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Miguel A Mateos-Timoneda

Publications and source records attributed to Miguel A Mateos-Timoneda.

6 recordsLinked to original sources
PubMed2007

Dynamic combinatorial libraries based on hydrogen-bonded molecular boxes.

This article describes two different types of dynamic combinatorial libraries of host and guest molecules. The first part of this article describes the encapsulation of alizarin trimer 2a3 by dynamic mixtures of up to twenty different self-assembled molecular receptors together with the amplification and selection of the best binder. Receptors (1a-d)3.(DEB)6 are formed by the self-assembly of six diethyl barbiturate (DEB) and calix[4]arene dimelamine derivatives 1a-d by using hydrogen bonds. The largest amplification factor (2.8) for a host assembly (1a3.(DEB)6) was observed after the addition of 2a to four-component library 1a(n).1b(3-n).(DEB)6 (n=0-3). Addition of 2a to twenty-component library 1a(n).1b(m).1c(o).1d(3-(n+m+o)).(DEB)6 (n, m, o=0-3; (n+m+o)<or=3) also showed amplification of receptor 1a3.(DEB)6. The second part of this article describes the complexation of libraries of different alizarin-like guest molecules (2a-d) and the self-assembled receptor 1a3.(DEB)6. This receptor is able to template the formation of the best-fitting guest trimer.

Anthraquinones↗
PubMed2006

Amplification of chirality in hydrogen-bonded tetrarosette helices.

The amplification of chirality in hydrogen-bonded tetrarosette assemblies under thermodynamic equilibrium is described. The extent of the chiral amplification obtained by means of "sergeants-and-soldiers" experiments depends only on the structure of the assembly and it is independent of the methodology used for the formation of the tetrarosette assemblies. The difference in free energy (deltaG(o)(M/P)) between the M- and P-diastereomeric helices is up to 40 times higher than for double rosette assemblies.

Journal Article↗
PubMed2005

Selective self-organization of guest molecules in self-assembled molecular boxes.

This article describes the synthesis and binding properties of highly selective noncovalent molecular receptors 1(3).(DEB)6 and 3(3).(DEB)6 for different hydroxyl functionalized anthraquinones 2. These receptors are formed by the self-assembly of three calix[4]arene dimelamine derivative molecules (1 or 3) and six diethylbarbiturate (DEB) molecules to give 1(3).(DEB)6 or 3(3).(DEB)6. Encapsulation of 2 occurs in a highly organized manner; that is, a noncovalent hydrogen-bonded trimer of 2 is formed within the hydrogen-bonded receptors 1(3).(DEB)6 and 3(3).(DEB)6. Both receptors 1(3).(DEB)6 and 3(3).(DEB)6 change conformation from staggered to eclipsed upon complexation to afford a better fit for the 2(3) trimer. The receptor selectivity toward different anthraquinone derivatives 2 has been studied using 1H NMR spectroscopy, X-ray crystallography, UV spectroscopy, and isothermal microcalorimetry (ITC). The pi-pi stacking between the electron-deficient center ring of the anthraquinone derivatives 2a-c and 2e-g and the relatively electron-poor melamine units of the receptor is the driving force for the encapsulation of the guest molecules. The selectivity of the hydrogen-bonded host for the anthraquinone derivatives is the result of steric interactions between the guest molecules and the calix[4]arene aromatic rings of the host.

Anthraquinones↗
PubMed2004

Supramolecular chirality of self-assembled systems in solution.

Self-assembly plays an important role in the formation of many (chiral) biological structures, such as DNA, alpha-helices or beta-sheets of proteins. This process, which is the main tool of Supramolecular Chemistry (i.e. the chemistry of the molecular assemblies and of the intermolecular bonds), starts to play a significant role in nanotechnology for the construction of functional synthetic structures of nanometer size. The control of chirality in synthetic self-assembled systems is very important for applications of these systems e.g. in molecular recognition or mimicking of the catalytic activity of enzymes. This tutorial review deals with the most representative contributions in the field of supramolecular chirality. Specifically, the discussion centers on several examples that represent the control over chirality for self-assembled systems in solution.

Crystallization↗