its homogeneous counterparts in a wide range of substrates...
October 9, 2018: Inorganic Chemistry
Pei Zhang, Xiudong Zhang, Xinchen Kang, Huizhen Liu, Chunjun Chen, Chao Xie, Buxing Han
A method to synthesize bimetallic alloys with tunable morphologies and controlled structural defects was proposed using the characteristics of emulsions tailored by salts. AuPd and PtPd nanowire networks with abundant structural defects exhibited outstanding catalytic performances for oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid, because of the strong ability to generate radicals.
October 8, 2018: Chemical Communications: Chem Comm
Mahdiyeh Rashki Ghaleno, Mansour Ghaffari-Moghaddam, Mostafa Khajeh, Ali Reza Oveisi, Mousa Bohlooli
A bioinspired iron(III)porphyrinic Zr-MOF, PCN-222(Fe), was modified by post-synthetic cluster metalation with iron(III) chloride, as a cheap, earth-abundant, and environmentally friendly metal precursor, towards formation a new multifunctional MOF, namely Fe@PCN-222(Fe). The MOF consists of bimetallic (Zr-oxo-Fe) nodes linked by Fe(III)porphyrin struts. The cluster metalation and pre-activation treatment of PCN-222(Fe) were performed cooperatively using the FeCl3 . The respective MOF was characterized through various techniques, such as FT-IR, PXRD, ICP-AES, BET surface area, SEM, UV-Vis DRS, TGA/DSC, PL, and XPS analyses...
September 29, 2018: Journal of Colloid and Interface Science
Martin Kluenker, Bethany M Connolly, David M Marolf, Muhammad Nawaz Tahir, Karsten Korschelt, Paul Simon, Uta Köhler, Sergi Plana-Ruiz, Bastian Barton, Martin Panthöfer, Ute Kolb, Wolfgang Tremel
Controlling the morphology of noble-metal nanoparticles is mandatory to tune specific properties such as catalytic and optical behavior. Heterodimers consisting of two noble metals have been synthesized, so far mostly in aqueous media using selective surfactants or chemical etching strategies. We report a facile synthesis for Au@Pd and Pd@Au heterodimer nanoparticles (NPs) with morphologies ranging from segregated domains (heteroparticles) to core-shell structures by applying a seed-mediated growth process with Au and Pd seed nanoparticles in 1-octadecene (ODE), which is a high-boiling organic solvent...
October 5, 2018: Inorganic Chemistry
Zhongrui Chen, Gabriel Canard, Denis Jacquemin, Christophe Bucher, Michel Giorgi, Olivier Siri
We report the synthesis of a key mononuclear intermediate complex based on a quinoid ligand and its further metalation to afford the corresponding hetero-bimetallic compound that revealed unique properties. An unprecedented hetero-bimetallic effect in coordination chemistry could be indeed observed and exploited to prepare, through selective ligand exchange, a tetranuclear complex (Pd-Ni-Ni-Pd) absorbing light up to the far-red region. Most importantly, we describe here to the best of our knowledge the first use of bischelating ligand for ligand exchange, and this approach can be considered as a new route for incorporating planar units to access multi-heteronuclear complexes...
October 4, 2018: Inorganic Chemistry
Vineet Sadarangani, Safikur Rahman, Apurba Kumar Sau
Recent studies have highlighted the therapeutic importance of bimetallic human arginase-I against hyperargininemia and L-arginine auxotrophic cancers. The longer retention of catalytic activity of the Co2+ -enzyme than that of the Mn2+ in human serum is associated with its enhanced therapeutic potential. To understand the basis of this and also to explore the role of a bimetallic center as well as the role of individual metal ions in the stability, we performed a detailed biochemical and biophysical investigation...
November 2018: Biochimica et biophysica acta. Proteins and proteomics
Carlos A Rodríguez-Proenza, Juan P Palomares-Báez, Marco A Chávez-Rojo, Amado F García-Ruiz, Cristy L Azanza-Ricardo, Alan Santoveña-Uribe, Gabriel Luna-Bárcenas, José L Rodríguez-López, Rodrigo Esparza
Bimetallic nanoparticles are of interest since they lead to many interesting electrical, chemical, catalytic, and optical properties. They are particularly important in the field of catalysis since they show superior catalytic properties than their monometallic counterparts. The structures of bimetallic nanoparticles depend mainly on the synthesis conditions and the miscibility of the two components. In this work, PdPt alloyed-bimetallic nanoparticles (NPs) were synthesized through the polyol method, and characterized using spherical aberration (Cs) corrected scanning transmission electron microscopy (STEM)...
