Cation Chemistry Research Articles

Electronic Transfer and Phase Transitions in Cationic Intercalation Chemistry in Low‐Dimensional Chalcogenides

AbstractBesides their striking physical properties, low‐dimensional solids have also a very rich chemical reactivity, of which the redox intercalation‐disintercalation processes represent an essential part. The intercalation of cations is the result of a coupled ion‐electron transfer reaction. The geometrical features associated to the ions are well known at present. However the role of the electron is oftentime restricted to a modification of the physical properties of the host structure. In this contribution it will be shown that the electronic transfer plays an essential role concerning the ability to intercalate and, also, largely governs the phase transitions that can be observed. Such phase transitions concern either the position taken by the intercalated cations or the host framework itself. They can be also related to a strong ion‐electron coupling.

Comparison of chemical flocculation and dissolved air flotation of anaerobically treated palm oil mill effluent

The effectiveness of chemical flocculation and dissolved air flotation process as applied to the secondary treatment of the anaerobically digested liquor of palm oil mill effluent (POME) was investigated and compared. Results indicated that the dissolved air flotation method was more efficient than chemical flocculation in an all round removal of pollutants from the digested liquor. Even though both methods were able to achieve a 97% removal of the suspended solids of the digested liquor, the removal of soluble matter of inorganic and organic origins was far from satisfactory. This is in general agreement with the recognised view of the superior efficiency of biological methods over physico-chemical methods in treating soluble substances. An explanation of the observed behaviour of the digested liquor in the presence of aluminium salt and polymeric flocculant in terms of the solution chemistry of polyelectrolyte and hydrolysable metallic cations was attempted.

Incubation Studies of the Fate of Organic Nitrogen in Soils Amended with Activated Sludge

AbstractMineralization of sludge organic N and the effect of transformations in nitrogen compounds on soil solution composition were studied in incubated soil‐sludge mixtures. Four soils were incubated with sludge at four mixing ratios (1–15% sludge) for 90 d at 35 °C under continuous flow of water saturated air. Soil‐water contents were maintained at 60% of the 0.033 MPa tension. The extent of ammonification was 41 to 61% of the amount of sludge organic N added. Both soil properties and sludge content affected the extent of ammonification. The soils' effect was relatively small. Only the clayey and sandy soils differed significantly (54.5 vs. 47.9%). The effect of sludge loading was more pronounced. At 1 and 5% sludge contents the ammonification was significantly greater (53 and 56% ammonified) than at 10% (48%) or 15% (43%) sludge contents. The reduced ammonification at the higher sludge and clay content might be related to the more intense nitrification‐induced salinization observed in these treatments. Sludge content and soil properties affected the initial rates of both ammonification and ammonia volatilization. Ammonification was linearly related to sludge and clay content, whereas the volatilization rate was similarly related to sludge content but inversely related to cation exchange capacity (CEC). Estimated half‐lifes for the added organic N is 2 to 8.5 d. Up to 87% of the ammonified sludge N, was lost as gaseous species, mostly as ammonia. Sludge application to soils and subsequent transformations could greatly influence soil solution chemistry and composition of exchangeable cations, depending mainly on its content.

ChemInform Abstract: Comprehensive Coordination Chemistry of Alkali and Alkaline Earth Cations with Macrocyclic Multidentates: Latest Position

ChemInform Abstract: Comprehensive Coordination Chemistry of Alkali and Alkaline Earth Cations with Macrocyclic Multidentates: Latest Position

Origin and mixing history of brines, Palo Duro Basin, Texas, U.S.A.

