- Chlorination of manganese oxides
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In this work the reaction between several manganese oxides and chlorine is investigated. The reaction path for the chlorination of the oxides is established, which involves recrystallization of high valence manganese oxides: Mn3O4 an
- Fouga, Gastón G.,De Micco, Georgina,Bohé, Ana E.
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- MASS-SPECTROMETRIC MEASUREMENTS OF THERMODYNAMIC PROPERTIES OF THE MOLTEN KCl-MnCl2 SYSTEM.
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Activities and heats of mixing for the molten KCl-MnCl//2 system were determined mass-spectrometrically by the ion-current ratio method. Activities of components KCl and MnCl//2 show large negative deviations from Raoult's law, indicating a very strong interaction between KCl and MnCl//2. Entropies of mixing calculated from measured activities and heats of mixing have minimum values in the vicinity of 33% MnCl//2, and have been compared with those calculated on the basis of some molten structure models to infer possible chemical species in the molten salt.
- Sasamoto,Itoh,Sata
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- Formation of super disperse phase and its influence on equilibrium and thermodynamics of thermal dehydration
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New data on the dehydration and rehydration processes of calcium, manganese and copper dichlorides are presented that reveal surprising, in a certain sense, behaviour difficult to be explained for the last two chlorides in terms of the usual conception of thermodynamic equilibrium. A substantial role of a super disperse phase at studying the equilibrium of the thermal decomposition of a hydrate is postulated to explain the experimental results for manganese and copper dichlorides. It is shown that the formation of such a phase of the hydrate is able to change appreciably the experimental results, causing the increase of water vapour pressure and the decrease of the derived enthalpy of a reaction. The results obtained allow to understand the reasons for considerable differences of some literature data. They enable to receive more precise and reliable data for thermal dehydration and probably for some other decomposition processes.
- Polyachenok,Dudkina,Branovitskaya,Polyachenok
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- Study on coordination behaviour of manganese chloride with L-α-histidine
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The reaction thermodynamic and kinetic equations for the non-reversible reactions are established. The enthalpy change of formation reaction of manganese(II) histidine (His) complex in water has been determined by microcalorimetry, using manganese chlorid
- Shengli,Sanping,Huanyong,Rongzu,Qizhen
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- Coordination chemistry in the solid state: Reactivity of manganese and cadmium chlorides with imidazole and pyrazole and their hydrochlorides
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Crystalline coordination compounds [MnCl2(Hpz)2] 3, [CdCl2(Hpz)2] 5, [MnCl2(Him)2] 9, and [CdCl2(Him)2] 13 (Him = imidazole; Hpz = pyrazole) can be synthesized in solid state reactions by grinding together the appropriate metal chloride and 2 equiv of the neutral ligand. Similarly, grinding together the metal chlorides with the ligand hydrochloride salts produces the halometallate salts [H2pz][MnCl3(OH2)] 1, [H2pz][CdCl4] 4, [H2im]6[MnCl 6][MnCl4] 8, and [H2im]6[CdCl 6][CdCl4] 11. In contrast, reacting the metal chloride salt with the ligand in concentrated HCl solution yields a second set of salts [H2pz][MnCl3] 2, [H2im][MnCl 3(OH2)2] 7, and [H2im][CdCl 3(OH2)]·H2O 12. Compound 5 can be partly dehydrochlorinated by grinding with KOH to form an impure sample of the pyrazolate compound [Cd(pz)2] 6, while recrystallizing 9 from ethanol yielded crystals of solvated [Mn4Cl8(Him)8] 10. The crystal structure determinations of 1, 2, 4, 11, and 12 are reported.
