Selective binding of (thio)sulfate and phosphate in water by quaternary ammonium functionalized oligo-ureas

Abstract

Functionalization of oligo-ureas with quaternary ammonium groups leads to water soluble receptors for selective binding of adenosine phosphates in water.

A Neutral Porous Organic Polymer Host for the Recognition of Anionic Dyes in Water

“…Urea is commonly used as a neutral recognition motif that effectively provides two parallel hydrogen bond donors for binding oxyanions but primarily in organic solvents or mixtures of organic solvents and water. 45,[70][71][72][73][74][75][76][77][78][79] However, through encapsulation in a POP, here we show in a rare instance that urea is capable of hydrogen bonding with anionic guests in pure water. 70,80 As a proof-of-concept, we tested the ability of Urea-POP-1 to recognize organic dyes through adsorption assays that contain phosphonate (R-PO3 2-), sulfonate (R-SO3 -), and carboxylate (R-COO -) anions.…”

“…We next tested if the urea sidechains in Urea-POP-1 could be used for the recognition of anionic guests in water. To do so, we selected dyes containing oxyanions commonly known to interact with urea-based hosts, 70,71,77 including phosphonate (AMP, ATP, and FMN), sulfonate (methyl orange, Lucifer Yellow CH, and bromophenol blue), and carboxylate (Rhodamine B, methyl red, Alizarin Yellow G, and fluorescein) anions (Figure 3). Recognition of the dyes was evaluated through adsorption assays in water as monitored by absorption or fluorescence spectroscopy with varying concentrations of Urea-POP-1 and Methyl-POP-1, with the latter serving as a control for hydrophobic interactions (Figure 3).…”

A neutral porous organic polymer host for the recognition of anionic dyes in water

“…We next tested if the urea sidechains in Urea-POP-1 could be used for the recognition of anionic guests in water. To do so, we selected dyes containing oxyanions commonly known to interact with urea-based hosts, 69,74,78 including phosphonate (adenosine 5 0 -monophosphate or AMP, adenosine 5 0 -triphosphate or ATP, and riboavin 5 0 -monophosphate or FMN), sulfonate (methyl orange, Lucifer Yellow CH, and bromophenol blue), and carboxylate anions (Rhodamine B, methyl red, Alizarin Yellow G, and uorescein) ( Fig. 3).…”

“…68 Previous reports with urea containing hosts were carried out primarily in organic solvents or mixtures of organic solvents and water with a limited of number examples in pure water. [69][70][71][72][73][74][75][76][77][78][79][80] We hypothesized that a densely packed array of conned urea sidechains, in combination with the hydrophobic microenvironment provided by the POP could cooperatively promote anion desolvation and recognition in water. As a proof-of-concept, we have systematically tested the ability of Urea-POP-1 as a supramolecular host to recognize organic dyes that contain phosphonate (R-PO 3 2À ), sulfonate (R-SO 3 À ), and carboxylate (R-COO À ) anions through adsorption assays.…”

When Molecules Meet in Water‐Recent Contributions of Supramolecular Chemistry to the Understanding of Molecular Recognition Processes in Water

“…In the case of 21, large positive entropic terms of complex formation suggest that binding benefits from the release of water molecules from the receptor cavity. [87] These and further examples [88][89][90][91][92][93] illustrate that ionic interactions in water contribute to the stability of host-guest complexes. The high stabilities observed for certain complexes, the pronounced exothermicities associated with complex formation, and some binding selectivities indicate, however, that other types of interactions, including those mediated by the solvent, also influence binding, sometimes even to a larger extent than salt bridge formation.…”