Search results for "SSB"
showing 10 items of 537 documents
Synthesis and characterization of trbenzyltin(IV) and dibenzyltin(IV) complexes of 2-((2Z)-3-hydroxy-1-methyl-2-butenylidene)amino)acetic acid: Cryst…
2007
Reactions of equimolar quantities of potassium 2-{[(2Z)-3-hydroxy-1-methyl-2-butenylidene]amino}acetate, with R n SnX4−n (R: benzyl– and n=2 or 3) in methanol yielded products of compositions LHSn(PhCH2)3 and LSn(PhCH2)2, respectively. The complexes were characterized by microanalysis, IR, NMR (1H, 13C, 119Sn) and 119mSn Mossbauer spectroscopy. A full characterization of the structure of the complex, tribenzyl{2-{[(2Z)-3-hydroxy-1-methyl-2-butenylidene]amino}acetato}tin(IV), was carried out by single crystal X-ray crystallography. The compound exists as centrosymmetric dimers in which two ligand molecules bridge the two tin centres. Each of the tin atoms in the dimeric unit is five coordina…
Predictive Capacity of Boar Sperm Morphometry and Morphometric Sub-Populations on Reproductive Success after Artificial Insemination
2021
The aim of the study was to compare the morphometric features of sperm head sizeand shape from the Pietrain line and the Duroc×Pietrain boar crossbred terminal lines, and toevaluate their relationship with reproductive success after artificial insemination of sows producedfrom crossbreeding the York, Landrace and Pietrain breeds. Semen samples were collected from 11sexually mature boars. Only ejaculates with greater than 70% motility rate and <15% of abnormalsperm were used for artificial inseminations (AI) and included in the study. Samples were analyzedusing an ISAS®v1 computer-assisted sperm analysis system for eight morphometric parameters ofhead shape and size (CASA-Morph). Sub-populat…
The oxidation state of iron in silicic melt at 500 MPa water pressure
2002
Abstract The dependence of the ferric–ferrous ratio in silicate melts on oxygen fugacity was studied in the system SiO2(Qz)–NaAlSi3O8(Ab)–CaAl2Si2O8(An)–H2O using Mossbauer spectroscopy. Experiments were performed under water-saturated conditions at 500 MPa, and at temperatures of 850 and 950 °C, covering a range typical for magmatic processes. The oxygen fugacity was varied in the fO2 range from Cu–Cu2O buffer to slightly more reducing conditions than the wustite–magnetite buffer. The iron redox ratio was determined by analyzing the Mossbauer parameter distribution that was modeled based on experimental spectra collected at room temperature on the quenched samples. The obtained iron redox …
Noves interpretacions d'Antígona en la filosofia del XX
2001
Partiendo de la obra de I. Berlin y del pluralismo de los valores, se presentan dos interpretaciones de la figura de 'Antígona' desde las obras de dos mujeres filósofas del s. XX, M. Nussbaum y M. Zambrano, la cual no sólo comentó el drama de Sófocles, sino que desde la vivencia del drama de la guerra civil española compuso su propia versión de este personaje imperecedero.
