Anion sensing by Phenazine-based urea/thiourea receptors

Phenazines as chemosensors of solution analytes and as sensitizers in organic photovoltaics

“…reported synthesis of a colorimetric receptor possessing bis-urea appended phenazine and its application in sensing and differentiation between fluoride, acetate and dihydrogen phosphate anions. 7 The molecule was synthesized (Scheme 8) by refluxing a DMF/THF solution of 2,3-diamino phenazine with phenyl isocyanate. While the urea motif served as the anion receptor, the phenazine portion was the chromogenic signaling subunit exhibiting the optical spectral changes sensitive to the analyte anion.…”

“…5 In course of DNA-intercalation, phenazine absorption and fluorescence could vary substantially depending on the type of nucleotides present in a binding site. Fluorescent phenazines have also been used as selective cations 6 and anion binding agents 7 due to their optical spectral alterations and colorimetric changes upon analyte binding, whereby the latter would aid in the 'naked-eye' detection. These compounds are capable of intramolecular charge transfer (ICT), modulation of which by the analyte binding leads to the signal amplification and or ratiometric spectral shifts.…”

Theoretical Study of Intramolecular Charge Transfer Turn-off Switching of N-(4-Dimethylaminobenzoyl) Thiourea Induced by Anion Recognition

“…The fluorescent chemical sensor, N-(4-Dimethylaminobenzoyl)thiourea (DMABTU; Chart 1) that has been reported by Wu et al [1], has two emission wavelengths at ca. 500 nm (stronger) and ca.…”

“…The development of colorimetric and fluorescence chemical sensors that have a function of in situ selective sensing of biologically or environmentally important anions is one of the significant issues in host-guest chemistry, and a large number of studies have been carried out in the field [1][2][3][4][5]. In these anion sensors, urea/thiourea groups have been often employed as an anion receipting unit.…”

Synthesis of Chemosensor Based on Pyrene and Study for Its Sensing Properties Toward Fluoride Ion

“…In addition, Benesi-Hildebrand method 15,16) was also progressing as shown in Figure 5 Depending on the above results, the binding mechanism of chemosensor + F -structure was proposed in Scheme 2. The structure referred to reported papers [17][18][19][20][21] . In structure of chemosensor, the NHfragments can be involved to bind the F -by hydrogen bonding donors.…”