Selektive Komplexierung von N-Alkylpyridiniumsalzen: NAD+-Erkennung in Wasser

Abstract

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Glycoluril‐Derived Molecular Clips are Potent and Selective Receptors for Cationic Dyes in Water

“…The importance of cation-π interactions in both designed and biological host•guest processes has been clearly delineated by Dougherty, [29] and has been invoked by Klaerner to explain the affinity of benzonorbornene derived clips toward NAD + . [24,25,27] An examination of Table 1 reveals that the best guests for host 1 are methylene blue and Azure A which are large, planar, delocalized aromatic monocations which can engage in cation-π interactions with 1 . The importance of cation-π interactions can be assessed by a comparison of the affinity of cationic methylene blue (K a = 3.92 × 10 7 M −1 ) with that of neutral methylene violet (K a = 5.76 × 10 4 M −1 ) which differ only in the exchange of an N + Me 2 for a C=O group.…”

“…K1 •NAD + , K a = 7100 M −1 ) with modest affinity. [25,27,28] The importance of cation-π interactions [29] in the recognition behavior of K1 was implicated. Given the propensity of molecular clips and tweezers to self-associate or dimerize, especially in water, the ability of 1 to act as a solubilizing agent was particularly surprising.…”

Anion assisted self-assembly of a Ni(II) complex into metallo-supramolecular network involving H-bonded synthons as nodes

“…While it is unlikely that microporous materials devised by coordination chemistry will be as robust as naturally occurring zeolites, these materials offer architectures and internal surface where the nature and size of the pore may be altered [17,18]. Beside these fundamental importances, non-covalent interactions play a key role in molecular self-organization and recognition in chemical, physical, and biological sciences [19][20][21].…”

“…It is noteworthy that a ''free or non-coordinated" anion can influence a framework by instigating a preferable supramolecular recognition because the metal-bound anion has a restricted stereoelectronic option of forming intermolecular interactions [20]. The transition-metal complexes of 1,2,4-triazoles have been employed in recent times in the construction of complex metal-organic architectures with diverse topological features and physical properties [23][24][25][26].…”

Nucleoside Sensing

“…Over the past decades, Klärner et al have created a large number of rigid molecular clips and tweezers, comprising an electron-rich cavity which is able to accomodate unpolar or cationic small guest molecules [5]. In a cooperation, we have recently rendered the parent molecular clip water-soluble by adorning the central benzene ring with methyl phosphonate functionalities and found efficient binding of cationic aromatic substrates such as NAD + (Figure 1) [6]. Now we discovered that neutral electron-deficient guests are also included inside the electron-rich cavity.…”