Metal complexes coordinative binding

Fig. 22.2 Schematic procedures for the synthesis of molecularly imprinted catalysts (a) with organic binding sites Right triangle, Filled circle, Filled square) (e.g., NH, NH, OH, and COOH) on the wall of a polymer matrix and (b) using a metal complex coordinating a template ligand...

Alkanes are extremely poor acids, but on analogy with H2 binding to metal complexes, coordination to highly electrophilic M greatly enhances the acidity of the C-H bond and promotes heterolytic cleavage. Soft electrophiles such as Pt" and Hg" are ideal because they bind CH4 and other alkanes transiently even in aqueous... 

Although binding modes are considerably different between transition metals, cations, anions, and even in the rarer case, neutral molecules, there are nonetheless striking similarities if a broader view of binding is considered. Some specific examples are shown in Fignre 2. In transition metal complexes, coordinate covalent bonds are formed... 

Figure 23 Organometallic compounds 20-22 that act as metal complex receptors binding anions through second-sphere coordination.

Metal-assisted enantioselective catalytic reactions are one of the most important areas in organic chemistry [1-3]. They require the appropriate design and the preparation of chiral transition metal complexes, a field also of major importance in modern synthetic chemistry. These complexes are selected on both their ability to catalyze a given reaction and their potential as asymmetric inducers. To fulfill the first function, it is absolutely required that the catalysts display accessible metal coordination sites where reactants can bind since activation would result from a direct interaction between the metal ion... 

The reduction of C02 can be driven electrochemically at metallic cathodes, however, it requires large overpotentials (<—1.5 V) and electrode poisoning often occurs.65 Those problems can be addressed by adding catalysts. Metal complexes are a priori good candidates as electrocatalysts. It is expected that their reduction will be accompanied by the appearance of a vacant coordination site able to bind C02 and thus activate its reduction in the metal coordination sphere.1... 

The nature of the target to be attacked by any drug obviously depends on the specific application. Many cytotoxic metal complexes target DNA because of its importance in replication and cell viability. Coordination compounds offer many binding modes to polynucleotides, including outer-sphere noncovalent binding, metal coordination to nucleobase and phosphate backbone... 

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