October 2, 2018: Materials
Lucy Gloag, Tania M Benedetti, Soshan Cheong, Christopher E Marjo, J Justin Gooding, Richard D Tilley
A major synthetic challenge is to make metal nanoparticles with nanosized branches and well-defined facets for high-performance catalysts. Herein, we introduce a mechanism that uses the growth of hexagonal crystal structured branches off cubic crystal structured core nanoparticles. We control the growth to form Pd-core Ru-branch nanoparticles that have nanosized branches with low index Ru facets. We demonstrate that the branched and faceted structural features of the Pd-Ru nanoparticles retain high catalytic activity while also achieving high stability for the oxygen evolution reaction...
October 2, 2018: Journal of the American Chemical Society
Roya Mirzajani, Somayeh Karimi
The magnetic Ni-Ag bimetallic nanoparticles supported on reduced graphene oxide (Ni-Ag NPs/rGO) was synthesized and characterized by transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), field emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometer (VSM). Subsequently, this magnetic hybrid material as a novel adsorbent was applied for the sonochemical simultaneous removal of sunset yellow and tartrazine dyes in combination with first-order derivative spectrophotometric method to resolve the overlap between the spectra of these dyes...
September 20, 2018: Ultrasonics Sonochemistry
Lidia I Godina, Alexey V Kirilin, Anton V Tokarev, Irina L Simakova, Dmitry Yu Murzin
Carbon-supported mono- and bimetallic catalysts prepared via incipient wetness impregnation were systematically studied in aqueous-phase reforming (APR) of xylitol aiming at hydrogen production from biomass. The catalytic performance of several VIII group metals and their combinations, such as Pt, Ni, Pt-Ni, Re, Pt-Re, Ru, Pt-Ru, and Pt-Co, was compared for xylitol APR in a fixed-bed reactor at 225 °C and 29.7 bar (N2 ). Ni/C, Ru/C, and Re/C catalysts displayed significantly lower activity compared to others...
February 14, 2018: Industrial & Engineering Chemistry Research
Anthony F Hill, Richard A Manzano, Jas S Ward
The reactions of the trimethylsilylpropargylidyne [W([triple bond, length as m-dash]CC[triple bond, length as m-dash]CSiMe3)(CO)2(Tp*)] (1: Tp* = hydrotris(dimethylpyrazolyl)borate) towards selenium centred reagents when treated with tetrabutylammonium fluoride (TBAF) were explored in order to prepare alkynylselenolato propargylidynes, e.g., [W([triple bond, length as m-dash]CC[triple bond, length as m-dash]CSePh)(CO)2(Tp*)]. Treating 1 with TBAF and PhSeSePh resulted in E and Z isomers of the vinylcarbyne (allylidyne) complex [W{[triple bond, length as m-dash]CC(SePh)[double bond, length as m-dash]CHSePh}(CO)2(Tp*)] in addition to traces of the trisubstituted derivative [W{[triple bond, length as m-dash]CC(SePh)[double bond, length as m-dash]C(SePh)2}(CO)2(Tp*)]...
October 1, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Koya Prabhakara Rao, Masakazu Higuchi, Suryachandram Jettiboina, Susumu Kitagawa
We demonstrate a new de novo synthetic methodology to achieve high temperature stable compelled composite superhydrophobic porous coordination polymers (PCPs). These new PCPs achieved based on coordination capabilities of 1st-row transition metal ions like Co2+, Ni2+, and Zn2+. The obtained composite PCPs containing, [Zn2M2O]6+ (M = Co or Ni) bimetallic cluster core with open metal sites (OMSs), exhibited distinct iso-steric heats of adsorption and surface areas due to the difference in their open metal Lewis acidic sites of solvent-free state...
September 29, 2018: Journal of the American Chemical Society
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