Hexanuclear iron(III) salicylaldoximato complexes presenting the [Fe6(mu3-O)2(mu2-OR)2]12+ core: syntheses, crystal structures, and spectroscopic and…
2006
The use of salicylaldehyde oxime (H2salox) in iron(III) carboxylate chemistry has yielded two new hexanuclear compounds [Fe6(mu3-O)2(O2CPh)10(salox)2(L)2].xMeCN.yH2O [L = MeCONH2, x = 6, y = 0 (1); L = H2O, x = 2, y = 3 (2)]. Compound 1 crystallizes in the triclinic space group P with (at 25 degrees C) a = 13.210(8) A, b = 13.87(1) A, c = 17.04(1) A, alpha = 105.79(2) degrees , beta = 96.72(2) degrees , gamma = 116.69(2) degrees , V = 2578.17(2) A(3), and Z = 1. Compound 2 crystallizes in the monoclinic space group C2/c with (at 25 degrees C) a = 21.81(1) A, b = 17.93(1) A, c = 27.72(1) A, beta = 111.70(2) degrees , V = 10070(10) A(3), and Z = 4. Complexes 1 and 2 contain the [Fe6(mu3-O)2(m…
Phase separated Cu@Fe3O4 heterodimer nanoparticles from organometallic reactants
2011
Cu@Fe3O4 heteroparticles with distinct morphologies were synthesized from organometallic reactants. The shape of the magnetic domains could be controlled by the solvent and reaction conditions. They display magnetic and optical properties that are useful for simultaneous magnetic and optical detection. After functionalization, the Cu@Fe3O4 heterodimers become water soluble. The morphology, structure, magnetic and optical properties of the as-synthesized heterodimer nanoparticles were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), mossbauer spectroscopy, superconducting quantum interference device (SQUID) magnetometry, and dark field imaging. A special a…
Complexes of organometallic compounds
1974
Abstract Novel 1/1 adducts have been obtained from the complex N , N ′-ethylenebis(salicylideneiminato)nickel(II) (NiSalen) with di- and mono-organotin(IV) chlorides, and their solid state configuration investigated by Mossbauer , IR and electronic spectroscopy and magnetic measurements. In coordinated NiSalen the square planar structure is maintained around Ni II , and the coordination to tin involves three-coordinate phenolic oxygens. The environment of Sn IV is judged to be octahedral in both types of compounds. A trans -R 2 , cis -Cl 2 configuration is advanced for R 2 SnCl 2 NiSalen.
Multiple spin phases in a switchable Fe(ii) complex: polymorphism and symmetry breaking effects
2018
Polymorphism in spin-crossover (SCO) compounds allows accessing additional forms of switchable materials with diverse transition properties. We have prepared three polymorphs of a new complex [FeLBr(dca)2], where LBr is N,N′-bis[(5-bromo-2-pyridyl)methyl]ethane-1,2-diamine and dca is dicyanamide. They display different SCO properties: the α-form displays a hysteretic one-step switch centered at 134 K, the β-form undergoes hysteretic two-step spin transition with a plateau (T1/2 = 153 and 144 K) and the γ-form remains high spin (HS) over the whole temperature region. The kinetic origin of the hysteresis loop was demonstrated in temperature rate dependent magnetic measurements. Spin transitio…
Hybrid materials containing organometallic cations and 3-D anionic metal dicyanamide networks of type [Cp*2M][M′(dca)3]
2004
A new series of hybrid materials of type [Cp*2M][M′(dca)3] has been prepared by cation templation and structurally characterised (M = Fe(III), Co(III); M′ = Mn(II), Fe(II), Co(II), Ni(II), Cd(II); dca− = N(CN)2−). The crystallographic analysis of [Cp*2Fe][Cd(dca)3] showed that the [Cd(dca)3]− anionic framework is of a symmetrical 3-D α-polonium type, containing octahedral Cd nodes and μ1,5-dca bridging ligands. The [Cp*2Fe]+ cations occupy the cube-like cavities within the framework. The cationic and anionic-framework sublattices remain magnetically independent and display susceptibilities, over the range 300 to 2 K, of a Curie–Weiss nature obtained by adding a S = 1/2 (Cp*2Fe+) or a S = 0 …
Stimuli responsive hybrid magnets : tuning the photoinduced spin-crossover in Fe(III) complexes inserted into layered magnets
2013
The insertion of a [Fe(sal_2 trien)]^+ complex cation into a 2D oxalate network in the presence of different solvents results in a family of hybrid magnets with coexistence of magnetic ordering and photoinduced spin crossover (LIESST effect) in compounds [Fe^{III}(sal_2 trien)][Mn^{II}Cr^{III}(ox)_3]·CHCl_3 (1·CHCl_{3}) [Fe^{III}(sal_{2} trien)][Mn^{II}Cr^{III}(ox)_{3}]·CHBr_{3} (1·CHBr_{3}) and [Fe^{III}(sal_{2} trien)][Mn^{II}Cr^{III}(ox)_{3}]·CH_{2}Br_{2} (1·CH_{2}Br_{2}). The three compounds crystallize in a 2D honeycomb anionic layer formed by Mn^{II} and Cr^{III} ions linked through oxalate ligands and a layer of [Fe(sal_{2} trien)]^{+} complexes and solvent molecules (CHCl_{3} CHBr_{…