Adsorption of ligands

The effects on metal ion adsorption of ligands that can themselves adsorb strongly can be quite different from that described above. Many multi-atomic ligands can bond to oxide surfaces through atoms different from those they use to... 

Nanowires of hexagonal cobalt can be grown by the selective adsorption of ligands on all crystal faces except the faces that become the sides of the wires. 

The adsorption of ligands (anions and weak acids) on metal oxide (and silicate) surfaces can also be compared with complex formation reactions in solution, e.g.,... 

At low pH, where resorption reactions are minimal, the photodissolution process may be represented as a two-step process involving adsorption of ligand L to metal oxide surface sites followed by detachment of reduced metal ions that is, for an iron oxyhydroxide ... 

Specific adsorption of ligands can enhance or inhibit dissolution rates by altering the strength and lability of Me-0 lattice bonds. Salicylate, oxalate, and citrate promote the dissolution of alumina (40). In the presence of ligand (L) the dissolution rate becomes (7 ) , ... 

The simple adsorption of ligand to surface, binding to a secondary ligand, or ligand immobilization through a coordination complex can be classified as this type of immobilization. This technique can be subdivided as follow ... 

V. Kourilov and M. Steinitz, Magnetic-beads enzyme-linked immunosorbent assay verifies adsorption of ligand and epitope accessibility, Anal. Biochem., 311 (2002) 166-170. 

Figure 25 reinforces previous diagrams and considers in greater detail the forces involved in nanoparticle interaction with biological surfaces at close approach. Physical adsorption of ligands to the surface of nanoparticles or covalent attachment of ligands changes the nature of the primary surface and wUl influence each of the forces referred to here. 

The rate of release of Mn from a Mn(III/IV) oxide is a function of the concentration of reductant in solution and oxide. The data in Fig. 7-5 and 7-6 show that with increasing concentrations of oxide or p-methylphenol the rate of release of Mn increases. With sufficient time the rate plots are curved (Fig. 7-6) due to the consumption of Mn oxide, because the reductant was in excess (Stone, 1987). At lower reductant concentrations the reaction is first-order with respect to concentration of reductant added (Stone and Morgan, 1984 Stone, 1987). The reduction is pH dependent with the rate increasing at lower pH. This is not surprising because reduction reactions consume protons and the adsorption of ligands is pH dependent. 

Interfacial catalysis should be designed by using the knowledge of the interfacial adsorptivity of ligands and complexes, and their reactivity, which all depend on their molecular structure. 

During typical surface complex formation, or ligand exchange, the surface hydroxyl group on the hydrous oxide exchanges with a similar Lewis base electron pair donor in the solution. Adsorption of either protons or hydroxide ions is interpreted in terms of an acid-base reaction at the oxide surface, i.e., the surface hydroxyl group is either protonated or deprotonated. The adsorption of ligands (anions and weak acids) on a metal-oxide surface can also be compared with complex formation reactions in solution, e.g. ... 

A number of enzymes may form abortive complexes that are nonproductive forms of the enzyme. Such complexes appear as a result of the adsorption of ligands under conditions where the enzyme may not carry out its usual chemistiy. For example, the binding of NAD " and acetaldehyde to alcohol dehydrogenase leads to the formation of an enzyme-NAD -acetaldehyde complex, wWch cannot allow for hydrogen transfer because both ligands are already in their oxidized states. 

The adsorption of ligand accelerates the extraction (a positive catalytic effect) but the adsorption of the complex apparently suppresses the extraction rate (a negative catalytic effect). 

El + EhElh, and 2Eh + Ehh (the second energy level is doubly degenerated). However, to study the details of the response of this polymer to the adsorption of ligands, it is more convenient to view it as a combination of two subunits, each having two states L and H, and to assume that information is transmitted between the subunits through the interaction parameters Ea. ... 

Background. Self-assembled monolayers (SAMs) form by the spontaneous adsorption of ligands from solution onto e surface of a metal or metal oxide (2,5). 

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