- The electronic structures of an isostructural series of octahedral nitrosyliron complexes {Fe-NO}6,7,8 elucidated by Mossbauer spectroscopy
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From the reaction of cis-[(cyclam)Fe(III)(Cl)2]Cl (cyclam = 1,4,8,11- tetraazacyclotetradecane) with hydroxylamine in water the octahedral nitrosyliron complexes trans-[(cyclam)Fe(NO)Cl](ClO4) (1) and cis- [(cyclam)Fe(NO)I]I (2) have been isolated as crystalline solids. EPR spectroscopy and variable-temperature susceptibility measurements established that 1 possesses an S = 1/2 and 2 an S = 3/2 ground state; both species are of the {Fe-NO}7 type. Electrochemically, 1 can be reversibly one-electron oxidized yielding trans-[(cyclam)Fe(NO)Cl]2+, an {Fe-NO}6 species, and one-electron reduced yielding trans-[(cyclam)Fe(NO)Cl]0, an {Fe-NO}8 species. These complexes have been characterized in CH3CN solutions by UV- vis and EPR spectroscopy; both possess a singlet ground state. All of these nitrosyliron complexes, including [LFe(NO)(N3)2] (S = 3/2; L = 1,4,7- trimethyl-1,4,7-triazacyclononane) and [L'Fe(NO)(ONO)(NO2)](ClO4) (S = 0; L' = 1,4,7-triazacyclononane), have been studied by variable-temperature Mossbauer spectroscopy both in zero and applied fields. The oxidation of 1 is best described as metal-centered yielding a complex with an Fe(IV) (S = 1) coupled antiferromagnetically to an NO- (S = 1), whereas its reduction is ligand-centered and yields a species with a low-spin ferric ion (S = 1/2 ) antiferromagnetically coupled to an NO2- (S = 1/2 ). In agreement with Solomon et al. (J. Am. Chem. Soc. 1995, 117, 715) both {Fe-NO}7 (S = 3/2) species in this work are described as high-spin ferric (S = 5/2) antiferromagnetically coupled to an NO- (S = 1). Complex 1 is proposed to contain an intermediate spin ferric ion (S = 3/2) antiferromagnetically coupled to NO- (S = 1). The alternative descriptions as low-spin ferric antiferromagnetically coupled to NO- (S = 1) or low-spin ferric with an NO- (S = 0) ligand are ruled out by the applied field Mossbauer spectra.
- Hauser, Christina,Glaser, Thorsten,Bill, Eckhard,Weyhermueller, Thomas,Wieghardt, Karl
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- Reaction of a mixture of bismuth and iron oxides with chlorine and sulfur dioxide
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The processes in a heterogenous multicomponent system Bi2O 3-Fe2O3-Cl2-SO2. are explored. In the temperature range 300-700°C is clearly developed mutual influence of chemical reactions at introducing to the system of an additional component: chloridosublimation of both bismuth and iron in the presence of SO2 and chloridosublimation of bismuth at adding iron oxide to bismuth oxide are accelerated. In the region of the higher temperatures the possible chemical reactions in the system proceed independently: SO2 only dilutes chlorine and mutual influence of bismuth and iron oxides is not found.
- Derlyukova,Vinokurova
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- Density functional theory assessment of the thermal degradation of diclofenac and its calcium and iron complexes
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Thermogravimetric analyses of diclofenac sodium, its Ca2+ and Fe3+ complexes manifested a decreasing trend of the onset decomposition temperatures at which these compounds dissociated. The drop in the temperature was metal ion dependent; the sodium salt showed thermal stability up to 245°C, whereas the complexes started their degradation processes at temperatures starting from 90°C. While G* for the cleavage of the acetate moiety in the sodium salt was 63.76 kJmol-1, it was 82.06 and 140.57 kJmol-1 in the cases of Ca2+ and Fe3+, respectively. However, their complete fusion took place at 187.65, 150.34 and 98.77°C, respectively, displaying a reversed trend which is probably indicative of some catalytic part on the binding metals. Using the Gaussian 98 W package of programs, ab initio molecular orbital treatments were applied to diclofenac and its Ca2+ and Fe3+ metal complexes to study their electronic structure at the atomic level. The thermochemistry of diclofenac sodium was followed through the TG fragmentation peak temperatures using the density functional theory calculations at the 6-31G(d) basis set level. The FT-IR data were in good agreement with the theoretically calculated values. Single point calculations at the B3LYP/ 6-311G(d) level of theory, were used to compare the geometric features, energies and dipole moments of these compounds to detect the effect of the binding metal ions on the thermal dissociation of their diclofenac complexes.
