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Pitchaimani Veerakumar, Pounraj Thanasekaran, King-Chuen Lin, Shang-Bin Liu
Rhenium nanoparticles (ReNPs) supported on ordered mesoporous carbon (OMC) as a catalyst (Re/OMC) through a solvent-evaporation induced self-assembly (ELSA) method were prepared. The synthesized heterogonous catalyst was fully characterized using X-ray diffraction, field emission transmission electron microscopy, N2 sorption, metal dispersion, thermogravimetric analysis, Raman, Fourier-transform infrared, and X-ray photon spectroscopies. In addition, the catalyst was applied to reduce the aromatic nitro compounds (ANCs) for the first time in aqueous media and the reactions were monitored by following the intensity changes in the UV-vis absorption spectra with respect to time...
July 18, 2017: Journal of Colloid and Interface Science
Antoine Simonneau, Franck Le Bideau, Jean-Hugues Mirebeau, Jérôme Marrot, Gérard Jaouen
: After a short review dealing with bioorganometallic chemistry, the synthesis of tetracarbonyl (pyrrolylimine) complexes of rhenium bearing chirality on the pyrrolyl ligands was reported.The reactivity of these compounds towards the substitution of one carbonyl ligand with triphenyl phosphine, tricyclohexyl phosphine and trimethyl phosphite was studied. The rhenium becoming a stereogenic center in that transformation, the resulting tricarbonyl species were obtained as mixtures of diastereomers, with diastereomeric excesses varying from 8 to 84%, according to the reaction conditions and the relative steric hindrances of the pyrrolylimine and the organophosphorus ligands...
July 19, 2017: Current Topics in Medicinal Chemistry
Pedro L Esquinas, Carlos F Uribe, M Gonzalez, Cristina Rodríguez-Rodríguez, Urs O Häfeli, Anna Celler
The main applications of (188)Re in radionuclide therapies include trans-arterial liver radioembolization and palliation of painful bone-metastases. In order to optimize (188)Re therapies, the accurate determination of radiation dose delivered to tumors and organs at risk is required. Single photon emission computed tomography (SPECT) can be used to perform such dosimetry calculations. However, the accuracy of dosimetry estimates strongly depends on the accuracy of activity quantification in (188)Re images...
July 20, 2017: Physics in Medicine and Biology
Hyejin Jang, Christopher R Ryder, Joshua D Wood, Mark C Hersam, David G Cahill
ReS2 represents a different class of 2D materials, which is characterized by low symmetry having 1D metallic chains within the planes and extremely weak interlayer bonding. Here, the thermal conductivity of single-crystalline ReS2 in a distorted 1T phase is determined at room temperature for the in-plane directions parallel and perpendicular to the Re-chains, and the through-plane direction using time-domain thermoreflectance. ReS2 is prepared in the form of flakes having thicknesses of 60-450 nm by micromechanical exfoliation, and their crystalline orientations are identified by polarized Raman spectroscopy...
July 19, 2017: Advanced Materials
Jae Young Park, Hang-Eun Joe, Hyong Seo Yoon, SangHyuk Yoo, Taekyeong Kim, Keonwook Kang, Byung-Kwon Min, Seong Chan Jun
Rhenium disulfide (ReS2) has attracted immense interest as a promising two-dimensional material for optoelectronic devices owing to its outstanding photonic response based on its energy band gap's insensitivity to the layer thickness. Here, we theoretically calculated the electrical band structure of mono-, bi-, and tri-layer ReS2 and experimentally found the work function to be 4.8 eV, which was shown to be independent of the layer thickness. We also evaluated the contact resistance of a ReS2 field-effect transistor (FET) using a Y-function method with various metal electrodes, including graphene...
July 18, 2017: ACS Applied Materials & Interfaces
J D Castillo Gomez, A Hagenbach, U I M Gerling-Driessen, B Koksch, N Beindorff, W Brenner, U Abram
Potential tetradentate thiocarbamoylbenzamidine derivatives H4L have been synthesized from the corresponding benzimidoyl chlorides and triglycine. They are suitable chelating agents for the oxidotechnetium(v) and oxidorhenium(v) cores and form stable, neutral [MO(HL)] complexes with an equatorial SN3 coordination sphere and an additional, uncoordinated carboxylic group, which can be used for bioconjugation. Representatives of the rhenium and (99)Tc products have been isolated and analyzed with spectroscopic methods and X-ray diffraction...