Formation waters in the Palo Duro Basin, Texas, U.S.A. fall into four major groups based on integrated chemical and isotopic characteristics: (1) interbed brines within the major Permian evaporite aquitard; these are the most chemically concentrated and 18O-rich fluids in the basin, and are interpreted as evaporatively concentrated sea water which has been hydrologically isolated since the Permian; (2) brines below the salt on the eastern side of the basin have Cl Br, divalent cation, and isotopic systematics indicating a mixture of evaporatively concentrated sea water and meteoric water of δD= −20‰; (3) brines below the salt on the western side of the basin have chemical and isotopic systematics suggesting a mixture of two pulses of meteoric water, one with δD= −20‰ and the other with δD= −55‰; and (4) waters above the salt have the isotopic composition of meteoric waters. Diagenetic alteration of the cation chemistry has occurred for brines within and below the salt. Aquifers below the salt on the eastern side are interpreted as having been charged with dense Permian evaporite brines which subsequently mixed in various amounts with a basin-wide pulse of Triassic meteoric water. On the western side the descending Triassic meteoric waters became saline by dissolution of halite and are currently mixing with a Tertiary pulse of meteoric water initiated by the Laramide uplift to the west. The hydrochemistry suggests flow on the western side of the basin and static conditions on the eastern side. An unrecognized, approximately N-S permeability restriction, or discontinuity in the potentiometric flow surface, is inferred for major aquifers in the central area of the basin.

ChemInform Abstract: Gaseous Negative Ions from Neutral Molecules and Positive Ions: New Information for Neutralization‐Reionization Mass Spectrometry.

AbstractCollisional electron transfer to mass‐selected cations or neutrals as an alternative route to negative ions is studied; the resulting mass spectra contain novel information on the structures and chemistry of the precursor cations and neutrals, as well as the product anions.

Schiff base complexes of lanthanides and actinides

The coordination chemistry of lanthanide and actinide cations with Schiff bases has been investigated and reviewed over the last few years. More recently, acyclic and macrocyclic ligands (including binucleating and/or compartmental ligands) have been synthesized and their interaction with f-ions studied. The formation of metal complexes with binucleating ligands is of interest because the opportunity is provided to study the intramolecular binding and possible activation of small molecules between the metal centres, along with magnetic exchange interactions and multielectron redox reactions. The facile generation of macrocyclic Schiff bases in the presence of alkaline earth metal cations has led to an interest in the use of lanthanide cations as templating agents in similar conditions. The comparable ion size suggests that such reactions should be successful. The actinides, with their high ionic radii and/ or unusual coordination geometry can produce and stabilize expanded macrocyclic ligands. For these condensation reactions keto-precursors and facultative amines have been used. The condensation products, often obtained by template synthesis are thus of the type where the head and the lateral units can be varied, with the consequent formation of macrocycles with different donor atoms and/or different cavity size.

ChemInform Abstract: Chemistry of Reactive Cations Derived from Sulfur Dioxide Analogues. Part 15. Reaction with Ketenimines.

ChemInformVolume 18, Issue 39 Heterocyclic Compounds ChemInform Abstract: Chemistry of Reactive Cations Derived from Sulfur Dioxide Analogues. Part 15. Reaction with Ketenimines. R. LUX, R. LUX Org.-chem. Inst., TU Muenchen, D-8046 GarchingSearch for more papers by this authorG. KRESZE, G. KRESZE Org.-chem. Inst., TU Muenchen, D-8046 GarchingSearch for more papers by this author R. LUX, R. LUX Org.-chem. Inst., TU Muenchen, D-8046 GarchingSearch for more papers by this authorG. KRESZE, G. KRESZE Org.-chem. Inst., TU Muenchen, D-8046 GarchingSearch for more papers by this author First published: September 29, 1987 https://doi.org/10.1002/chin.198739150Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume18, Issue39September 29, 1987 RelatedInformation

Coordination chemistry of alkali and alkaline earth cations: the structure of bis(3,5-dinitrobenzoato)(tetraethyleneglycol)strontium(II) monohydrate

Coordination chemistry of alkali and alkaline earth cations: the structure of bis(3,5-dinitrobenzoato)(tetraethyleneglycol)strontium(II) monohydrate

Chemistry and synthetic utility of cobalt-complexed propargyl cations

Chemistry and synthetic utility of cobalt-complexed propargyl cations

ChemInform Abstract: Mass Spectrometry for Investigations of Gas‐Phase Radical Cation Chemistry. The Two Step Cycloaddition of the Benzene Radical Cation and 1,3‐Butadiene.

