Ruthenium ion exchanged

Int. J. Mol. Sci. 2010, 11, 3334-3348; doi:10.3390/ijms11093334
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International Journal of

Molecular Sciences
ISSN 1422-0067 www.mdpi.com/journal/ijms Review

Recognition of Chiral Carboxylic Anions by Artificial Receptors
Pape Sylla Dieng and Claude Sirlin * Institut de Chimie UMR7177 CNRS, Université de Strasbourg, 4 Rue Blaise Pascal, 67070 Strasbourg, France; E-Mail: [e-mail] * Author to whom correspondence should be addressed; E-Mail: [e-mail] Received: 30 July 2010; in revised form: 19 August 2010 / Accepted: 12 September 2010 / Published: 15 September 2010

Abstract: Many carboxylic molecules, ranging from drugs to flavors and fragrances, contain chiral centers. As a consequence, research has been carried out in order to design and synthesize artificial receptors for carboxylic anions. Many problems have to be solved for binding anions. The results obtained in the binding of carboxylic anions by guanidine, secondary ammonium and metal-center have been selected. The last part of this review focuses on chiral recognition of carboxylic anions by organic and metal-based chiral receptors. Keywords: molecular recognition; anion recognition; chiral carboxylic anions recognition

1. Introduction Anions are ubiquitous in the natural world. Chloride is present in large amounts in the oceans; nitrate and sulfate are found in acid rain; carbonates are the key constituents of mineral materials. Anions are also critical for maintenance of life; they are involved in recognition, transport and transformation in almost every biochemical operation. For instance, anions are present in roughly 70% of all enzymatic sites, play structural roles in many proteins, and are critical for the storage of genetic information (DNA and RNA are poly-anions). Anions are also involved in activating signal transduction pathways, maintaining cell volume, and in the production of electric signals. X-ray structures have been solved allowing