- Kenawi, Ihsan M.
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- Reactions of wüstite and hematite with different chlorinating agents
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Chlorination of wüstite (Fe(1-x)O) and hematite (Fe2O3) with Cl2 + CO and Cl2 + N2 was studied by thermogravimetric analysis using non-isothermal conditions up to about 1000°C. The wüstite
- Kanari,Allain,Gaballah
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- Kinetics of the chlorination of hematite
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The chlorination of hematite was studied by thermogravimetry between 600 and 950°C. The role of convective mass transfer into the boundary layer surrounding the sample, gaseous diffusion into the sample pores, and the effect of the reaction temperature on the reaction rate were analyzed in order to determine the rate-controlling regime. In the 750-950°C temperature range, the reaction rate was significantly affected by diffusion of Cl2 through the gas film surrounding the sample. In the 600-750°C range a mixed rate-controlling regime with an apparent activation energy of 200 kJ mol-1 was observed. The diffusion of iron chlorides and oxygen out of the sample pores is proposed as the slowest diffusion step.
- Gennari,Pasquevich
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- Reaction of carotenoids and ferric chloride: Equilibria, isomerization, and products
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In the oxidation of carotenoids, ethyl all-trans-8a?2-apo-?2-caroten-8a?2-oate and all-fraws-?2-carotene, with ferric chloride, several equilibria occur between Fe3+, Fe2+, Cl-, the neutral carotenoid, and its radical cation and dication. The radical cation and dication were found to abstract an electron from Fe2+. Isomerization of carotenoids occurs during the oxidation. In the presence of air, a stable product is formed in high yield during the oxidation. 1H NMR, LC-MS, and optical studies show that this product is the 5,8-peroxide of the starting material. A mechanism for the formation of this compound is proposed.
- Gao, Yunlong,Kispert, Lowell D.
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- Kinetics of hematite chlorination with Cl2 and Cl2 + O2: Part I. Chlorination with Cl2
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Preliminary tests of the chlorination of two iron oxides (wüstite and hematite) in various chlorinating gas mixtures were performed by thermogravimetric analysis (TGA) under non-isothermal conditions. Wüstite started to react with chlorine from about 200 °C generating ferric chloride and hematite as the final reaction products. The presence of a reducing and oxidizing agent in the chlorinating gas mixtures influenced the chlorination reactions of both iron oxides, during non-isothermal treatment, only at temperatures higher than 500 °C. The chlorination kinetics of hematite with Cl2 have been studied in details between 600 and 1025 °C under isothermal chlorination. The values of the apparent activation energy (Ea) were about 180 and 75 kJ/mol in the temperature ranges of 600-875 and 875-1025 °C, respectively. The apparent reaction order with respect to Cl2 was found to be 0.67 at 750 °C. Mathematical model fitting of the kinetics data was carried out to determine the most probable reaction mechanisms.
- Kanari,Mishra,Filippov,Diot,Mochón,Allain
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- Effect of SO2 on chlorination of Bi2O3 + Fe2O3 mixtures
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The reaction of Bi2O3 + Fe2O3 mixtures with chlorine and SO2 at 250-700°C is studied. At 300-500°C, the degree of bismuth chloride sublimation from the oxide mixture increases in the presence of SOsu
- Derlyukova,Vinokurova,Anufrieva
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- An overview study of chlorination reactions applied to the primary extraction and recycling of metals and to the synthesis of new reagents
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Energy intensive classical metallurgical processes, the depletion of high-grade ores and primary sources push the scientific and technical communities to treat lean and complex ores as well as secondary metal resources for the recovery of valuable metals.