July 12, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Kingsley Onyebuchi Obodo, Cecil Napthaly Moro Ouma, Joshua Tobechukwu Obodo, Moritz Braun
We investigate the structural, electronic and optical properties of transition metal doped triclinic monolayered rhenium disulfide and diselenide (ReS2 and ReSe2) by means of quantum mechanical calculations. The calculated electronic band gaps for ReS2 and ReSe2 monolayers are 1.43 eV and 1.23 eV, respectively, with both having a non-magnetic ground state. The calculated dopant substitutional energies under both Re-rich and X(S or Se)-rich conditions show that it is possible to experimentally synthesize transition metal doped ReX2 (where X is S or Se) monolayer systems...
July 12, 2017: Physical Chemistry Chemical Physics: PCCP
Tomasz Klemens, Katarzyna Czerwińska, Agata Szlapa-Kula, Slawomir Kula, Anna Switlicka, Sonia Kotowicz, Mariola Siwy, Katarzyna Bednarczyk, Stanisław Krompiec, Karolina Smolarek, Sebastian Maćkowski, Witold Danikiewicz, Ewa Schab-Balcerzak, Barbara Machura
Nine rhenium(i) complexes possessing three carbonyl groups together with a bidentate coordinated 2,6-di(thiazol-2-yl)pyridine derivative were synthesized to examine the impact of structure modification of the triimine ligand on the photophysical, thermal and electrochemical properties of [ReCl(CO)3(4-R(n)-dtpy-κ(2)N)]. The Re(i) complexes were fully characterized using IR, (1)H and (13)C, HRMS-ESI and single crystal X-ray analysis. Their thermal properties were evaluated using DSC and TGA measurements. Photoluminescence spectra of [ReCl(CO)3(4-R(n)-dtpy-κ(2)N)] were investigated in solution and in the solid state, at 298 and 77 K...
July 13, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Lewis S Hart, James L Webb, Sara Dale, Simon J Bending, Marcin Mucha-Kruczynski, Daniel Wolverson, Chaoyu Chen, José Avila, Maria C Asensio
ReSe2 and ReS2 are unusual compounds amongst the layered transition metal dichalcogenides as a result of their low symmetry, with a characteristic in-plane anisotropy due to in-plane rhenium 'chains'. They preserve inversion symmetry independent of the number of layers and, in contrast to more well-known transition metal dichalcogenides, bulk and few-monolayer Re-TMD compounds have been proposed to behave as electronically and vibrational decoupled layers. Here, we probe for the first time the electronic band structure of bulk ReSe2 by direct nanoscale angle-resolved photoemission spectroscopy...
July 11, 2017: Scientific Reports
Milovan Matovic, Dalibor Nikolic, Nenad Filipovic, Dongfang Chen, Marija Jeremic, Slobodan M Jankovic, Srdjan Ninkovic, Aleksandar Cvetkovic, Marina Vlajkovic, Ana Rankovic
OBJECTIVE: To describe a new method of 3D interactive modeling which integrates images obtained by separate SPET and multi slice computed tomography (MSCT) modalities using an original software in order to better localize SNL in BC patients. SUBJECTS AND METHODS: We used technetium-99m-colloid rhenium sulphate for identifying SNL in seven patients with BC. Markers were made of lead pearls wrapped with cotton wool soaked in (99m)Tc-pertechnetate and placed on the skin of the patients forming of a triangle...
July 12, 2017: Hellenic Journal of Nuclear Medicine
Basudeb Saha, Sibao Liu, Saikat Dutta, Weiqing Zheng, Nicholas S Gould, Ziwei Cheng, Bingjun Xu, Dionisios G Vlachos
Renewable jet-fuel ranged alkanes are synthesized by hydrodeoxygenation of lignocellulose derived high carbon furylmethanes over ReOx modified Ir/SiO2 catalysts under mild reaction conditions. Ir-ReOx/SiO2 with a Re/Ir molar ratio of 2 exhibits the best performance, achieving a combined alkanes yield of 82-99% from C12-C15 furylmethanes. Catalyst can be regenerated in three consecutive cycles with only ~12% loss in the combined alkanes yield. Mechanistically, the furan moieties of furylmethanes undergo simultaneous ring saturation and ring opening to form a mixture of complex oxygenates consisting of saturated furan rings, mono-keto groups, and mono-hydroxy groups...
