Selective complexation recognition

Fig. 11) form very strong and selective complexes with Fe or actinide and lanthanide ions (63,64) while a similar receptor with hard endocarboxyhc acid groups is efficient for hard and ions showing again responsibility of a charge density effect in the receptor—substrate recognition (65). Thus,... 

The complexation process is characterized by its thermodynamic and kinetic stability and selectivity, i.e. by the amount of energy and the amount of information brought into operation. Thus, conceptually, energy (interaction) and information are at the bottom of the recognition process of one chemical entity by another, and the design of molecular systems capable of forming stable and selective complexes becomes a problem in information storage and readout at the molecular level. 

Advances in biotechnology have been tremendous. There are many issues in biochemistry and biotechnology that have not yet been completely elucidated however, progress has been made. For example, antibiotics have evolved, the polymerase chain reaction has been developed, and DNA sequencing, genomics, proteomics, combinatorial synthesis, and selective complexation and recognition chemistry have all advanced. 

Natural macrocycles displaying antibiotic propenies are also very efficient in the recognition of alkali metal ions. For instance, valinomycin (5 in Fig, 3) gives a strong and selective complex in which a K+ ion is included in the macrocyclic cavity in octahedral environment of six carbonyl oxygens (Fig. 4). 

Polyaza-, polythia-ligands. Recognition of transition metal ions. Replacing the oxygen sites with nitrogen or sulphur yields macrocycles and cryptands that show marked preference for transition metal ions and may also allow highly selective complexation of toxic heavy metals such as cadmium, lead and mercury [2.41-2.44, A.14]. 

On these bases, proteins like human serum albumin (HSA) and avidin (Av) have been labelled with such complexes. This yields bioconjugates that are strongly luminescent and can be used for recognition purposes [79]. In Table 10 are listed luminescence properties of some selected complexes and related bioconjugates [79]. 

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