- Kanari,Allain,Joussemet,Mochón,Ruiz-Bustinza,Gaballah
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- Oxidation of Fe(III) to Fe(VI) by the Fe(CN) 63- ion in strong solution of alkalis
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Ferricyanide ions oxidize Fe(III) up to Fe(VI) in 7-11 M KOH solutions and 10-16 M NaOH solutions. The completeness of the oxidation increases with increasing alkali and ferricyanide concentrations. The presence of KNO 2, KAc, and K2
- Shilov,Gogolev
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p. 1773 - 1777
(2010/02/16)
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- Crystal growth, single-crystal structure refinement and unusual ligand-field splittings of lazulite-type oxidephosphates MTi2O 2(PO4)I (M = FeII, CoII, Ni II)
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Single crystals of oxidephosphates MTi2O2(PO 4)2 [M: Fe (dark red), Co (pinkish red), Ni (green)] with edge-lengths up to 0.4 mm were grown by chemical vapour transport. FeTi 2O2(PO4)2 and CoTi2O 2(PO4)2 are isotypic to NiTi2O 2(PO4)2. The crystal structure of the latter was previously solved from powder data [FeTi2O2(PO 4)2 (data for CoTi2O2(PO 4)2 and NiTi2O2(PO4) 2 in brackets): monoclinic, P21/c, Z = 2, a = 7.394(3) (7.381(6), 7.388(4)) A, b = 7.396(2) (7.371(5), 7.334(10))A, c = 7.401(3) (7.366(6), 7.340(3)) A, β = 120.20(3) (120.26(6), 120.12(4))°, R1 = 0.0393 (0.0309, 0.0539) wR2 = 0.1154 (0.0740, 0.1389), 2160 (1059, 1564) independent reflections, 75 (76, 77) variables]. The single-crystal study allowed improved refinement using anisotropic displacement parameters, yielded lower standard deviations for the structural parameters and revealed a small amount of cation disordering. Twinning and cation disordering within the structures are rationalized by a detailed crystallographic classification of the MTi2O 2(PO4)2 structure type in terms of group-subgroup relations. The structure is characterized by a three-dimensional network of [PO4] tetrahedra and [MIITi2O 12] groups formed by face-sharing of [MIIO6] and [TiO6] octahedra. Electronic absorption spectra of MTi 2O2(PO4)2 in the UV/VIS/NIR region show rather large ligandfield splittings for the strongly trigonally distorted chromophors [MIIO6] (M = Fe, Co, Ni) with interelectronic repulsion parameters beeing slightly smaller than in other phosphates. Interpretation of the spectra within the framework of the angular overlap model reveals a significant second-sphere ligand field effect of TiIV ions on the electronic levels of the NiII and CoII.
- Schoeneborn,Glaum
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p. 2568 - 2578
(2008/10/09)
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- Catalyst for oxidation of methanol to formaldehyde
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Catalysts for oxidation of methanol to formaldehyde, comprising a catalytic mixtures of Fe2(MoO4)3 / MoO3, wherein the Mo/Fe atomic ratio ranges from 1.5 to 5, and a compound of cerium molybdenum and oxygen in a quantity from 0.1 to 10% by weight expressed as cerium.
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- Catalysts for oxidation of methanol to formaldehyde
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Catalysts for oxidation of methanol to formaldehyde, comprising a catalytic mixtures of Fe2(MoO4)3/MoO3, wherein the Mo/Fe atomic ratio ranges from 1.5 to 5, and a compound of cerium molybdenum and oxygen in a quantity from 0.1 to 10% by weight expressed as cerium.
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- Reactivity of ammonium halides: Action of ammonium chloride and bromide on iron and iron(III) chloride and bromide
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Ammonium chloride and bromide, (NH4)Cl and (NH4)Br, act on elemental iron producing divalent iron in [Fe(NH3) 2]Cl2 and [Fe(NH3)2]Br2, respectively, as single crystals at temperatures around 450°C. Iron(III) chloride and bromide, FeCl3 and FeBr3, react with (NH 4)Cl and (NH4)Br producing the erythrosiderites (NH 4)2[Fe(NH3)Cl5] and (NH 4)2[Fe(NH3)Br5], respectively, at fairly low temperatures (350°C). At higher temperatures, 400°C, iron(III) in (NH4)2[Fe(NH3)Cl5] is reduced to iron(II) forming (NH4)FeCl3 and, further, [Fe(NH3)2]Cl2 in an ammonia atmosphere. The reaction (NH4)Br + Fe (4:1) leads at 500°C to the unexpected hitherto unknown [Fe(NH3)6]3[Fe 8Br14], a mixed-valent FeII/FeI compound. Thermal analysis under ammonia and the conditions of DTA/TG and powder X-ray diffractometry shows that, for example, FeCl2 reacts with ammonia yielding in a strongly exothermic reaction [Fe(NH3) 6]Cl2 that at higher temperatures produces [Fe(NH 3)]Cl2, FeCl2 and, finally, Fe3N.
