Combinatorial chemistry general principle

In principle, it is conceivable that ionic liquids may be used for the immobihza-tion of catalysts in a parallel set-up, but so far this has not been employed in combinatorial chemistry. This is probably due to the high costs of ionic liquids, the general problems associated with Uquid-hquid separations in parallel work-up, and the fact that this is a relatively new technology. 

In the context of combinatorial chemistry, as well as in natural products chemistry, it is quite possible that the analyte of interest is not contained in spectrum databases. In recent years, the use of structural (or compound) databases for structure elucidation has increased due to the evolution of web-based services such as PubChem [218] and ChemSpider [259], with approximately 26 million entries each. These databases do not generally contain spectra (there are some exceptions) and as such only provide information about compounds that have been documented to exist. Although this is a smaller subset of possible structures for a given molecular formula than generating all mathematically possible structures, the same principles apply to determining the correct one as for generated structrues, without the guarantee that the correct struc-... 

Nicolaou, K.C. et al., Natural product-like combinatorial libraries based on privileged structures. 1. General principles and solid-phase synthesis of benzopyrans, J. Am. Chem. Soc., 122, 9939, 2000. Nicolaou, K.C. et al., Natural product-like combinatorial libraries based on privUeged structures. 2. Construction of a 10,000-membered benzopyran library by directed split-and-pool chemistry using NanoKans and optical encoding, J. Am. Chem. Soc., 122, 9954, 2000. 

Although this concept was only recently articulated as a general approach to the synthesis of chemical species exhibiting molecular recognition capabilities, many of the principles and practices that characterize DCC had been in place for several decades. DCC may be viewed as the intersection of two pre-edsting approaches to synthesis thermodynamically controlled templated synthesis and combinatorial chemistry. 

Figure 1. General principle of the combinatorial approach a parameter library is produced by varying the tribological stress on a single sample depending on the lateral e.g. radial (R) and angular (> position on the disk. The tribological information acquired during or after the test (coef dent of friction, wear) and the spectroscopic information (chemistry of surface Im) from surface-analytical examination of the sample can...

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