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Complexes surface

The intennediate species Fe(OFi) and FeOFi can be regarded as constituting tire activated surface complex. The rate constant for fonnation and decay of tlris complex, k, can be written as... [Pg.2718]

Adsorption of Metal Ions and Ligands. The sohd—solution interface is of greatest importance in regulating the concentration of aquatic solutes and pollutants. Suspended inorganic and organic particles and biomass, sediments, soils, and minerals, eg, in aquifers and infiltration systems, act as adsorbents. The reactions occurring at interfaces can be described with the help of surface-chemical theories (surface complex formation) (25). The adsorption of polar substances, eg, metal cations, M, anions. A, and weak acids, HA, on hydrous oxide, clay, or organically coated surfaces may be described in terms of surface-coordination reactions ... [Pg.218]

Theories of the oxidation of tantalum in the presence of suboxide have been developed by Stringer. By means of single-crystal studies he has been able to show that a rate anisotropy stems from the orientation of the suboxide which is precipitated in the form of thin plates. Their influence on the oxidation rate is least when they lie parallel to the metal interface, since the stresses set up by their oxidation to the pentoxide are most easily accommodated. By contrast, when the plates are at 45° to the surface, complex stresses are established which create characteristic chevron markings and cracks in the oxide. The cracks in this case follow lines of pores generated by oxidation of the plates. This behaviour is also found with niobium, but surprisingly, these pores are not formed when Ta-Nb alloys are oxidised, and the rate anisotropy disappears. However, the rate remains linear it seems that this is another case in which molecular oxygen travels by sub-microscopic routes. [Pg.285]

The first step in the reaction is adsorption of Pronto the catalyst surface. Complexation between catalyst and alkene then occurs as a vacant orbital on the metal interacts with the filled alkene tt orbital. In the final steps, hydrogen is inserted into the double bond and the saturated product diffuses away from the catalyst (Figure 7.7). The stereochemistry of hydrogenation is syn because both hydrogens add to the double bond from the same catalyst surface. [Pg.230]

The surface of carbonaceous materials contains numerous chemical complexes that are formed during the manufacturing step by oxidation or introduced during post-treatment. The surface complexes are typically chemisorbed oxygen groups such as carbonyl, carboxyl, lactone, quinone, and phenol (see Fig. 3). [Pg.234]

The availability of organic ligands in the surface complexes obtained by the reaction of organometallic compounds with supports allows us to consider two possibilities of the initiation process (1) the monomer insertion into the organic ligand-metal bond (bensyl, allyl, etc.) (9a) ... [Pg.190]

Some data allow the realization of the second possibility to be proposed (8, 140) at least in the case of catalysts formed with the use of 7r-allylic compounds of chromium. In the reaction of Cr(7r-C3H3)2 with the Si02 surface, complexes are formed that may have vacant coordination sites... [Pg.190]

The interpretation of data on the change of Kp as a result of the reduction treatment of the chromium oxide catalyst (97) is hindered by the absence of precise data on the composition of the surface complexes being formed. [Pg.208]

The following assumptions are made (i) the activated complexes are in equilibrium with the reactants, (ii) the energy of a molecule is not altered when an activated complex is substituted for a nearest neighbour, and (iii) the products do not affect the course of reaction, except to define a boundary in surface processes. The various cases can be recognized from the magnitude of the pre-exponential term and calculated values [515] are summarized in Table 7. Low values of A indicate a tight surface complex whereas higher values are associated with a looser or mobile complex. [Pg.94]

Fig. 15-4 Analogy between dissolved ligands and adsorbents (surface-bound ligands) (a) surface acid-base reactions (b) surface complexation of free metals (c) formation of "mixed-ligand" surface complexes. Fig. 15-4 Analogy between dissolved ligands and adsorbents (surface-bound ligands) (a) surface acid-base reactions (b) surface complexation of free metals (c) formation of "mixed-ligand" surface complexes.
An XPS Investigation of iron Fischer-Tropsch catalysts before and after exposure to realistic reaction conditions is reported. The iron catalyst used in the study was a moderate surface area (15M /g) iron powder with and without 0.6 wt.% K2CO3. Upon reduction, surface oxide on the fresh catalyst is converted to metallic iron and the K2CO3 promoter decomposes into a potassium-oxygen surface complex. Under reaction conditions, the iron catalyst is converted to iron carbide and surface carbon deposition occurs. The nature of this carbon deposit is highly dependent on reaction conditions and the presence of surface alkali. [Pg.124]