July 7, 2017: ChemSusChem
Nicola Salvarese, Fiorenzo Refosco, Roberta Seraglia, Marco Roverso, Alessandro Dolmella, Cristina Bolzati
The synthesis and characterization of a new series of neutral, six-coordinated compounds [Re(III)X3(PNPR)], where X is Cl or Br and PNPR is a diphosphinoamine having the general formula (Ph2PCH2CH2)2NR (R = H, CH3, CH2CH3, CH2CH2CH3, CH2CH2CH2CH3 and CH2CH2OCH3) are reported. Stable [Re(III)X3(PNPR)] complexes were synthesized, in variable yields, starting from precursors where the metal was in different oxidation states (iii and v), by ligand-exchange and/or redox-substitution reactions. The compounds were characterized by elemental analysis, proton NMR spectroscopy, cyclic voltammetry, UV/vis spectroscopy, positive-ion electrospray ionization mass spectrometry (ESI(+)-MS) and X-ray diffraction analysis...
July 18, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Antonio Shegani, Charalampos Triantis, Berthold A Nock, Theodosia Maina, Christos Kiritsis, Vassilis Psycharis, Catherine Raptopoulou, Ioannis Pirmettis, Francesco Tisato, Minas S Papadopoulos
In the present work, we investigated potential means to obtain neutral tricarbonyl mixed-ligand fac-[M(CO)3L(1)L(2)] complexes (M = Re, (99m)Tc) containing the (2-hydroxyphenyl)diphenylphosphine (POH) bidentate ligand (L(1)H) and a series of monodentate ligands (L(2)). First, fac-[Re(CO)3(PO)(H2O)], 1, was synthesized by reaction of POH and [Et4N]2[Re(CO)3Br3] in equimolar amounts in MeOH at room temperature. Interestingly, with excess of POH this reaction afforded fac-[Re(CO)3(PO)(POH)], 2, with POH operating both as a bidentate and as a monodentate ligand...
July 17, 2017: Inorganic Chemistry
Vincent André, Vincent Dalibard, Emmanuelle Dernis, Stéphane Varin, Grégoire Cormier
Radioisotope synovectomy has been extensively used to treat patients with chronic inflammatory joint disease but has moved to a less prominent position since the introduction of new and highly effective drugs. Remaining indications are refractory synovitis, pigmented villonodular synovitis as an adjunct to surgery, and hemophilic arthropathy. The three main radioisotopes used are yttrium-90, rhenium-186, and erbium-189. Radioisotope synovectomy should be performed only by highly experienced professionals, to minimize the risk of injection-related complications...
June 23, 2017: Joint, Bone, Spine: Revue du Rhumatisme
Igor O Koshevoy, Kristina S Kisel, Alexei S Melnikov, Elena V Grachova, Pipsa Hirva, Sergey P Tunik
The bifunctional aminopyridine ligands H2N-(CH2)n-4-C5H4N (n = 0, L1; 1, L2; 2, L3) have been utilized for the preparation of rhenium complexes [Re(phen)(CO)3(L1-L3)]+ (1-3). 2 and 3 with NH2-coordinated L2/L3 were coupled with cycloplatinated motifs {Pt(ppy)Cl} and {Pt(dpyb)}+ to give the bimetallic species [Re(phen)(CO)3(μ-L2/L3)Pt(ppy)Cl]+ (4, 6) and [Re(phen)(CO)3(μ-L2/L3)Pt(dpyb)]2+ (5, 7). In solution, complexes 4 and 6 show 3MLCT {Re}-based emission at 298 K, which changes the parentage to 3IL(ppy) state at 77 K...