- Bremm, Stephan,Meyer, Gerd
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p. 1875 - 1880
(2008/10/08)
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- Kinetics of oxychlorination of chromite Part I. Effect of temperature
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Nonisothermal thermogravimetric (TG) analysis was used to evaluate the reactivity of a chromite mineral [(Fe2+, Mg)(Cr, Al, Fe3+)2O4] towards Cl2 + CO, Cl2 + N2 and Cl2 + O2 gaseous mixtures up to 1000°C. Full chlorination and volatilization of reaction products were achieved at about 975°C using Cl2 + CO, while only about 40% of the sample have reacted at 1000°C using Cl2 + N2 and Cl2 + O2. The effect of the temperature on the oxychlorination with Cl2 + O2 of the chromite mineral was studied between 600 and 1050°C using isothermal TG measurements. The results show that the oxychlorination of chromite occurs in two stages. The initial stage of the oxychlorination was characterized by average values of apparent activation energy of about 151 and 57 kJ/mol for the temperatures lower and higher than 825°C, respectively. While a value of about 262 kJ/mol was found for the second stage of the oxychlorination process between 925 and 1050°C. The effects of temperature on the oxychlorination of the simple chromite constituents (Cr2O3, Fe2O3 and MgO) were also studied.
- Kanari,Gaballah,Allain
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p. 143 - 154
(2008/10/08)
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- Use of chlorination for chromite upgrading
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The chlorination of a chromite concentrate was studied between 600 and 1000°C. The reaction products were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and chemical analyses. Chlorination of a chromite concentrate at about 700°C allowed the extraction of about 50% of the iron, thus doubling the Cr/Fe ratio in the treated concentrate. Aluminum chloride was tested as a chlorinating agent in the presence of a reducing atmosphere. The effect of temperature on the kinetics of chromite chlorination was studied between 900 and 1040°C using thermogravimetric analysis (TGA). Temperature effects changed significantly with reaction extent. The initial stage of the chlorination was characterized by an apparent activation energy of about 112 kJ/mol, while a value of about of 269 kJ/mol was found for reaction extents greater than 0.4. (C) 2000 Elsevier Science B.V.
- Kanari,Gaballah,Allain
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p. 109 - 117
(2008/10/08)
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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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- METHOD OF SYNTHESIZING AN ENDONUCLEASE INHIBITOR AND ANALOGS THEREOF
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There is disclosed a method of synthesizing a compound of the formula and novel analogs of the formula where R and R1 are fully defined. These compounds exhibit beneficial antiviral properties especially as inhibitors of the influenza virus
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- 4-substituted azetidinones as precursors to 2-substituted-3-carboxy carbapenem antibiotics and a method of producing them
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New 4-substituted azetidinones having the formulae I and II: STR1 wherein X is oxygen, sulfur or a moiety of the formula NR6 where R1, R2, R3, R4, R5 and R6 are defined hereafter, which are intermediates for the preparation of carbapenem and carbacephem antibacterials and processes for producing such antibacterials through the utilization of an acid mediated ring closure reaction.
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- 4-substituted azetidinones as precursors to 2-substituted-3-carboxy carbapenem antibiotics and a method of producing them
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New 4-substituted azetidinones having the formulea I and II: STR1 with R1, R2, R3, R4, R5 and X defined hereafter, which are intermediates for the preparation of carbapenem and carbacephem antibacterials and processes for producing such antibacterials through the utilization of an acid mediated ring closure reaction.
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- Standard enthalpies of formation of crystalline iron chlorides
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The enthalpies of the reactions of Br2(l), Fe(c), FeCl2(c), FeCl3(c), KCl(c) and KBr(c) with a solution of KBr*0.43Br2*0.12HBr*50.78H2O at 298.15 have been measured in the dissolution calorimeter with isothermal jacket of the LKB-8700 apparatus.By combining the results with published data we calculated the values ΔfH0(FeCl2, c, 298.15 K) = -340.87 +/- 0.47 kJ mol-1 and ΔfH0(FeCl3, c, 298.15 K) = -395.30 +/- 0.67 kJ mol-1
- Evdokimova, V. P.,Efimov, M. E.
