Binding multiple phosphodiesters with a polyazacleft

Artificial Receptors for the Recognition of Phosphorylated Molecules

“…This series of receptors also allowed for the determination of the strength of interactions arising from individual hydrogen bond donors and acceptors in the host systems. 55,56 Both 120 and 121 are cleft-like systems that contain three hydrogen bond donation sites and one hydrogen bond acceptor site. These receptors were designed to be complementary to the three oxygen atoms and one acidic hydrogen atom of a tetrahedral phosphoric acid diester.…”

“…These effects were studied by the Anslyn group, who designed the polyammonium receptors 120 – 122 to determine the optimum binding cavity size and hydrogen-bonding arrangement for the complexation of phosphoric acid diesters. This series of receptors also allowed for the determination of the strength of interactions arising from individual hydrogen-bond donors and acceptors in the host systems. , Both 120 and 121 are cleftlike systems that contain three hydrogen-bond donation sites and one hydrogen-bond acceptor site. These receptors were designed to be complementary to the three oxygen atoms and one acidic hydrogen atom of a tetrahedral phosphoric acid diester.…”

“…This behavior has been manifested in some cases through the binding of phosphate aggregates by organic hosts. 55,56 More recently, Gale and co-workers reported anion-anion proton transfer between dihydrogenphosphate species in the presence of a high affinity phosphate receptor in mixed organic / aqueous media. 57 …”

“…This property can be exploited to impart selectivity for inorganic phosphate over other tetrahedral anions such as sulfate that are not protonated near neutral pH; however, the dual donor–acceptor nature of phosphate anions can also lead to anion–anion interactions in less polar media. This behavior has been manifested in some cases through the binding of phosphate aggregates by organic hosts. , More recently, Gale and co-workers reported anion–anion proton transfer between dihydrogen phosphate species in the presence of a high affinity phosphate receptor in mixed organic/aqueous media …”

Molecular recognition and indicator-displacement assays for phosphoesters

“…1,2 Therefore, the design and synthesis of receptors that have high selectivities and affinities for phosphate esters in aqueous media is a current goal of molecular recognition studies. Receptors functionalized with guanidinium groups, 3-8 polyaza groups, [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] amides, 28 and ureas (including thiourea) [29][30][31] have been found to have high affinities towards phosphate esters through multiple hydrogen bonding and ion-pairing interactions. However, most of the previously reported receptors either lack high affinities or have low selectivities towards these guest molecules in aqueous media at neutral pH.…”