- Adams, Christopher J.,Kurawa, Mukhtar A.,Orpen, A. Guy
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- Pyridine-type complexes of transition-metal halides. Part XV. Mn(II) chloride complexes with 3,4- and 3,5-lutidine
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Manganese(II) chloride complexes with 3,4- and 3,5-lutidine have been prepared. The crystal symmetry and cell dimensions have been calculated on the basis of powder diffraction data. The compounds were characterised also by FT-IR spectrometry. The thermal
- Szecsenyi, K. Mészáros,Wadsten,Kovács,Liptay
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- Evolution from discrete mononuclear complexes to trinuclear linear cluster and 2D coordination polymers of Mn(II) with dihydrazone Schiff bases: Preparation, structure and thermal behavior
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Four Mn(II) coordination compounds based on the 2,6-diacetylpyridine bis(isonicotinoylhydrazone) (H2L1) and 2,6-diacetylpyridine bis(nicotinoylhydrazone) (H2L2), were prepared using different synthetic condition
- Bourosh, Paulina N.,Bulhac, Ion,Ch. Kravtsov, Victor,Cocu, Maria,Croitor, Lilia,Danilescu, Olga,Petuhov, Oleg
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- Microcalorimetry study of the reactivity of two manganese ammonia chlorides
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The reaction [Mn(NH3)2]Cl2 + 4NH3 [Mn(NH3)6]Cl2, which is of potential use in chemical heat pumps, was studied by means of differential scanning calorimetry. The thermodynamic c
- Marty A.
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- Enhanced Stability of the FeII/MnII State in a Synthetic Model of Heterobimetallic Cofactor Assembly
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Heterobimetallic Mn/Fe cofactors are found in the R2 subunit of class Ic ribonucleotide reductases (R2c) and R2-like ligand binding oxidases (R2lox). Selective cofactor assembly is due at least in part to the thermodynamics of MII binding to the apoprotein. We report here equilibrium studies of FeII/MnII discrimination in the biomimetic model system H5(F-HXTA) (5-fluoro-2-hydroxy-1,3-xylene-α,α′-diamine-N,N,N′,N′-tetraacetic acid). The homobimetallic F-HXTA complexes [Fe(H2O)6][1]2·14H2O and [Mn(H2O)6][2]2·14H2O (1 = [FeII2(F-HXTA)(H2O)4]-; 2 = [MnII2(F-HXTA)(H2O)4]-) were characterized by single crystal X-ray diffraction. NMR data show that 1 retains its structure in solution (2 is NMR silent). Metal exchange is facile, and the heterobimetallic complex [FeIIMnII(F-HXTA)(H2O)4]- (3) is formed from mixtures of 1 and 2. 19F NMR was used to quantify 1 and 3 in the presence of excess MII(aq) at various metal ratios, and equilibrium constants for FeII/MnII discrimination were calculated from these data. FeII is preferred over MnII with K1 = 182 ± 13 for complete replacement (2 21). This relatively modest preference is attributed to a hard-soft acid-base mismatch between the divalent cations and the polycarboxylate ligand. The stepwise constants for replacement are K2 = 20.1 ± 1.3 (2 23) and K3 = 9.1 ± 1.1 (3 21). K2 > K3 demonstrates enhanced stability of the heterobimetallic state beyond what is expected for simple MnII FeII replacement. The relevance to FeII/MnII discrimination in R2c and R2lox proteins is discussed.
- Kerber, William D.,Goheen, Joshua T.,Perez, Kaitlyn A.,Siegler, Maxime A.
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- Infrared spectra of CX3-MnX and CX2=MnX2 (X = H, F, Cl) prepared in reactions of laser-ablated manganese atoms with halomethanes
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Small manganese insertion (CX3-MnX) and methylidene (CX 2=MnX2) complexes, carrying the highest multiplicities (sextet and quartet) among the analogous group 3-12 metal complexes, are produced in laser-ablated Mn atom reactions with halomethanes and identified in matrix infrared spectra with isotopic shifts and DFT frequency calculations. The linear C-M-X structure of the Mn insertion complexes resembles that of Grignard reagent molecules unlike those of other transition-metal analogues except Fe, and the Mn-C bond bears high s character, on the basis of DFT calculations. The Mn methylidenes have planar structures, common among early transition-metal analogues, revealing that Mn has borderline properties between the early and late transition metals. The computed C-Mn bond lengths of the carbene complexes in the quartet states (1.855-1.872 A) are considerably shorter than those of the insertion complexes in the sextet states (2.057-2.120 A), which is likely due to the one-half π-bond order and large ionic contribution to bonding in the carbene complexes. The tendency of increasing preference for higher oxidation-state products on going down in a family group is most dramatic among the group 7 metals Mn and Re.