Abstract Mass spectrometric techniques are now used extensively for the study of gas-phase radical cation chemistry. The generation and structural properties, the unimolecular and bimolecular chemistry of some representative radical cation systems, and the methods of study are reviewed. The structure of the ionmolecule adduct produced in the reaction of the benzene radical cation and neutral 1,3-butadiene was investigated by collisionally stabilizing the adduct and then acquiring its collision-activated decomposition spectrum. The CAD spectrum of the adduct changes dramatically as a function of the degree of collisional stabilization. This observation is interpreted in terms of two distinct structures for the adduct. The species that is stabilized at 0.7 Torr has a CAD spectrum similar to the 2-phenyl-2-butene radical cation. The second structure, stabilized at 0.1 Torr, has a CAD similar to that of 1-methylindan. The results of these experiments are interpreted in terms of a two-step cycloaddition mechanism for the formation of the 1-methylindan radical cation.

Ion Mass Balances and Seasonal Fluxes from Four Acidic Brownwater Streams in Nova Scotia

Precipitation and four brownwater streams in southwestern Nova Scotia were sampled for 3–5 yr. Precipitation cation chemistry was dominated by H+ (44% of cation equivalents) and Na+ (38%), while anions were dominated by Cl− (44%), SO42− (41%), and NO3− (15%); mean annual pH was 4.6, and acidity was correlated with concentrations of SO42− (r = 0.90) and NO3− (r = 0.82). Surface water chemistry was dominated by Na+ (51% of cation equivalents), Mg2+ (17%), and Ca2+ (16%), while H+ averaged only 4%; anions were dominated by Cl− (53%), organic anions (23%), and SO42− (21%); H+ was not strongly related to concentrations of other ionic constituents (the most consistent correlation was with sulfate, but this was weak and accounted for <30% of the variation). Hydrogen ion was consumed in all four watersheds by an average value of >75%. Water flow was by far the strongest determinant of annual pattern of flux of chemical constituents from the watersheds. Seasonal variations of concentration were of relatively small magnitude and had much less influence on patterns of flux.

Coordination chemistry of alkali and alkaline earth cations—synthesis and X-ray structural analysis of sodium(picrate)-(1,10-phenanthroline) 2

The complex Na(Pic)(PHEN) 2 (Pic = picrate, Phen = 1,10-phenanthroline) is unique in being a cluster with two independent Na ions in the asymmetric unit. Na(1) is seven-coordinated involving two N atoms of two Phen molecules (NaN, 2.492–2.622 Å), phenoxide O (NaO −, 2.381 Å) and an o-nitro-oxygen (NaONO, 2.584 Å) of Pic(1) and also to the phenoxide O (NaO −, 2.656 Å) of Pic(2). Na(2) is six-coordinated through four N atoms of the two other Phen molecules (NaN, 2.510–2.570 Å), phenoxide O (NaO −, 2.317 Å) and o-nitro-oxygen (NaONO, 2.592 Å) of Pic(2). Thus Pic(2) serves as a linkage residue between two clusters. The Phen molecules are planar and nearly perpendicular to each other in either cluster.

The lanthanoid(II) halides: Still a veritable gold mine

The preparative and structural chemistry of the lanthanoid(II) halides is reviewed with emphasis on recent developments in preparatory procedures and phase studies. The chemistry of those systems where uncertainty remains is emphasized. Some recent results of lanthanoid(II) solution chemistry and of both mixed cation and mixed anion solid state ternary-phase chemistry are discussed.

Comparative sulphur cation chemistry in a hydrocarbon flame with H2S, OCS, and SO2 additives

A fuel-rich, conical, premixed, methane–oxygen flame at atmospheric pressure was doped separately with 0.2 mol% of H2S, OCS, and SO2 to probe the chemistry of sulphur at its source during combustion. These three additives represent a broad range of fuel-sulphur contaminants since they occur early, intermediate, and late in the sulphur oxidation sequence. A wide variety of sulphurous cations, formed by chemical ionization reactions, is observed for each additive by sampling the flame into a mass spectrometer. The total ionization profile measured along the flame axis is enhanced in the reaction zone when a sulphur additive is present; the mechanism involves the formation of sulphurous negative ions which reduces the rates of cation loss by electron–ion recombination and ambipolar diffusion. Mass spectra measured in the mass range 10–110 u at fixed points on the flame axis are very similar for all three additives, and are not helpful in the identification of the additive. However, the general presence of sulphur is evident from large signals measured near the reaction zone at five principal mass numbers; namely, 45 u (CHS+), 47 u (CH3S+), 58 u (C2H2S+), 59 u (C2H3S+), and 69 u (C3HS+) related to CS, thioformaldehyde, thioketene, and C3S.