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p. 1226 - 1227
(2007/10/02)
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- Brain-specific drug delivery
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The subject compounds, which are adapted for the site-specific/sustained delivery of centrally acting drug species to the brain, are: (a) compounds of the formula wherein [D] is a centrally acting drug species, and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine pyridinium salt redox carrier, with the proviso that when [DHC] is STR1 wherein R is lower alkyl or benzyl and [D] is a drug species containing a single NH2 or OH functional group, the single OH group when present being a primary or secondary OH group, said drug species being linked directly through said NH2 or OH function group to the carbonyl function of [DHC], then [D] must be other than a sympathetic stimulant, steroid sex hormone or long chain alkanol; and (b) non-toxic pharmaceutically acceptable salts of compounds of formula (I) wherein [D] is a centrally acting drug species and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine pyridinium salt redox carrier. The corresponding ionic pyridinium salt type drug/carrier entitles [D--QC]+ X- are also disclosed.
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- Psoralen-nucleoside adducts and method for their preparation
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A method for the stereoselective snythesis of a cis-syn, furan-side mono-adducted linear furocoumarin:nucleoside adduct, which comprises reacting a linear furocoumarin with a nucleophilic acid to form a 3,4-dihydro-4-substituted linear furocoumarin intermediate, and contacting the intermediate with a nucleoside under photoactivating conditions. The reaction produces a cis-syn, furan-side, mono-adducted 3,4-dihydro-4-substituted linear furocoumarin:nucleoside adduct which can then be deblocked to give the final product under mild conditions.
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- Zur Kinetik des heterogenen Halogenaustausches zwischen Kaliumfluoroferraten und gasfoermigem CCl4
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The reaction of solid KFeF4 respectively K3FeF6 with gaseous CCl4 was investigated under differential conditions.From temperature- and partial pressure dependence of the specific rate of reaction the kinetical parameters have been determined (ΔH(excit.)KFeF4 = 25.7 kJ/mol; ΔH(excit.)K3FeF6 = 40.1 kJ/mol) and the kinetic laws have been estimated.The chemical reactivity of the fluoroferrates is correlated with that of alkaline fluorides up to one dimension lower.A change in the mechanism leads to a new increase of the rate of reaction because there is now an activation of CCl4 by the reaction products for example FeCl3
- Kemnitz, E.,Hass, D.
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p. 937 - 944
(2007/10/02)
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- Brain-specific dopaminergic activity involving dihydropyridine carboxamides, dihydroquinoline and isoquinoline carboxamides
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A brain-specific dopaminergic response is elicited in a patient in need of such treatment, e.g., a patient afflicted with Parkinson's disease of hyperprolactinemia, by administering thereto a therapeutically effective amount of preferably catechol protected dopamine tethered to a reduced, blood-brain barrier penetrating lipoidal form [D-DHC] of a dihydropyridine pyridinium salt type redox carrier, e.g., 1,4-dihydrotrigonelline. Oxidation of the dihydropyridine carrier moiety in vivo to the ionic pyridinium salt type dopamine/carrier entity [D-QC]+ prevents elimination thereof from the brain, while elimination from the general circulation is accelerated, resulting in significant and prolongedly sustained brain-specific dopaminergic activity.
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- COMPARATIVE THERMOGRAVIMETRIC STUDY OF CHLORINATIONS OF HEMATITE AND WUSTITE.
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The reactions of hematite and wustite with Cl//2, COCl//2, CO plus Cl//2 and gaseous CCl//4 were studied by thermogravimetry, X-ray diffraction and computer-assisted thermodynamic calculations. During the chlorination of hematite, only gaseous products were formed. The apparent activation energies were calculated from the isothermal TG curves. The chlorination of wustite involves the formation and transformation of a series of solid chloride products. FeCl//2(s), FeCl//3(s) and FeOCl(s) were found as intermediates during chlorination with Cl//2 or Cl//2 plus CO, while only FeCl//2(s) was detected in reactions with COCl//2 oe CCl//4. The chlorinations of the iron oxides with various agents were compared, and the differences in reactivity sequences were established.
- Bertoti,Pap,Szekely,Babievskaya
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p. 281 - 292
(2008/10/08)
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- Antianaemic composition and a process for producing the same
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A process for producing an organoiron(II) compound-containing antianaemic composition which comprises cultivating a yeast in a saccharide-containing nutrient medium therefor in the presence of an iron compound to form a cultured broth comprising an organoiron(II) compound, alcohol and water and removing the alcohol from the cultured broth to an extent that the resulting cultured broth has an alcohol content of less than about 1% by volume, and an antianaemic composition produced thereby. The antianaemic composition of the present invention is very stable, and excellent in absorbability into a living body and incorporation of iron into hemoglobin.