Yet, mass balance analysis should be checked thoroughly since there can be some deviations/exceptions depending on the support and the metal. For instance, while the reaction of [Zr(CH2fBu)4] with Si02-(5oo) generates a monosiloxy species, its reaction with a MCM-41 material partially dehydroxylated at 500 °C yields a bissiloxy surface complex [21], and the reaction... [Pg.155]

One key aspect of SOMC is the determination of the structure of surface complexes at a molecular level one of the reasons being that our goal is to assess structure-activity relationships in heterogeneous catalysis, which requires a firm characterization of active sites or more exactly active site precursors. While elemental analysis is an essential first step to understand how the organometallic complex reacts with the support, it is necessary to gather spectroscopic data in order to understand what are the ligands and... [Pg.161]


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Actinides 534 surface complexes

Activated carbon surface oxygen complexes

Activated complex theory potential energy surfaces

Activated surface complex

Active sites surface complexes

Adsorption and reaction complexes on the catalytic surface

Adsorption from electrolyte solutions Surface complexation models

Adsorption isotherms surface oxygen complexes

Adsorption processes, surface complexation

Adsorption processes, surface complexation mechanism

Adsorption surface complexation models

Advanced Design of Catalyst Surfaces with Metal Complexes for Selective Catalysis

Amphoteric surface with complexation

Amphoteric surface without complexation

Aqueous surface chemistry of oxides and complex oxide minerals

Aqueous versus surface complexes

Arsenic surface complexation reactions

Assembled Monolayers of Metal Complexes on Single-Crystal Surfaces

Bidentate surface complexes

Bidentate surface complexes inner-sphere

Binuclear surface complexes, effect

Calculations complex surface structures

Carbene complex, surface bounded

Carbon electrodes surface oxygen complexes

Carbon surfaces oxygen complexes

Carbonates, surface complex formation

Catalyst surface, complex

Catalyst surface, complex composition

Cationic surface complexes, interfacial

Charge amphoteric surface with complexation

Charge balances, triple-layer model surface complexes

Chemical complexity, surfaces

Chemical surface complexation models

Chemisorption surface complex

Cluster complexes analogy with surfaces

Competitive solution/surface complexation

Complex Surface Structures

Complex formation mineral surfaces

Complex oxide minerals, aqueous surface chemistry

Complex surface activity

Complex surface reactions

Complex surface topography, substrate

Complexation at surfaces

Complexation nonspecific surface

Complexity of solid surfaces and effects on contact angle

Constant-capacitance surface complexation

Constant-capacitance surface complexation model, applications

Contributions of diffuse layer sorption and surface complexation

Copper complexes chiral surfaces

Deficiencies of surface complexation

Deficiencies of surface complexation models

Diffuse layer model metal surface complexation constants

Effects Due to More Complex Potential-Energy Surfaces

Electrical interfacial layer surface complexation model

Electrodes surface complexation

Electrophoretic mobility surface complexes

Electrostatic sorption and surface complexation

Enantioselectivity as a function of the bond strength in intermediate surface complex

Exploring Complex Energy Surfaces

Goethite surface complex

Heterogeneous catalytic reactions surface complex, formation

In situ synthesis of luminescent complexes on amorphous modified silica surfaces

Inclusion Complexes Between Polymers and Cyclic Molecules Surface Activity

Infinite complex of surfaces

Inner-sphere complex surface charge

Inner-sphere surface complexes

Inner-spheric surface complex

Intermediate surface complexes

Kaolinite surface complex

Ligand exchange surface complex model

Ligand-exchange mechanism, inner-sphere surface complex formation

Mass action equation surface complexation calculations

Mass balance equation surface complexation calculations

Mechanism of Hydrosilylation Catalyzed by Surface versus Soluble Rhodium Siloxide Complexes