- Cho, Han-Gook,Andrews, Lester
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- Stereospecific Stille Cross-Couplings Using Mn(II)Cl2
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Cross-coupling reactions are a staple in organic synthesis, especially for C-C bond formation with sp- and sp2-carbon electrophiles. In recent years, the range of accessible C-C bonds has been extended to stereogenic centers which expedites access to greater molecular complexity. However, these reactions predominantly depend upon late transition metal (LTM) catalysts whose cost, toxicity, and/or environmental impact have come under increasing scrutiny and governmental regulation. Here, we report Mn(II)Cl2 complexes alone, or with assistance from copper, catalyze the stereospecific cross-coupling of α-alkoxyalkylstannanes with organic electrophiles with complete retention of configuration.
- Dakarapu, Rambabu,Falck, John R.
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p. 1241 - 1251
(2018/02/09)
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- New complexes of 4-[(4-fluorophenyl)amino]-4-oxobut-2-enoic acid with selected transition metal ions: Synthesis, thermal, and magnetic properties
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Complexes of 4-[(4-fluorophenyl)amino]-4-oxobut-2-enoic acid, HL, with Mn(II), Co(II), Ni(II), Cu(II), Nd(III), Gd(III), and Er(III) were synthesized and characterized by various physico-chemical methods: elemental analysis, FT-IR, TG, DTG, DSC, TG/FT-IR, XRF, XRD, and magnetic measurements using the Gouy’s method and a SQUID-VSM magnetometer. The complexes were found to be hydrates (except Er(III) complex) containing 1 to 4 molecules of water. The carboxylate groups acted as bidentate ligands.
- Ferenc,Sadowski,Tarasiuk,Cristóv?o,Osypiuk,Sarzyński
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p. 2719 - 2727
(2017/12/26)
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- Benzyl alcohol-based synthesis of oxide nanoparticles: The perspective of SN1 reaction mechanism
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In this paper, we describe a class of benzyl alcohol-based reactions for the synthesis of a series of inorganic oxide nanoparticles. Benzyl alcohol served as both the solvent and the reagent to interact with various metal chlorides for the synthesis of a series of metal oxides and compound oxides. Typical metal(iv) oxides, like TiO2, metal(iii) oxides, like Fe 2O3, and metal(ii) oxides, like ZnO, with uniform size and special dispersibility, have been prepared through these reactions. The reaction can be illustrated from the perspective of SN1 reaction mechanism attributed to the easier formation of benzyl carbocation and unique reactivity of benzyloxy group with nucleophilic agents. By adjusting the experimental conditions, it was found that this type of reaction is available for the synthesis of many inorganic oxides. The Royal Society of Chemistry 2013.
- Hu, Mingjun,Xu, Jiaju,Gao, Jiefeng,Yang, Shiliu,Wong, Julia Shuk Ping,Li, Robert K. Y.
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p. 9777 - 9784
(2013/08/23)
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- Microwave-assisted carbohydrohalogenation of first-row transition-metal oxides (M = V, Cr, Mn, Fe, Co, Ni, Cu) with the formation of element halides
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The anhydrous forms of first-row transition-metal chlorides and bromides ranging from vanadium to copper were synthesized in a one-step reaction using the relatively inexpensive element oxides, carbon sources, and halogen halides as starting materials. The reactions were carried out in a microwave oven to give quantitative yields within short reaction times.
- Berger, Matthias,Neumeyer, Felix,Auner, Norbert
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supporting information
p. 11691 - 11693
(2013/11/19)
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- A mitochondria-targeted macrocyclic Mn(II) superoxide dismutase mimetic
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Superoxide (O2s-) is the proximal mitochondrial reactive oxygen species underlying pathology and redox signaling. This central role prioritizes development of a mitochondria-targeted reagent selective for controlling O2s-. We have conjugated a mitochondria-targeting triphenylphosphonium (TPP) cation to a O2 s--selective pentaaza macrocyclic Mn(II) superoxide dismutase (SOD) mimetic to make MitoSOD, a mitochondria-targeted SOD mimetic. MitoSOD showed rapid and extensive membrane potential-dependent uptake into mitochondria without loss of Mn and retained SOD activity. Pulse radiolysis measurements confirmed that MitoSOD was a very effective catalytic SOD mimetic. MitoSOD also catalyzes the ascorbate-dependent reduction of O2s-. The combination of mitochondrial uptake and O2s- scavenging by MitoSOD decreased inactivation of the matrix enzyme aconitase caused by O2s-. MitoSOD is an effective mitochondria-targeted macrocyclic SOD mimetic that selectively protects mitochondria from O2s- damage.
