Complex oxide minerals, aqueous

Parks, G. A. (1967), "Aqueous Surface Chemistry of Oxides and Complex Oxide Minerals Isoelectric Point and Zero Point of Charge," in Equilibrium Concepts in Natural Water Systems, Advances in Chemistry Series, No. 67, American Chemical Society, Washington, DC. 

Aqueous Surface Chemistry of Oxides and Complex Oxide Minerals... 

Parks, G.A. 1967. Aqueous surface chemistry of oxides and complex oxide minerals Isoelectric point and zero point of charge, p. 121-160. In R.F. Gould (ed.) Equilibrium concepts in natural water systems. Vol. 67. Advances in Chemistry Series, ACS, Washington, DC. 

Ligands and metal complexes present in aqueous systems in contact with natural oxides can affect their dissolution either by promoting or inhibiting it. For example, some metal—EDTA complexes react with Fe2C>3 and dissolve it, producing [Fe(III)EDTA]. Other minerals like Co(III)OOH and Mn(III)OOH reductively dissolve by oxidizing ligands and metal complexes. Dissolution rates can... 

Phillips BL, Casey WH, Karlsson M (2000) Bonding and reactivity at oxide mineral surfaces from model aqueous complexes. Nature 404 379-382... 

The discovery, in the mid-eighties, of the remarkable activity of TS-1 as a catalyst for selective oxidations with aqueous H2O2 fostered the expectation that this is merely the progenitor of a whole family of redox molecular sieve catalysts with unique activities. However, the initial euphoria has slowly been tempered by the realization that framework substitution/attachment of redox metal ions in molecular sieves does not, in many cases, lead to a stable heterogeneous catalyst. Nevertheless, we expect that the considerable research effort in this area, and the related zeolite-encapsulated complexes, will lead to the development of synthetically usefril systems. In this context the development of chiral ship-in-a-bottle type catalysts for intrazeolitic asymmetric oxidation is an important goal. Such an achievement would certainly justify the appellation mineral enzyme . 

Davis JA, Gloor R (1981) Adsorption of dissolved organics in lake water by aluminum oxide. Effect of molecular weight. Environ Sci Technol 15 1223-1229 Davis JA, Kent DB (1990) Surface complexation modeling in aqueous geochemistry. Rev Mineral 23 177-260... 

Some naturally occurring mineral oxides exhibit a high degree of isomorphous substitution of metal ions. These complex oxides make the interpretation of the adsorption study very difficult, and a detailed pretreatment of the mineral is often required before any adsorption study. With inert nonaqueous solvents, the need for a detailed pretreatment of the mineral is substantially reduced. This can be explained from the fact that the protonation and deprotonation of the mineral surface in aqueous solutions must be controlled by adjusting the pH, while this adjustment is not necessary in most organic solutions due to the lack of smface protonation. On the other hand, the molecular behavior of many amphiphilic solute molecules in apolar... 

Chemical relaxation methods can be used to determine mechanisms of reactions of ions at the mineral/water interface. In this paper, a review of chemical relaxation studies of adsorption/desorption kinetics of inorganic ions at the metal oxide/aqueous interface is presented. Plausible mechanisms based on the triple layer surface complexation model are discussed. Relaxation kinetic studies of the intercalation/ deintercalation of organic and inorganic ions in layered, cage-structured, and channel-structured minerals are also reviewed. In the intercalation studies, plausible mechanisms based on ion-exchange and adsorption/desorption reactions are presented steric and chemical properties of the solute and interlayered compounds are shown to influence the reaction rates. We also discuss the elementary reaction steps which are important in the stereoselective and reactive properties of interlayered compounds. 

The large isotopic fractionations observed between oxidized and reduced forms of sulfur compounds and aqueous complexes require accurate appraisal of the effective cogeneticity of sulfur minerals utilized as geothermometric couples, and of their equilibrium condition, to avoid erroneous deductions. In fact, besides temperature, the isotopic composition of sulfur minerals is also affected by the bulk isotopic composition of the sulfur in the system (which is controlled... 

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