Ein makrocyclisches Polyphenolat als Rezeptoranalogon für Cholin und verwandte Ammoniumverbindungen

Abstract

Die seit langem bekannte Kondensation von Resorcin mit Acetaldehyd ergibt das Tetraphenolat H (R=CH3. Diese napfförmige Wirtverbindung zeichnet sich durch cyclische Wasserstoffbrücken und delokalisierte negative Ladung, aus, was zu einer hohen Symmetrie und Stabilität und zu den höchsten bisher bekannten Bindungskonstanten für Methylammonium‐Ionen vom Cholintyp und ähnlichen Derivaten führt.

Counterion effect in SDS–calix[4]resorcinarene micelles

“…The insertion of polyanions with selective binding properties into DS micelles have been chosen as a way to make the counterion structure a crucial factor in clouding phenomenon of micellar systems. The amphiphilic calix[4]resorcinarenes with varied length of hydrophobic tails and charged groups on the upper rim exhibit both selective binding ability [26][27][28] and sufficient amphiphilicity to undergo self-aggregation [29][30][31] or to be compatible with micelles [32][33][34][35][36]. The present work continues our recent studies of receptor properties [33,34,36] and CP behavior of mixed calix[4]resorcinarenesurfactant micelles with nonionic TX-100, Brij-36, TX-450 and SDS as surfactants [35,36].…”

“…The deprotonation of phenolic groups of calix[4]resorcinarenes (H 8 L) in accordance with equilibrium (1) both in aqueous [26][27][28] and micellar solutions [30,31,33] produces four negative charges on the upper rim (Scheme 1), thus enhancing the calix[4]resorcinarene binding ability towards organic cations.…”

“…Calix[4]resorcinarenes with alkyl chains varying from methyl to undecyl are insoluble in water, but easily soluble in aqueous organic [26,27] or micellar solutions [33,34,36]. The deprotonation of phenolic groups of calix[4]resorcinarenes (H 8 L) in accordance with equilibrium (1) both in aqueous [26][27][28] and micellar solutions [30,31,33] produces four negative charges on the upper rim (Scheme 1), thus enhancing the calix[4]resorcinarene binding ability towards organic cations.…”

Experimental Evidence for Alkali Metal Cation−π Interactions

“…[7] In the realm of supramolecular chemistry, several research groups have reported cyclophanes, calixarenes, and other host molecules that bind quaternary amines in cavities having extensive π surfaces. Notable among these efforts are contributions by Collet, [8] Dougherty, [9] Lehn,[10] Mandolini, [11] Schneider, [12] Roelens, [13] Schwabacher, [14] and Shinkai. [15] These synthetic receptor molecules provided strong evidence that the ammonium cationϪπ interaction is a substantial force that may contribute significantly to molecular recognition.…”

Mass Spectrometric Investigation of Noncovalent Complexation between a Tetratosylated Resorcarene and Alkyl Ammonium Ions

“…Resorcarene complexation has been reported with alkali metal cations, [3] alcohols, [4] various nitrogen compounds, [5] sugars, [6] and steroids. [7] Mass spectrometry (MS) with a soft ionization technique, such as electrospray ionization (ESI), [8] is challenging the more traditional methods, such as X-ray diffraction methods [9,10] and NMR spectroscopy, [3a, 4, 7a, 11, 12] in studies of hostguest complexation.…”