Tetrathiafulvalene diindolylquinoxaline: a dual signaling anion receptor with phosphate selectivity

Abstract

Incorporation of tetrathiafulvalene into the backbone of a known neutral phosphate receptor, diindolylquinoxaline, yields a dual optical-electrochemical chemosensor for dihydrogen phosphate that functions in dichloromethane. This system shows selectivity for dihydrogen phosphate over other small anions and can be used to detect the presence of this analyte via fluorescence quenching or cyclic voltammetry.

Binding Constants and Their Measurement

“…For a recent example, see for instance, the work of Sessler and coworkers on a tetrathiafulvalene diindolylquinoxaline receptor that binds to anions such as dihydrogen phosphate ( Figure 3). 17 If the guest is also absorbed at the wavelength of interest to us, we get (28).…”

“…Figure 6 A schematic explaining the microscopic (K 1A , K 1B , K 2A , and K 2B ) association constants involved in the stepwise formation of a 1 : 2 complex. 2 When the binding sites A and B are truly identical, we cannot distinguish between HG 1A B and HG 1AB and, hence, determine K 1A and K 1B (or K 2A and K 2B ) as the physical changes analogous to, for example, Y HG in (17) for sites A and B in HG are identical. We can, however, relate the binding constants K 1A , K 1B , K 2A , and K 2B to the overall stepwise constants K 1 and K 2 .…”

Alfred Werner’s expanded legacy: Anion and metal ion coordination in an unsymmetrical, octaamido cryptand

“…3b and c). While there are examples of H 2 PO 4 À chains within channels formed by a host matrix or between hosts [44,45], this H 2 PO 4 À -H 2 O chain motif threading through the macrocyclic skeletons is an interesting manifestation of the interplay of solvent and anion sheltered by the bicyclic host.…”

Pyrenyl-functionalized ferrocenes for multisignaling recognition of anions

“…The multiple-signaling systems, which allow anion detection via more than one read-out mode, could lower the likelihood of false positives. 5 Ferrocene is a well known electrochemical active unit because of its stable one electron reversible redox potential property and easy functionalization. Ferrocene-based receptors with different anion binding sites have been well documented, 6 in which a negative shift in the redox potential of the receptors upon the addition of target anions, and the complexation ability of the ligand can be switched on and off by varying the applied electrochemical potential.…”