Polymer combinatorial libraries molecularly imprinted

To overcome the problem of their limited range of applicability and to extend the spectrum of application other than to the imprint molecule, molecularly imprinted polymer combinatorial libraries for multiple simultaneous chiral separations have been prepared [ 191 ], demonstrating that the ligand cross-reactivities of molecularly imprinted polymers can be beneficially employed for the simultaneous separation of different stereoisomeric structures. 

In another attempt, cyclopeptide SOs and SO libraries, respectively, for CE enan-tioseparations have been developed by combinatorial chemistry approaches [378,379], and recently also molecularly imprinted polymer combinatorial libraries have been prepared [ 191 ]. 

Ramstrom, O., Ye, L., Krook, M., Mosbach, K. Screening of a combinatorial steroid library using molecularly imprinted polymers Anal. Comm., 1998, 35, 9-11... 

El-Toufaili, F.A., Visnjevski, A., Briiggemann, O. Screening combinatorial libraries of molecularly imprinted polymer films casted on membranes in single-use membrane modules J. Chromatogr., B, 2004, 804, 135-139... 

Villoslada, F. N. Takeuchi, T., Multivariate analysis and experimental design in the screening of combinatorial libraries of molecular imprinted polymers, Bull. Chem. Soc. Jpn. 2005, 78, 1354-1361. 

This chapter aims to provide an update on the role of anions as templates. The review is divided in two main sections (a) anion-templated synthesis of assemblies linked together by irreversible bonds (or bonds that are inert under mild experimental conditions) (b) anion templates in systems where the bonds linking the components are reversible and lead to anion-controlled dynamic combinatorial libraries. Since some comprehensive reviews in the area of anion temptation have appeared over the past few years [5-7], this chapter will mainly focus on papers published recently and will aim to show the principles of anion temptation rather than being a comprehensive account of the literature. In addition, the scope of the chapter will be restricted to finite assemblies (molecular or supramolecular) and not polymeric (for a review on molecularly imprinted polymers using anions see Steinke s chapter in this volume). 

The use of anions as templating agents is discussed by Vilar. The chapter starts with a general overview of the area and a discussion of the applications of anion templates in organic and coordination chemistry. The second part of the chapter deals with examples where anions are employed as templates in dynamic combinatorial libraries. This approach promises to provide an efficient route for the synthesis of better and more selective anion receptors. The last chapter by Ewen and Steinke also deals with the use of anions as templates but in this case in the context of molecular imprinted polymers. The first half of the chapter provides an introduction into molecularly imprinted polymers and this is followed by a detailed discussion of examples where anionic species have been used to imprint this class of polymeric materials. 

Bowman, M. Allender, C. Heard, C. Brain, K. Molecularly imprinted polymers as selective sorbents for the preliminary screening of combinatorial libraries. J. Mater. Sci. and Eng. C-Biomi Mater. Sens. Syst. 1998, 25, 37-43. 

Examples of this technique are described for artificial receptors for the alkaloid yohimbine binding peptides obtained from a phage display library [57], for the steroid libraries related to lla-hydroxyprogesterone [58], corticosterone [58] (reported in Fig. 12), and cortisol [59]. A molecularly imprinted polymer working as a synthetic receptor for a series of chiral benzodiazepines [47], artificial receptors for the tricyclic antidepressant drug nortriptyline—obtained by covalent and noncovalent molecular imprinting and studied by capillary liquid chromatography with a simulated combinatorial library [60,61]—were also examined. 

Takeuchi and co-workers (18) coupled combinatorial techniques with molecular imprinted polymers to develop sensors for triazine herbicides. The library consisted of a 7 x 7 array containing different fractions of monomers methacrylic acid (MAA) and 2-(trifluoromethyl)acrylic acid (TFMAA) with constant concentrations of the imprint molecules ametryn or atrazine. After UV-initiated polymerization, the products from the sensor library were characterized by HPLC measurement of herbicide concentration. The receptor efficiency was observed to vary with monomer type the atrazine receptor efficiency increased with MAA composition and the ametryn receptor was enhanced by increased fractions of TFMAA. Although only monomer concentration was varied in the hbraries, the authors conclude that the CM synthetic approach would be usefiil in analyzing other variables such as solvent, cross-linking agent, and polymerization conditions to produce optimum molecularly imprinted polymer sensors. 

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