- Kelso, Geoffrey F.,Smith, Robin A. J.,Maroz, Andrej,Anderson, Robert F.,Cocheme, Helena M.,Logan, Angela,Prime, Tracy A.,James, Andrew M.,Ross, Meredith F.,Murphy, Michael P.,Peskin, Alexander V.,Winterbourn, Christine C.,Brooker, Sally,Porteous, Carolyn M.
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p. 1237 - 1246,10
(2020/08/24)
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- Influence of manganese on magnetic and electronic properties of ZnCr 2Se4
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The Zn1-xMnxCr2Se4 crystals were prepared by chemical vapor transport in closed silica tubes using ZnSe and MnSe with CrCl3 as the transport agent. Four crystals with different Mn content (x = 0.12, 0.13, 0.18 and 0.24) were studied by X-ray photoelectron spectroscopy (XPS) and magnetic measurements in order to determine influence of manganese on their magnetic and electronic properties. The XPS revealed no change of chemical shifts of Cr core lines indicating a Cr3+ (3d 3) electronic configuration. Magnetization measurements revealed a systematic increase in saturation magnetic moments from 6.32 μB/mol for x = 0.12 to 7.63 μB/mol for x = 0.24, as well as effective paramagnetic Bohr magneton numbers from 4.87 μB/mol for x = 0.12 to 6.91 μB/mol for x = 0.24.
- Jendrzejewska, Izabela,Zajdel, Pawe?,Heimann, Jan,Krok-Kowalski, Józef,Mydlarz, Tadeusz,Mrzigod, Janusz
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p. 1881 - 1886
(2012/08/14)
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- Kinetic study of Hubnerite (MnWO4) chlorination
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The kinetics of Argentinean Hubnerite (MnWO4) chlorination using gaseous chlorine as chlorination agent was studied between 750 and 950 °C. The relative mass change during the chlorination reaction was continuously monitored using a high resolution thermogravimetric system. The starting temperature for the reaction of the manganese tungstate with chlorine was determined at about 650°C. The influence of gaseous flow rate, sample mass, chlorine partial pressure, and temperature on the reaction rate was analyzed. The dependence of the reaction rate with sample mass clearly indicates that the reaction is not occurring under chemical control, so the reaction proceeds under mixed control for sample masses greater than 0.5 mg. In those conditions, an apparent activation energy of 198 ± 9 kJ mol-1 was obtained with an isoconversional method. Concerning the influence of chlorine partial pressure, it was determined that pressures greater than 35 kPa do not modify the kinetic regime. For the experiment at 850°C, it was found that the chlorination rate was proportional to a potential function of the partial pressure of chlorine whose exponent is around 0.85. Finally, a global rate equation that includes these parameters was developed.
- Fouga,Taddeo,Bosco,Bohé
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- Thermal analysis of manganese (II) complexes of general formula (Et 4N)2[MnBrnCl4?n]
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Thermal decomposition of compounds consisting of tetrahalogenomanganates(II) anions, [MnBrnCl4?n] 2? (n = 0-4), and a tetraethylammonium cation has been studied using the DSC and TG techniques. The measurements were carried out in an argon atmosphere over the temperature ranges 173-500K (DSC) and 300-1073K (TG). Products of the thermal decomposition were identified by MS, FTIR, Far-FTIR spectroscopy as well as X-ray powder diffractometry.
- Styczeń,Gazda,Wyrzykowski
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- ANTIOXIDANT FOR PREVENTING AND TREATING DISEASES CAUSED BY OXIDATIVE STRESS
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The invention relates to the pharmaceutical industry and to medicine, in particular to a novel highly active antioxidant which is used for preventing and treating diseases caused by oxidative stress and scarcity of oxygen in an organism and which is embodied in the form of a complex of a metal cation selected form an iron, copper, zinc and manganese group with ratio and cevitamic acid and/or dihydrocevitamic acid of general formula (I): emRu(AA)r(DGAA)pXn.(I). A method for producing a granulate containing said complex and the tableted and encapsulated form based thereon are also disclosed.
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- Antioxidants for preventing and treating diseases caused by oxidative stress
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Antioxidant compositions for the treatment and prophylaxis of illnesses associated with oxidative stress and lack of oxygen in the human body, comprising a complex of a metal selected from the group consisting of iron, copper, zinc and manganese with rutin and ascorbic acid and/or dihydroascorbic acid. Methods for synthesizing the antioxidant compositions and granulates, tablets and capsules containing antioxidant compositions are also provided.
