Luminescent sensor for copper(II) ion based on imine functionalized monometallic rhenium(I) complexes

Interplay between the Conformational Flexibility and Photoluminescent Properties of Mononuclear Pyridinophanecopper(I) Complexes

“…During the past decades, photoluminescent (PL) materials have been widely utilized as sensors, electroluminescent displays, and probes of biological systems. − Among these materials, d 6 and d 8 transition-metal complexes such as iridium­(III), ruthenium­(II), osmium­(II), rhenium­(I), and platinum­(II) are extensively used because of their stability, tunability, and high efficiencies. − Another important class of PL compounds contains d 10 coinage metals such as silver­(I), gold­(I), and copper­(I). − Among these compounds, copper­(I) complexes are of considerable interest because of their low price and availability as an alternative to more expensive precious metal-based PL materials. ,− Over the last several decades, a great variety of copper­(I) PL complexes have been developed that include copper clusters, halide-bridged complexes, mono- and polynuclear phosphine complexes, homo- or heteroleptic species with diimine-type ligands, and recently developed N-heterocyclic carbene and amide complexes. − A variety of strategies were developed to control the emissive properties of copper­(I) complexes, mostly based on variation of the supporting ligand electronic properties ,, or, in some cases, control of the configurational changes using the steric properties of the ligand. ,, However, one of the common problems that can limit the practical application of copper­(I) complexes is their lability in solution, leading to dissociation of polynuclear species or, in the case of heteroleptic mononuclear complexes, ligand dissociation and exchange. ,− …”

Phosphorescence “Turn‐On” Sensing of Anions by Rhenium(I) Schiff‐Base Complexes

“…Herein, we report on the use of four tricarbonylrhenium(I) complexes containing hydroxyl and imine group of 2,2’‐bipyridine ligands 1–4 where the ligand functions as the binding site and rhenium center acts as the signaling unit. In our earlier studies, we have shown that these compounds acted as optical sensors for sensing of cations ,. Now, the sensitivity and selectivity of 1–4 towards F – ions over other anions is found via deprotonation of the phenolic OH group with a 1:1 complex formation, as demonstrated by UV‐vis absorption, phosphorescence and 1 H NMR spectral titration analyses as well as naked eye detection.…”

“…In our earlier studies, we have shown that these compounds acted as optical sensors for sensing of cations. [66,67] Now, the sensitivity and selectivity of 1-4 towards Fions over other anions is found via deprotonation of the phenolic OH group with a 1:1 complex formation, as demonstrated by UV-vis absorption, phosphorescence and 1 H NMR spectral titration analyses as well as naked eye detection.…”

A novel imidazole‐derived Schiff base as selective and sensitive colorimetric chemosensor for fluorescent detection of Cu2+ in methanol with mixed aqueous medium

“…[ 54–56 ] SB alone in solution exhibits a low emission intensity of fluorescence, owing to the free isomerization of the azomethine bond. [ 57,58 ] Therefore, upon the injection of Cu 2+ into the solution of SB , the C═N isomerization is inhibited due to the coordination of Cu 2+ to ligand SB by involving the binding site of the ligand SB (N atom of azomethine and OH group). The injection of Cu 2+ makes the formed complex more rigid.…”

“…[54][55][56] SB alone in solution exhibits a low emission intensity of fluorescence, owing to the free isomerization of the azomethine bond. [57,58] F I G U R E 7 Effect of pH on the absorption intensity at 542 nm of SB in the presence of Cu 2+ (3 equiv.) in MeOH-H 2 O (7:3) solution…”