A quantum chemical investigation of the unimolecular chemistry of the formic acid radical cation and some of its isomers

The potential energy surface of the CH 2O 2 +· system has been investigated by applying ab initio quantum chemical methods. The following isomers were located on the potential energy surface: the formic acid radical cation, HCOOH +· [ground state, 1, and the first excited state, 5], the dihydroxymethylene radical cation, C(OH) 2 +·, 2, and the two dimeric species H 2OCO +·, 3, and COH 2O +·, 4. Isomerization barriers as well as barriers for fragmentations to give ions at m/z 45 (loss of H · from HCO 2H +·), m/z 29 (loss of OH ·) and m/z 18 (loss of CO) in the mass spectrum of formic acid have been calculated. For all except two of the processes studied, good agreement with experiment is found.

Pore water evolution during sediment burial from isotopic and mineral chemistry of calcite, dolomite and siderite concretions

Coal measures often contain concretions; segregations of diagenetic minerals originally formed within unconsolidated sediments. Three different types (calcite/pyrite, dolomite/pyrite and siderite) occurring spatially quite close together in the Central Pennine Region of England vary widely in carbon isotope composition (+10.35%. > δ 13 C > −21.49%.) and in major cation chemistry (Ca, Mg, Fe, Mn). Within some siderite concretions, very high Mn Fe ratios were found in central subsamples; these were also most enriched in 13C. The Fe Mg ratio decreases systematically from centre to edge (early, shallow to deeper, later precipitation). The calcite/pyrite and dolomite/pyrite concretions developed completely prior to significant burial. Both have high Mn Fe ratios but negative δ 13C values (calcite −21.49%., dolomite −8.67 to −10.48%.). All of these patterns can be equated precisely with theories of pore water evolution developed on the basis of geochemical investigations of modem sediments. Microbial processes (sulphate reduction, methanogenesis) contributed significantly, as did thermal decarboxylation (to siderite precipitated at considerable burial depth). Mn(IV) and Fe(III) acted differentially as oxidants; producing CO 2 and increasing alkalinity. The interplay of fresh and marine depositional waters is seen most obviously in the presence or absence of sulphate reduction. This controlled mineral type (iron sulphide or carbonate) as well as isotopic and mineral chemistry.

Transition-metal cation chemistry in 1 torr of helium: M+ + ethane reaction rates

Transition-metal cation chemistry in 1 torr of helium: M+ + ethane reaction rates

ChemInform Abstract: Chemistry of Reactive Cations Derived from Sulfur Dioxide Analogues.

AbstractOnly the cationic sulfur diimide (I) reacts with alkenes (III) to yield the [2 + 2] cycloadducts (IV) regioselectively; 83 these which may be hydrolyzed by bases to the sulfinic acid amides (V).

Mass spectrometry for investigations of gas-phase radical cation chemistry : The two step cycloaddition of the benzene radical cation and 1,3-butadiene

Mass spectrometric techniques are now used extensively for the study of gas-phase radical cation chemistry. The generation and structural properties, the unimolecular and bimolecular chemistry of some representative radical cation systems, and the methods of study are reviewed. The structure of the ionmolecule adduct produced in the reaction of the benzene radical cation and neutral 1,3-butadiene was investigated by collisionally stabilizing the adduct and then acquiring its collision-activated decomposition spectrum. The CAD spectrum of the adduct changes dramatically as a function of the degree of collisional stabilization. This observation is interpreted in terms of two distinct structures for the adduct. The species that is stabilized at 0.7 Torr has a CAD spectrum similar to the 2-phenyl-2-butene radical cation. The second structure, stabilized at 0.1 Torr, has a CAD similar to that of 1-methylindan. The results of these experiments are interpreted in terms of a two-step cycloaddition mechanism for the formation of the 1-methylindan radical cation.