Metal complex/surface reactivity

Metal complexes surface density

Metal surface complexation constant

Metals surface complexation models

Methanol surface complexes

Models of surface complexation

Montmorillonite surface complex

Multinuclear surface complexes

Multinuclear surface complexes, mineral

Multisite surface complexation model

Nickel complexes chiral surfaces

Numerical solution surface complexation calculations

Outer-sphere complex surface charge density

Outer-sphere complexes, surface coordination

Outer-sphere surface complexes

Particle surface complex

Phosphate surface complex structures

Phyllosilicates surface complexes

Potential energy surface activated complex

Potential energy surface complexes

Potential energy surface intermediate complex

Potential surfaces—complexes with

Potential surfaces—complexes with intermolecular hydrogen

Preconcentration by Surface Complexation

Precursor complex formation oxide surface sites

Principle of Molecular Imprinting for Metal Complexes on Surfaces

Reactions Apparently Controlled by Surface Complexes

Residual function surface complexation calculations

Single-crystal surfaces, metal complexes

Solid-supported surface catalysis, metal complexes

Solid—solution interface, surface complexation

Solution-phase reactions, surface complexation models

Some more Complex Reaction Surfaces

Stoichiometry of surface complexes

Supported Metal Complexes—Molecular Analogues Bonded to Surfaces

Supported complexes comparison with surfaces

Surface Complex Formation with Metal Ions

Surface Complexation Models Statistical Mechanics

Surface Complexes in Carbons

Surface Complexes involving other Elements

Surface Lewis complexes

Surface activity, complex copolymers

Surface charge complexation model

Surface charge complexes

Surface charge density inner-sphere complex

Surface chelation, polypyridyl complexes

Surface chemistry Group 8 complexes

Surface chemistry chromium complexes

Surface chemistry manganese complexes

Surface chemistry molybdenum complexes

Surface chemistry tungsten complexes

Surface complex chromophore

Surface complex formation

Surface complex formation equilibria

Surface complex formation model

Surface complex formation photoredox reactions

Surface complex hydrolysis reaction

Surface complex model

Surface complex model activity coefficients

Surface complex oxidation

Surface complex oxygenation

Surface complex photolysis

Surface complex reactivity

Surface complex ternary

Surface complex triple-layer model

Surface complexation

Surface complexation

Surface complexation behavior

Surface complexation constant

Surface complexation constants predicting

Surface complexation effect

Surface complexation limit

Surface complexation model

Surface complexation model activity coefficients

Surface complexation model characteristics

Surface complexation model structure

Surface complexation modeling

Surface complexation models (SCMs

Surface complexation models Stem layer model

Surface complexation models Stem model

Surface complexation models acid-base properties

Surface complexation models adsorption experiments

Surface complexation models approximation

Surface complexation models capacitance values

Surface complexation models continuous heterogeneity

Surface complexation models diffuse layer model

Surface complexation models electrolyte-binding constants

Surface complexation models equation

Surface complexation models external surfaces

Surface complexation models interactions

Surface complexation models microscopic data

Surface complexation models modeling procedures, consistencies

Surface complexation models oxide-solution interface

Surface complexation models particle geometry

Surface complexation models particle morphology

Surface complexation models proton uptake

Surface complexation models protonation mechanism

Surface complexation models reactions

Surface complexation models site concentration

Surface complexation models solid-solution interface

Surface complexation models temperature dependence

Surface complexation models titrations

Surface complexation phenomena related

Surface complexation photoredox reaction

Surface complexation reactions

Surface complexes energies

Surface complexes site definition

Surface complexes, lithiated carbons

Surface confined complex

Surface films of sterols and other substances with complex ring systems

Surface functional groups oxygen complexes

Surface interaction, effect complexes

Surface models Complex surfaces

Surface organometallic complexes

Surface organometallic complexes formation

Surface oxygen complexes

Surface oxygen complexes carbon surfaces

Surface oxygen complexes chemical analysis

Surface oxygen complexes desorption

Surface potential complexation model

Surface rhodium siloxide complex

Surface rhodium siloxide complex hydrosilylation

Surface sites complex formation

Surface tension complexes

Surface-bound affinity complex

Surface-located inner coordination sphere complexes

Surface-metal-ligand complexes

The Structure of Surface Complexation Models

Triatomic complex potential energy surface

Unsaturated hydrocarbons surface complexes

Vermiculite inner-sphere surface complex

Vermiculite surface complex

Well-Defined Surface Rhodium Siloxide Complexes and Their Application to Catalysis

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