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- Brain-specific drug delivery
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The subject compounds, which are adapted for the site-specific/sustained delivery of centrally acting drug species to the brain, are: (a) compounds of the formula wherein [D] is a centrally acting drug species, and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine pyridinium salt redox carrier, with the proviso that when [DHC] is STR1 wherein R is lower alkyl or benzyl and [D] is a drug species containing a single NH2 or OH functional group, the single OH group when present being a primary or secondary OH group, said drug species being linked directly through said NH2 or OH functional group to the carbonyl function of [DHC], then [D] must be other than a sympathetic stimulant, steroid sex hormone or long chain alkanol; and (b) non-toxic pharmaceutically acceptable salts of compounds of formula (I) wherein [D] is a centrally acting drug species and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine pyridinium salt redox carrier. The corresponding ionic pyridinium salt type drug/carrier entities [D-QC]+ Y- are also disclosed.
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- Exchanging fluorine for chlorine in a chlorinated pyridine with an alkali metal fluoride
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A process for preparing a fluoropyridine compound by reacting a chlorinated pyridine compound with a molar excess of an alkali metal fluoride, especially potassium fluoride, in the presence of a catalytic amount of a catalyst selected from halides of organometals and halides of metals of the iron, nickel and copper groups, and which is preferably FeCl3, whereby at least one chlorine atom of the chlorinated pyridine compound is replaced by a fluorine atom. Of special interest is the preparation of 3,5-dichloro-2,4,6-trichloropyridine from pentachloropyridine. The compounds prepared by such a process are useful for the preparation of agriculturally-useful fluoropyridines.
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- Brain-specific drug delivery
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Centrally acting drug species are site-specifically/sustainedly delivered to the brain by administering to a patient in need of such treatment a therapeutically effective amount of the target drug species [D] tethered to a reduced, blood-brain barrier penetrating lipoidal form [D-DHC] of a dihydropyridine pyridinium salt type redox carrier. Oxidation of the dihydropyridine carrier moiety in vivo to the ionic pyridinium salt type drug/carrier entity [D-QC]+ prevents elimination thereof from the brain, while elimination from the general circulation is accelerated, and subsequent cleavage of the quaternary carrier/drug species results in sustained delivery of the drug [D] in the brain and facile elimination of the carrier moiety [QC]+.
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- Dyestuffs and their use in photographic material
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The new compounds of the general formula STR1 where R1 is hydrogen, alkyl or cyclic alkyl, R2 and R3 are each hydrogen, alkyl, a carboxylic acid, ester or amide group or cyano, and R4, R5 and R6 are each alkyl or aryl, are useful as antihalation dyes and as image dyes in photographic materials for dye-bleaching processes.
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- Evidence for volatile compounds in the Fe2O3-HCl-H2O-FeCl3 system
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A spectrophotometric and mass spectrometric study of vapors generated by heating various mixtures in the Fe2O3-HCl-H2O-FeCl3 system is described. The behavior observed in the temperature range 140-350°C is explained by assuming that along with Fe2Cl6 and FeCl3 the molecule H2OFeCl3 is present at significant concentrations in the vapor phase. An estimated molar absorptivity of 5000 M-1 cm-1 at 360 nm is used with the equilibrium absorbance data to derive a standard enthalpy of formation of -141 kcal mol-1 and a standard entropy of 113 cal mol-1 deg-1 for H2OFeCl3(g) at 500 K.
- Gregory
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p. 3750 - 3754
(2008/10/08)
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- Process for 4-(D-3-amino-3-carboxypropoxy)-phenylglyoxylic acid oxime derivatives
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Process for 4-(D-3-amino-3-carboxypropoxy)phenylglyoxylic acid oxime as an amino-protected ester comprising alkylating an amino-protected D-methionine silyl ester with an alkyl or benzyl iodide; cyclizing the alkylsulfonium iodide to an amino-protected D-homoserine lactone; hydrolyzing the lactone to an amino-protected D-homoserine in aqueous base; coupling, to form an ether, the amino-protected D-homoserine as an ester with an ester of 4-hydroxyphenylglyoxylic acid; and forming the oxime of the ether or alternatively coupling the D-homoserine ester with a protected-oxime of an esterified 4-hydroxyphenylglyoxylic acid. The product is useful in preparing the antibiotic FR 1923.
