Synthesis and study of three hydroxypyrazole-based ligands: A ratiometric fluorescent sensor for Zn(II)

Synthesis of Fluorescent 1,7-Dipyridyl-bis-pyrazolo[3,4-b:4′,3′-e]pyridines: Design of Reversible Chemosensors for Nanomolar Detection of Cu2+

“…9,10 The TICT phenomenon is responsible for this type of compounds having high fluorescence quantum yields, and also, ligands 6 can be successfully used as fluorescent probes of metal ions. 9−12,23 Compound 6b was used in further studies of the design of fluorescent probes of metal ions because this ligand displayed the strongest fluorescence intensity. Ethanol was selected as a solvent due to the fact that this is a green solvent, is easily accessible, has high miscibility in water, and is easy to handle; also, it was taken into account that the 4-phenyl group of 6b is not affected by ethanol (Figure 3).…”

“…These compounds are novel tridentate ligands, whose synthesis proceeds by a three-step sequence under microwave starting from 2-chloropyridine ( 1 ). Ligands 6a – 6e contain a fused tricyclic structure that is dialkyl- and triaryl-substituted and also have three pyridine nitrogen atoms (CN:) suitably situated to achieve the formation of chelates. ,− ,, Thus, we have hypothesized that PBPs 6a – 6e have the necessary features for their use in the detection of metal ions through the fluorescence quenching process based on TICT mechanisms (Scheme b). − , In this work, compounds 6a – 6e showed a high fluorescence emission in different solvents and large Stokes shifts due to the TICT process being favored. In addition, the presence of a 2-pyridyl group at positions 1 and 7 of the bis-pyrazolopyridinic core has not yet been reported.…”

“…Ligands 6a – 6e contain a fused tricyclic structure that is dialkyl- and triaryl-substituted and also have three pyridine nitrogen atoms (C=N:) suitably situated to achieve the formation of chelates. 14,17−20,22a,23 Thus, we have hypothesized that PBPs 6a – 6e have the necessary features for their use in the detection of metal ions through the fluorescence quenching process based on TICT mechanisms (Scheme 1b). 8−10,12 In this work, compounds 6a – 6e showed a high fluorescence emission in different solvents and large Stokes shifts due to the TICT process being favored.…”

Idiosyncatic recognition of Zn2+ and CN− using pyrazolyl-hydroxy-coumarin scaffold and live cell imaging: depiction of luminescent Zn(ii)-metallocryptand

“…36 Pyrazolyl derivatives efficiently serve the purpose of colorimetric as well as fluorometric Zn 2+ sensors. 37,38 Thus, it is important to design analytical methods for the efficient, sensitive, selective, nontoxic, and cheap detection of Zn 2+ at the cellular level.…”

Synthesis, structure and bioactivity of Ni2+ and Cu2+ acylhydrazone complexes

“…Transition-metal complexes generated from multidentate N,O-donor ligands play an important role in the field of gas storage and separation (Yang & Xu, 2017), redox-active catalysis (Singh et al, 2018), biological systems (Gandhimathi et al, 2017;Xu et al, 2015) and fluorescent sensors (Formica et al, 2018;Sie et al, 2018). The organic ligands and the coordination mode of metal ions are considered to be the most important factors that affect the structures and properties of metal complexes (Bai et al, 2012).…”