Design of ligands

As in the case of organoaluminium compounds, unusual stereochemistries can be imposed by suitable design of ligands. Thus, reaction of GaCh with 3,3, 3"-nitrilotris(propylmagnesium... 

Geometric isomers for square and octahedral coordination with two different ligands. Top right designation of ligand positions in an octahedral complex... 

In an elegant approach, Comba and co-workers initiated molecular-mechanics-based models that allow the rational design of ligand systems which are able to stabilize copper-dioxygen compounds. As a part of this investigation, complexes (241) (r = 0.12),223 (242) (r = 0.31),224 and (243) (r = 0.85)224 were synthesized and the reactivity of copper(I) complexes (Section 6.6.4.2.2(iv)) with dioxygen was investigated. 

This review will focus on processes which depend on the selection or design of ligands to enhance the effectiveness of the four unit operations listed above. In general, the application of such ligands relates to equilibria involving distribution of a metal between two phases. 

In a review on the design of ligands for selective complexation of metal ions in aqueous media and a book on the principles underlying stability constants and on the design of metal complexes for various medical applications iron complexes and their solution chemistry take their appropriate place. 

Since the central topic of the present chapter is the design of ligands for the selective complexation of alkali and alkaline-earth cations, we shall first consider the most general features of such processes. 

Following the above analysis and using some simple considerations, the following proposals concerning the design of ligand topology may be made ... 

Top right designation of ligand positions in an octahedral complex... 

Several studies on models have been reported, both on the binding of a range of metals to apometallothionein and the design of ligands, particularly with Cys-X-Cys and Cys-X-Y-Cys arrangements as found for metallothionein.1163,1164 All metal derivatives appear to bind in metal-thiolate clusters.1149 Platinum has also been found bound to metallothionein in rat tissues following treatment with cisplatin and the trans isomer.1165... 

The ability to predict structures can be important in the design of ligands. Chapter 7 deals with stereoselectivities predicted and interpreted by molecular mechanics. 

Bunnelle WH, Dart MJ, Schrimpf MR. Design of ligands for the nicotinic acetylcholine receptors ... 

Design of ligand-bound macromolecules for receptor-mediated transport. 

Design of Ligand-Based Targeting Drug Delivery Systems... 

Future work can be expected to involve more detailed design of ligands and metal centers with the intention of providing metal complexes that are especially sensitive to changes in viscosity and polarity within different types of monomer/polymer environments. In taking this type of approach, it will be possible to more specifically tailor the emission properties of the probe molecules to applications in a variety of polymerization processes. 

The sapphyrin unit connected to natural ionophore lasalocid [78] has been used for the design of ligand 48. Membrane transport was measured for this ligand using a traditional U-tube arrangement. It was found that the ligand is able to transport amino acids in their zwitterionic form with a preference for the L-enantiomer of Phe. 

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