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- Reinvestigation of arylmanganese chemistry - Synthesis and molecular structures of [(thf)4Mg(μ-Cl)2Mn(Br)Mes], [Mes(thf)Mn(μ-Mes)]2, and (MnPh2)∞ (Ph = C6H5; Mes = mesityl, 2,4,6-Me3C6H2)
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The reaction of 2,4,6-trimethylphenylmagnesium bromide (MesMgBr) with manganese(II) chloride in an equimolar ratio yields [(thf)4Mg(μ-Cl)2Mn(Br)Mes] (1) with two bridging chloro ligands and a Mn-C bond length of 2.136(5) A??. A molar ratio of 2:1 leads to a metathesis reaction and the formation of [Mes(thf)Mn(μ-Mes)]2 (2) with two bridging mesityl groups. Whereas THF-free [MnMes2]3 crystallizes as a trimer from toluene solution, the reduced bulkiness of the phenyl groups in (MnPh2)∞ (3) leads to the formation of a chain-like structure with Mn-C bond lengths of 2.245(3) A??.
- Fischer, Reinald,G?rls, Helmar,Friedrich, Manfred,Westerhausen, Matthias
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p. 1107 - 1111
(2009/07/26)
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- Indirect, reversible high-density hydrogen storage in compact metal ammine salts
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The indirect hydrogen storage capabilities of Mg(NH3) 6Cl2, Ca(NH3)8Cl2, Mn(NH3)6Cl2, and Ni(NH3) 6Cl2 are investigated. All four metal ammine chlorides can be compacted to solid tablets with densities of at least 95% of the crystal density. This gives very high indirect hydrogen densities both gravimetrically and volumetrically. Upon heating, NH3 is released from the salts, and by employing an appropriate catalyst, H2 can be released corresponding to up to 9.78 wt % H and 0.116 kg H/L for the Ca(NH 3)8Cl2 salt. The NH3 release from all four salts is investigated using temperature-programmed desorption employing different heating rates. The desorption is found mainly to be limited by heat transfer, indicating that the desorption kinetics are extremely fast for all steps. During desorption from solid tablets of Mg(NH3) 6Cl2, Mn(NH3)6Cl2, and Ni(NH3)6Cl2, nanoporous structures develop, which facilitates desorption from the interior of large, compact tablets. Density functional theory calculations reproduce trends in desorption enthalpies for the systems studied, and a mechanism in which individual chains of the ammines are released from the surface of the crystal is proposed to explain the fast absorption/desorption processes.
- Sorensen, Rasmus Z.,Hummelshoj, Jens S.,Klerke, Asbjorn,Reves, Jacob Birke,Vegge, Tejs,Norskov, Jens K.,Christensen, Claus H.
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p. 8660 - 8668
(2009/02/03)
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- On the chemical vapor transport of ternary transition metal- and earth
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The chemical vapor transport of transition metal tungstates MWO4 (M=Mn, Co, Ni, Cu, Zn, Cd) was investigated in dependence on mean transport temperature (923 K to 1223 K) and amount of transport agent Cl2. All tungstates migrate in a temperature gradient ΕT = 100 K from the region of higher temperature to the lower temperature with migration rates of 0.5 to 8 mg/h depending on experimental conditions. The transport behaviour was determined by continuous measurement of mass change during the transport experiments. The results were compared to thermo chemical calculations and the influence of moisture content discussed in detail. MgWO4 migrates under the influence of Cl2 in a temperature gradient 1273 K to 1173 K (migration rate 0.7 mg/h), CaWO4 and SrWO4 in a temperature gradient 1423 K to 1323 K (migration rate 0.1 mg/h).
- Steiner, Udo
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p. 1706 - 1714
(2008/10/09)
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- Ionic aqueous composition containing levomenthol
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A composition for relieving a sensation of respiratory discomfort and/or for promoting natural regeneration of mucous membranes of the nasal cavity. The composition contains levomenthol at a concentration between 10 and 250 mg/l, dissolved in an aqueous ionic solution having an osmolarity at least equal to that of an aqueous solution of sodium chloride at 9 g/l. The aqueous ionic solution is pure sea water, diluted sea water, an aqueous sodium chloride solution, an aqueous sodium chloride solution further containing at least one salt found in sea water, or a mixture thereof.
