Selective recognition and extraction of KBr via cooperative interactions with a urea functionalized crown ether dual-host

Abstract

Selective solid-liquid extraction of KBr is demonstrated for the first time with a crown ether based pentafluorophenyl urea functionalized dual-host receptor. (1)H-NMR and ITC studies have been carried out to illustrate the effect of cooperativity towards the recognition of alkali metal salts.

A Bis(Boronic Ester)-Based Fluorogenic and Chromogenic Sensor for F-and Cu2+

“…[8][9][10][11][12][13][14][15][16][17][18] On the other hand, various organic compounds containing different hydrogen bonding donor functionalities such as urea, thiourea, amide, pyrrole andimidazole have widely been used for the detection of fluoride. [2][3][4][5][6][7][8][9][10][22][23][24][25][26][27][28][29][30] Although a number of heteroditopic molecules have been designed for the detection of either anion or cation (alkali, alkaline earth and transition metals), either separately or as ion-pairs, [33][34][35][36][37][38][39][40][41][42][43] simultaneous detection of both Cu 2 + and Fby a single receptor is only a few in the literature. [44][45][46][47] Both boronic acids and boronic esters are potential chemosensors for anions because of Lewis acid-base interaction (boron is electron deficient).…”

“…On the other hand, various organic compounds containing different hydrogen bonding donor functionalities such as urea, thiourea, amide, pyrrole andimidazole have widely been used for the detection of fluoride ,. Although a number of heteroditopic molecules have been designed for the detection of either anion or cation (alkali, alkaline earth and transition metals), either separately or as ion‐pairs, simultaneous detection of both Cu 2+ and F – by a single receptor is only a few in the literature …”

From Heteroditopic to Multitopic Receptors for Ion‐Pair Recognition: Advances in Receptor Design and Applications

“…Importantly, the lattice energy of the target ion-pair is a determining factor in solid-liquid extraction, whereas receptor-ion-pair binding competes with hydration energies in aqueous liquid-organic phase liquid extraction. [41] The rational design of a salt extraction/solubilisation agent for a target ion-pair is challenging since the ion-pair binding affinity alone cannot be used to predict the extraction efficiency. For example, Romański and Piatek reported receptor 31 ( Figure 19) extracts sodium nitrate in solid-liquid extraction experiments more efficiently than sodium acetate and chloride even though this ion-pair was bound the most weakly of the sodium salts in ion-pair binding studies.…”

Enhancement of Ion Pairing of Sr(II) and Ba(II) Salts by a Tritopic Ion‐Pair Receptor in Solution

“…Additionally, the modification of the recognition sites allows for fine-tuning the selectivity, thus, a plethora of receptors has been designed for efficient binding of alkali metal (MX) and tetraalkylammonium salts (R 4 NX). As such, IP receptors have emerged as potential candidates for numerous applications, such as salt extraction, [12][13][14][15][16][17] transmembrane transport, [18][19][20][21][22][23] and catalysis. [24,25] The ability to tailor cationic and anionic binding sites also enables the design of multitopic receptors.…”