June 21, 2017: Chemistry: a European Journal
Karina P Morelli Frin, Rafael M de Almeida
Mono-nuclear fac-[Re(CO)3(ph2phen)(4,4'-bpy)](+) and di-nuclear [(ph2phen)(CO)3Re(4,4'-bpy)Re(ph2phen)(CO)3](2+) complexes, ph2phen = 4,7-diphenyl-1,10-phenanthroline and 4,4'-bpy = 4,4'-bipyridine, were synthesized and characterized by (1)H NMR, UV-visible and FT-IR spectroscopy. Also, their photophysical properties were investigated using steady-state and time-resolved emission spectroscopy. Both complexes showed UV absorption assigned to intraligand, (1)ILph2phen, and metal-to-ligand charge transfer, (1)MLCTRe→ph2phen, transitions, and typical (3)MLCTRe→ph2phen emission (ϕ = 0...
June 14, 2017: Photochemical & Photobiological Sciences
Masayuki Naruto, Santosh Agrawal, Katsuaki Toda, Susumu Saito
Carboxylic acids (CAs) are one of the most ubiquitous and important chemical feedstocks available from biorenewable resources, CO2, and the petrochemical industry. Unfortunately, chemoselective catalytic transformations of CH n CO2H (n = 1-3) groups into other functionalities remain a significant challenge. Herein, we report rhenium(V) complexes as extremely effective precatalysts for this purpose. Compared to previously reported heterogeneous and homogeneous catalysts derived from high- or low-valent metals, the present method involves a α-C-H bond functionalization, a hydrogenation, and a hydrogenolysis, which affords functionalized alcohols with a wide substrate scope and high chemoselectivity under relatively mild reaction conditions...
June 13, 2017: Scientific Reports
Lucas Prieto, Jeremie Rossier, Katarzyna Derszniak, Jakub Dybas, René M Oetterli, Emmanuel Kottelat, Stefan Chlopicki, Felix Zelder, Fabio Zobi
This communication describes the anti-platelet effects of a new class of cis-rhenium(ii)-dicarbonyl-vitamin B12 complexes (B12-ReCORMs) with tuneable CO releasing properties.
June 22, 2017: Chemical Communications: Chem Comm
Gisela D Hess, Tobias Fiedler, Frank Hampel, John A Gladysz
Reactions of Re(CO)5(X) (X = Cl, Br) or [Re2(CO)4(NO)2(μ-Cl)2(Cl)2] and the phosphines P((CH2)mCH═CH2)3 (m = 6, a; 7, b; 8, c) give mer,trans-Re(CO)3(X)(P((CH2)mCH═CH2)3)2 (53-95%) or cis,trans-Re(CO) (NO) (Cl)2(P((CH2)6CH═CH2)3)2 (57%), respectively. Additions of Grubbs' catalyst (5-10 mol %, 0.0010-0.0012 M) and subsequent hydrogenations (PtO2, ≤5 bar) yield the gyroscope-like complexes mer,trans-R e(CO)3(X)(P((CH2)n)3 P) (n = 2m + 2; X = Cl, 7a,c; Br, 8a,c; 18-61%) or cis,trans-R e(CO)(NO)(Cl)2(P((CH2)14)3 P) (14%), respectively, and/or the isomers mer,trans-R e(CO)3(X)( P(CH2)n-1 CH2)((CH2)n)( P(CH2)n-1 CH2) (X = Cl, 7'a-c; Br, 8'b; 6-27%)...
June 9, 2017: Inorganic Chemistry
Rebeca Arévalo, Christopher M Vogels, Gregory A MacNeil, Lucía Riera, Julio Pérez, Stephen A Westcott
The first examples for the rhenium-catalysed hydroboration of aldehydes, ketones and aldimines, including heteroaromatic quinoline, are reported herein. Reactions are remarkably chemoselective and tolerant of several functional groups. A wide array of rhenium complexes were efficient pre-catalysts for these hydroborations, including new low-valent complexes of the formula [Re(N-N)(CO)3(L)]X (N-N = bipy derivative, L = labile ligand/solvent, and X = [BAr(F)4](-) and [B(3,5-di-tBu-cat)2](-)), which have been characterized fully including an X-ray diffraction study for [Re(bipy)(CO)3(quin)][BAr(F)4] (2)...
June 7, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
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