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- Photodecomposition and Charge Transfer Complexes of Acetylferrocene in Binary Solvents
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Photoreactions of acetylferrocene in equimolar binary solvents: CCl4 - cyclohexane and C2Cl4 - cyclohexane were investigated.Photoproducts were identified and the relations between the quantity of photoproducts, their quantum yield, the amount of decomposed acetylferrocene and exposure time and wavelength were determined.Equilibrium constants K and molar extinction coefficients εc of the CT complexes formed between acetylferrocene and halogen derivative were determined. - Keywords: Acetylferrocene; Charge transfer complexes; Photodecomposition; Quantum yield.
- Jaworska-Augustyniak, Anna
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p. 449 - 456
(2007/10/02)
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- Vaporization characteristics of ammonium tetrachloroferrate(III). The monoammine of iron(III) chloride in the vapor phase
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The behavior of NH4FeCl4 on heating is found to be complex. The iron(III) tends to be reduced by ammonia; however as HCl, a product of the reduction reaction, accumulates, the system stabilizes sufficiently to permit the study of vaporization equilibria. Absorption spectroscopy, mass spectrometery, and diaphragm gauge measurement of total pressures have been used to determine the composition of the vapor phase, and thermodynamic data for the reactions NH4FeCl4(C) = NH3FeCl3(g) + HCl(g) and NH4FeCl3(C) = FeCl2(s) + NH3(g) + HCl(g) are reported. The UV-visible absorption spectrum of NH3FeCl3 between 240 and 500 nm is given.
- Gregory
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p. 3667 - 3673
(2008/10/08)
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- Process for making 2-amino-4-hydroxyquinolines
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The reaction of isatoic anhydrides with malononitrile in a reaction-inert solvent in the presence of a base to produce 2-amino-3-cyano-4-hydroxy-quinolines and 2-amino-α,α-dicyanoacetophenones which are then hydrolyzed and decarboxylated under acid or base conditions to produce 2-amino-4-hydroxy-quinolines, useful as intermediates for preparation of 1-oxo-1H-6-alkoxy-pyrimido[1,2-a]quinoline-2-carboxylic acids and esters of value as antiallergy agents.
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- Catalytic Property of Calcined Iron Sulfate Treated with Hydrogen Chloride in Alkylation of Toluene and Benzene with Alkyl Chlorides
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Alkylation was carried out at room temperature over catalysts prepared by calcination of FeSO4, Fe2O3, and Fe(OH)3 in the air at various temperatures and subsequent exposure to HCl at room temperature for 20 min.The FeSO4-HCl catalysts heat-treated at 700 and 750 deg C showed very high activity and selectivity, the other catalysts except for the sulfate treated at 800 deg C being almost inactive.The FeSO4(700 deg C)-HCl catalyst was found to consist of FeCl3 and α-Fe2O3 by means of Moessbauer effect, the absorption peak areas being 14 and 86percent for portions of iron based on the chloride and oxide, respectively.The results of DTA and TGA experiments suggest that the coordinate bond of water molecule on FeCl3 of the FeSO4(700 deg C)-HCl catalyst is stronger than that on FeCl3 of the FeSO4 (600, 800, and 900 deg C)-HCl and commercial FeCl3.The FeSO4(700 deg C)-HCl catalyst showed a much higher activity than pure FeCl3.The iron(III) chloride formed by reaction of HCl and α-Fe2O3 obtained by thermal decomposition of the sulfate at 700 or 750 deg C was found to be a very strong Lewis acid catalyst.
- Arata, Kazushi,Hino, Makoto,Yabe, Katsumasa
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- 2-Amino-3-cyano-4-hydroxyquinolines
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The reaction of isatoic anhydrides with malononitrile in a reaction-inert solvent in the presence of a base to produce 2-amino-3-cyano-4-hydroxyquinolines and 2-amino-α,α-dicyanoacetophenones which are then hydrolyzed and decarboxylated under acid or base conditions to produce 2-amino-4-hydroxyquinolines, useful as intermediates for preparation of 1-oxo-1H-6-alkoxypyrimido[1,2-a]quinoline-2-carboxylic acids and esters of value as antiallergy agents.