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- Thermochemistry of the complexes of some microelements and histidine
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Solid complexes of M(His)2Cl2·nH2O (M=Mn, Co, Ni, Cu) of MnCl2·6H2O, CoCl 2·6H2O, NiCl2·6H2O, CuCl2·2H2O and L-α-histidine (His) have been prepared in 95% ethanol solution and characterized by elemental analyses, chemical analyses, IR and TG-DTG. The constant-volume combustion energies of the complexes have been determined by a rotating-bomb calorimeter. The standard enthalpies of formation of the complexes have been calculated as well.
- Chen,Gao,Yang,Hu,Shi
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p. 967 - 975
(2008/10/08)
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- Methods of modulating protein tyrosine kinase function with substituted indolinone compounds
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The invention relates to certain indolinone compounds, their method of synthesis, and a combinatorial library consisting of the indolinone compounds. The invention also relates to methods of modulating the function of protein kinases using indolinone compounds and methods of treating diseases by modulating the function of protein kinases and related signal transduction pathways.
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- Thermal and spectral studies of binary complexes of cyanodithioformate with transition metal ions
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Binary complexes of the type [M(S2CCN)2] (M = Mn2+, Fe2+, Co2+, Ni2+, Cu2+ and Zn2+) have been synthesised from alcoholic solutions. They have been characterised using elemental analyses, IR, UV-VIS spectroscopy, magnetic susceptibility measurement and solution conductance data. In thermogravimetry (TG) studies, all these complexes exhibit a prominent weight loss step between 100 and 330 °C under a N2 atmosphere. Besides, a second weight loss step has also been observed beyond 800° C for the Mn2+, Fe2+ and Co2+ complexes, between 400 and 600 °C for Zn2+ complex and beyond 380 °C for Cu2+ complex. Broad differential thermal analysis (DTA) endotherms are observed corresponding to these weight loss steps. The first weight loss in the TG scan of the complexes follows a deceleratiory α-time curve with D3 mechanism for all complexes. The activation energy (Ea) for the thermal decomposition varies between 43 and 115 kJ/mol and removal of CS2 and/or CS have been suggested. Various decomposition parameters have been calculated.
- Prasad, Rajendra,Kumar, Azad
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- Thermal analysis and vibrational spectroscopy of Mn(II)-urea-halide complexes: Comparative study of the metal-ligand bond strength
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The thermal study of Mn(II)-urea-halide complexes as a function of the metal-ligand bond strength is given. The results compared very well with those obtained from vibrational spectra. (C) 2000 Elsevier Science B.V.
- Keuleers,Janssens,Desseyn
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p. 125 - 133
(2008/10/08)
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- Synthesis and thermal studies of 2,4′-bipyridyl complexes of manganese(II) salts
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2,4′Bipyridyl (2,4′bipy or L) complexes of Mn(II) with the formulae MnL2X2·2H2O (X-=Cl, Br, NCS, NO3), MnLSO4·5H2O and MnL4(ClO4)2·2H2O were synthesized and characterized via the IR spectra and magnetic, and conductivity measurements. The nature of the Mn(II)-ligand coordination is discussed. The thermal decompositions of these compounds were studied in air atmosphere. The mode of decomposition depends on the anion present, but the final product in all cases is Mn3O4. Some of the intermediates (MnL2Cl2, MnLCl2, MnL2Br2, MnL2(NCS)2 and MnLSO4) formed during the pyrolysis are isomeric with 2,2′-bipy and 4,4′-bipy complexes.
- Czakis-Sulikowska,Kaluzna
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- Chlorination of niobium and tantalum ore
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The reaction of chlorine with columbite concentrate, a niobium and tantalum ore, was studied by thermogravimetry between 300° and 950°C. Nonisothermal and isothermal measurements were performed. Morphological evolution of solid reactants and elemental composition of particles were analyzed by SEM and EDXS, respectively. The growth of crystals, high in Ta and Nb content, was observed. The Ta content in remaining samples was greater as the chlorination temperature increased. A scheme of the reaction mechanism is proposed.
