205 research outputs found
Coordination chemistry of 2-pyrimidinolate: Synthesis and characterization of a neutral tetrameric rhodium(I) derivative
No full textA novel metal-organic complex of analytical Rh(COD)(2-pymo) formulation (COD = 1,5-cyclooctadiene, 2-Hpymo = 2-hydroxypyrimidine) has been prepared by reacting [Rh(COD)Cl]2 with 2-Hpymo. While direct syntheses in a variety of solvents (acetone, toluene or methanol) typically afforded amorphous powders, recrystallization from methanol allowed to perform a single crystal data collection on the CH3OH solvate. The crystal structure of the latter [tetragonal, P-42c, a = 13.9780(2), c = 14.4980(10) Å, V = 2832.7(6) Å^3] contains cyclic [Rh(COD)(2-pymo)]4 tetramers, in which distorted square planar metal atoms are bridged by n1-μ2-N,N′-exo-bidentate 2-pymo ligands in 1,3-alternate disposition. Upon dissolving both the amorphous and the crystalline (solvated) species in CD2Cl2, variable temperature NMR spectra confirmed the presence of identical (tetrameric) species, thus excluding the existence of other oligomers of different nuclearity in the amorphous powders
SYNTHESIS, A. MASPERO, INCLUDING AN AB-INITIO XRPD STUDY OF CUDMNPZ HDMNPZ, -DIMETHYL--NITRO PIRAZOLE.
No full textHomme libre – Homme livre: François Maspero
No full textThe blog post "Homme libre – Homme livre: François Maspero" explores the life and works of François Maspero, a notable French editor and writer. The author discusses the serendipitous timing of receiving a book about Maspero and learning of his death. The book, "François Maspero et les paysages humains," is described as a detailed tribute, covering Maspero\u27s literary contributions and personal experiences, including his time in Algeria. The post emphasizes the book\u27s value as a collection of testimonies and documents, providing insights into Maspero\u27s life, his publishing endeavors, and his influence on French intellectual and political scenes. The author also mentions Maspero\u27s role as a geographer, highlighting how his writings offer a unique perspective on human landscapes. Additionally, the post notes the limited recognition of Maspero in Germany and underscores the significance of his work in amplifying the voices of dissident movements in Eastern Europe during the 1970s.
Le billet de blog "Homme libre – Homme livre : François Maspero" explore la vie et les œuvres de François Maspero, un éditeur et écrivain français renommé. L\u27auteur évoque la coïncidence troublante entre la réception d\u27un livre sur Maspero et l\u27annonce de son décès. Le livre, "François Maspero et les paysages humains," est décrit comme un hommage exhaustif, détaillant les contributions littéraires de Maspero et ses expériences personnelles, y compris son séjour en Algérie. Le billet met en avant la valeur de cet ouvrage en tant que recueil de témoignages et de documents, offrant un aperçu de la vie de Maspero, de sa maison d\u27édition et de son influence sur les paysages intellectuels et politiques français. L\u27auteur souligne également le rôle de Maspero en tant que géographe, montrant comment ses écrits offrent une perspective unique sur les paysages humains. En outre, le billet note la reconnaissance limitée de Maspero en Allemagne et insiste sur l\u27importance de son travail dans l\u27amplification des voix des mouvements dissidents en Europe de l\u27Est durant les années 1970
Elucidating the CO2 adsorption mechanisms in the triangular channels of the bis(pyrazolate) MOF Fe2(BPEB)3 by in situ synchrotron X-ray diffraction and molecular dynamics simulations
No full textThe structural origin of the remarkable performance of the metal–organic framework Fe2(BPEB)3 as a CO2 adsorbent (40.5% of the host weight at 298 K and 10 bar) was investigated by combining advanced experimental and computational tools.</p
Synthesis, structure and thermal behaviour of two magnesium complexescontaining the 1,4-bis(5-tetrazolyl)benzene ligand
No full textSynthesis of alkaline-earth hexaborides, MB6 (M = Ca, Ba, Sr), by a solid state metathesis (SSM) reaction
No full textA new synthetic pathway for alkaline-earth hexaborides has been developed. This method involves a solid state metathesis between an alkaline-earth (Ca, Ba, Sr) salt and MgB2, which can be performed at relatively low temperatures, without any catalyst and with no hazardous side products. The proposed protocol shows a good reproducibility and a much lower energy consumption (and, consequently, lower costs) than any known traditional synthesis. In view of the possibility of using alkaline-earth hexaborides as overdopants in MgB2 superconductors in order to enhance its transport properties in magnetic field, several MgB2 + MB6 bulk composites were obtained with the “Reactive Liquid Mg Infiltration” (Mg-RLI) technique, and characterized by X-ray Powder Diffraction (XRPD) and Scanning Electron Microscopy (SEM) methods
Cu(II) bifunctional (N,O,Oâ2) coordination polymer: A case study for complex ab-initio crystal structure determination from PXRD data
No full textThe synthesis of a novel Cu(II) bifunctional (N,O,Oâ2) coordination polymer, the Cu(PzHP) compound, has been carried out by coupling Cu(II) salts and the newely synthesized H2(PzHP) organic linker (H2(PzHP) = 1-[4-(1H) -pyrazolyl]-2-methyl-3-hydroxy-4(1H)-pyridinone). Despite to the numerous attempts done for the growth of suitable single crystals and to the synthetic trials carried out to ameliorate the crystallinity of the Cu(PzHP) coordination polymer, its diffraction pattern was always characterized by a discouraging, less-than-ideal, crystallinity. Notwithstanding the extended disorder, leading to a higher than required space group symmetry, we succeeded in the description of its relevant structural features by following an unconventional route to ab-initio structure solution. In this process consideration on the coordination ability of the ligand and on the space group symmetry have been taken into account to âmanuallyâ achieve the initial structural model, highlighting that, in some cases, it is still possible to ascertain by PXRD the crystal structure of a material that shows challenging, broad, PXRD pattern
Ab-initio XRPD structural characterization of coordination polymers: The case of [Ag(C3H3N2CS2)]
No full textThe crystal structure of the one-dimensional polymer [Ag(C3H3N2CS2)] has been determined from conventional X-ray powder diffraction methods, through simulated annealing and Rietveld refinement techniques [Ag(C3H3N2CS2)] is monoclinic, P21/c; a = 8.409(1), b = 11.740(1), c = 6.721(1) Å, β = 101.86(2)°, V = 649.3(2) Å^3; Z = 4; ρ = 2.566 g cm^-3. Final Rwp, Rp and RF agreement factors, for 3100 data points collected in the 8-70° 2θ range, are 0.091, 0.071 and 0.058, respectively. Anisotropic peak shapes and high-angle tails for the 0k0 (and neighboring) reflections suggest that the polymeric chains, aligned along b, suffer from a partial disorder, in that packing of adjacent molecules does not conform to a rigorous crystalline, truly periodic, tiling
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