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- Recovery of chlorine values from iron chloride by-produced in chlorination of ilmenite and the like
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The invention relates to the recovery of chlorine values from iron chloride by-produced from the chlorination of a titaniferous material containing more than 5% by weight iron oxide, and particularly from the carbo-chlorination of ilmenite, which, for example, can be the first stage in the so-called chloride route to form titanium dioxide pigment. The iron chloride which may be ferric chloride or ferrous chloride is subjected to a combination of reduction and oxidation reactions. In the reduction reaction, ferric chloride is dechlorinated to ferrous chloride by a reducing agent suitable for producing a chloride compound for recycle to the chlorination process or for sale and in the oxidation reaction ferrous chloride is oxidized to ferric oxide and ferric chloride, the ferric chloride being recycled to the reduction reaction. By this method the chlorine values are recovered from by-product iron chloride by a route which avoids the difficult reaction between ferric chloride and oxygen to produce chlorine and ferric oxide.
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- Process for producing N-phosphonomethylglycine salts
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Salts of N-phosphonomethylglycine are produced by forming a salt of N-phosphonomethyliminodiacetic acid with a salt-forming cation in an aqueous medium and then oxidizing the salt solution with an oxygen-containing gas in the presence of a platinum on activated carbon catalyst. The salts produced are useful as herbicides or plant growth regulants.
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- Preparation of haloalkyl esters
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Haloalkyl esters are prepared by reacting a saturated cyclic ether with a carboxylic acid or anhydride thereof and a hydrogen halide or hydrohalic acid in the presence of a Friedel-Crafts catalyst.
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- 2-Acyl-3-substituted cyclopentan-1-ones and process for their preparation
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1,3-Dicarbonyl compounds useful as medicines, agricultural chemicals, perfumes, and their intermediates are prepared by reacting a specific α,β-unsaturated carbonyl compound with a specific organic copper lithium compound in the presence of an aprotic inert organic solvent, and then reacting the reaction product with an organic carboxylic acid halide or anhydride. In particular, novel 2-acyl-3-substituted cyclopentan-1-ones and 2-acyl-3-substituted cyclohexan-1-ones having important physiological activities are provided.
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- Bis-chromone-tetrazole/hydroxamic/carboxylic acids
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There are described compounds of formula I, SPC1 in which R1, r2, r3, r4, r5 and R6, which may be the same or different, each represent hydrogen, halogen, hydroxy, alkyl C1 to 6, alkoxy C1 to 6, alkenyl C1 to 6; the alkyl and alkoxy groups optionally being substituted by hydroxy, alkoxy C1 to 6, halogen or phenyl, and X is a hydrocarbon group containing from 2 to 10 carbon atoms, which is optionally interrupted by an oxygen atom, and/or substituted by an -OH group, Ra is a group -COOH, or EQU1 and pharmaceutically acceptable derivatives thereof. There are also described methods of making the compounds and pharmaceutical, e.g. anti-allergic, compositions containing them.
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- O,O-diethyl-O-carboxamidophosphate esters
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Mites and insects, particularly aphids, are combated by applying as pest control agents one or more compounds of the structural formula EQU1 in which R is tert.butylphenyl; tert.butyl; 3,5-dimethylphenyl; 1-methyl-1-phenylthioethyl; 1-methyl-1-methylthioethyl; 1-cyclohexylthio-1-methylethyl; 1-cyclohexylthiopropyl; 1-ethylthio-1-methylethyl; 1-ethylthiopropyl or 1-ethylthioethyl.
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- Method for the purification of 6-methoxy-1-phenazinol 5,10-dioxide
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A novel improved procedure is described for the preparation of various metal complexes of 6-methoxy-1-phenazinol 5,10-dioxide by the reaction between 6-methoxy-1-phenazinol 5,10-dioxide and a metal salt or hydroxide in an aqueous suspension or a solution in aqueous mineral acid. Preferred metals disclosed as suitable for use in the process are calcium, strontium, magnesium and iron. Utility of the ferric chloride complex and the calcium complex in the purification of 6-methoxy-1-phenazinol 5,10-dioxide is also disclosed.
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- 2,3,4,5-Tetra hydro-5-oxo-1-benzothiepi N-4-carboxamide 1,1-dioxides
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Compounds of the formula: SPC1 Are disclosed. In the above formula, R1 is aryl such as benzene or a heterocycle such as pyridine, isoxazole, or thiazole. The aryl or heterocyclic group R1 is substituted or unsubstituted. R2 is hydrogen, lower alkyl, halogen, lower alkoxy, trifluoromethyl and the like. These compounds are useful as anti-inflammatory agents indicated in conditions such as rheumatoid arthritis.
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