- Gonzalez,Gennari,Bohe?,Del C. Ruiz,Rivarola,Pasquevich
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- Hemoglobin composition and preparation thereof
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The described invention relates to an essentially stroma-free hemoglobin composition evidencing properties suitable for use as a universally applicable blood plasma expander and to a method for the preparation thereof. Typical, of these properties are desirable oxygen affinity values, desirable vascular retention time and substantial absence of toxic side effects. The described composition comprises human hemoglobin cross-linked intramolecularly through the beta-chains and polymerized with glutaraldehyde. Intramolecular cross-linking is typically effected with 2-nor-2-formylpyridoxal 5-phosphate or a bis-pyridoxal polyphosphate.
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- Thermal analysis of some complexes with malonamide
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In alkaline medium, malonamide forms anionic planar complexes [ML2](2-) . xH2O where M is Ni or Cu. Thermograms and vibrational spectra clearly indicate that three different nickel anion complexes could be isolated, with x being respectively 2, 1 and 0. O
- De Beukeleer, S. H. J.,Desseyn, H. O.,Perlepes, S. P.,Mullens, J.
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p. 149 - 162
(2008/10/09)
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- Synthesis and Reactivity of N,N-Dialkylcarbamato Complexes of Manganese(II). Crystal and Molecular Structure of , a Hexamer with Four Five-co-ordinated Manganese(II) Atoms
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The compounds n> (R = Me, Et, or Pri) have been prepared by treating (cp = η5-C5H5) with CO2-NHR2 in organic solvents.These reactions may possibly involve the addition compound .NHR2.In the case of R =Et, the adduct has been isolated and characterized, and the space group, crystal data, and metal connectivity established.The structure of the N,N-diethylcarbamato complex has been solved by X-ray diffraction.Crystal data: monoclinic, space group C2/c, a = 18.546(3), b = 19.287(3), c = 24.877(3) Angstroem, β = 95.38(2) deg, R = 0.078.It consists of hexameric units , containing four five-co-ordinated Mn atoms, joined by bridging carbamato ligands.It was found to be unreactive towards nucleophiles, while by reaction with 2> the new complex has been obtained.Organic electrophiles react regioselectively at the oxygen or at the nitrogen atom of the carbamato ligand of the manganese complexes, and in the former case the CO2 fragment is retained in the reaction products.
- Belforte, Antonio,Calderazzo, Fausto,Zanazzi, Pier Francesco
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p. 2921 - 2926
(2007/10/02)
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- Preparation and thermal decomposition of halogenometallates. II. Tetrachlorometallates of tris (2,2′-dipyridyl) ruthenium(II)
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Five new derivatives of general formula [Ru(dipy)3]MCl4, where M=Cu(II), Zn(II), Mn(II), Fe(II) and Co(II), and [Ru(dipy)3][FeCl4]2 were synthesized, and their compositions and structures were confirm
- Bujewski, A.,Grzedzicki, K.,Blazejowski, J.,Warnke, Z.
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p. 961 - 968
(2008/10/08)
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- Spin cluster excitations in Ti2+-doped MnCl2
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Single-crystal absorption spectra of Ti2+ as an impurity in MnCl2 were recorded between 1.5 K and room temperature. A particular feature of these spectra is transitions to the low-energy 1Eg level of Ti2+ in the near-infrared region that are spin-forbidden on the single center. These bands appear entirely as a result of magnetic exchange with the surrounding Mn2+ ions. A one-parameter model based on a Ti2+(Mn2+)6 spin cluster was used to characterize the spectra. An excellent agreement between theory and experiment was found with a value for the Ti2+-Mn2+ exchange parameter of J = -6.2 cm-1. The emission spectrum at 45 K was also found to agree with the predictions of the model. The lowest energy ground-state level is described by the function |15 14>, where 15 is the total spin of Mn2+ ions and 14 is the overall spin of the cluster.
- Jacobsen, Stuart M.,Güdel, Hans U.,Smith, W. Ewen
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p. 2001 - 2005
(2008/10/08)
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- STUDIES ON TRANSITION-METAL PICOLINE COMPLEXES - I. PREPARATION AND THERMOANALYTICAL INVESTIGATIONS.
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A large number of transition-metal picoline halides were prepared, and their thermal decompositions were investigated by TG, DTG, DTA and thermomicroscopy. The compounds were classified on the basis of their thermal properties and two possible mechanisms of thermal decomposition were established.
- Liptay,Borbely-Kuszmann,Nagy
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