Luminescence Detection of Ag⁺ and Phosphate Ions by a Ruthenium(II) Complex‐Based Multianalyte Probe: A Combined Spectroscopic, Crystallographic, and Theoretical Approach

Abstract

A bis-heteroleptic Ru(II) complex, 1[PF 6 ] 2 , of substituted pyridyl-1,2,3-triazole ligand (L1) has been developed for the photoluminescence(PL) detection of phosphate (HP 2 O 7 3À /PPi) and Ag + ion in distilled CH 3 CN and mixed aqueous buffer (carbonate-bicarbonate buffer/CH 3 CN; v/v, 9.5 : 0.5; 0.1 M; pH 10.6) at two different wavelengths, respectively. The multianalyte probe, 1[PF 6 ] 2 showed significant PL enhancement in the presence of H 2 PO 4 À , PPi, and Ag + with low detection limits of 0.48 μM, 0.43 μM, and 0.46 μM, respectively. The PL enhancement with phosphate ions is due to the triazole CÀ H•••anion H-bonding interaction that has been supported by 1 H NMR titration (for PPi) and single-crystal X-ray structure (for H 2 PO 4 À ). A unique Ag(I)-triazolide complex formation is responsible for the PL enhancement in Ag + ion detection. Triplet state TDDFT calculations were carried out to explain the PL enhancement of 1 • PPi and 1-Ag adducts. In 1-Ag, the L1 ligand becomes a better σ-donor as well as π-donor. Consequently, the 3 MLCT-3 MC energy gap is increased and the 1-Ag emits efficiently from the 3 MLCT state. The probe also shows low cytotoxicity against Hela cells and is used for intracellular Ag + imaging.

Cyclometalated iridium(iii) complex of a 1,2,3-triazole-based ligand for highly selective sensing of pyrophosphate ion

“…Consequently, nonradiative decay from the 3 MLCT excited state is inhibited, and PL is enhanced. 5,40 To demonstrate the high selectivity towards the H 2 P 2 O 7 2− PL spectra of 1[PF 6 ] (10 μM), various biorelevant species (30 μM) such as amino acids, ct-DNA, BSA protein and glutathione were checked. Except for H 2 P 2 O 7 2− , no significant PL enhancement was observed (Fig.…”

“…, imidazolium and thiazolium). 37–42 The C–H bond of 1,2,3-triazole can act as an amine bond surrogate unit for detecting anions due to the electronegativity of three nitrogen atoms of the ring in the triazole unit and an enormous dipole situated toward the triazole C–H bond exerted by the lone pair of nitrogen atoms. 43–46 Further, the acidity of triazole C–H proton strengthens on coordinating the triazole nitrogen with the metal center, thus promoting the binding ability of this C–H toward anions.…”

“…1). 5,39,40,45,58 b Herein, we reported a cyclometalated iridium( iii ) complex of new methylene bridges of benzimidazole-substituted 1,2,3-triazole methanol and its specificity towards H 2 P 2 O 7 2− over other competitive phosphates (Scheme 1). To the best of our knowledge, this is the first report of an iridium( iii ) complex-based probe for the luminescent light-up sensing of H 2 P 2 O 7 2− through multiple hydrogen-bonding interactions.…”

Achieving Selectivity for Phosphate over Pyrophosphate in Ethanol with Iron(III)-Based Fluorescent Probes

“…Such probes, however, do not work well with aqueous samples and are rarely selective for phosphate, including over pyrophosphate. 13 − 15 Direct coordination of phosphate is better suited for such applications since the metal ions are able to overcome the high hydration enthalpy of phosphate. 7 − 11 , 16 , 17 The requirements for lability and hardness have limited current studies to copper, zinc, and lanthanide complexes, 18 − 23 , 7 some of which have marked selectivity and affinity for phosphate.…”

Ruthenium(II) Polypyridine Complex-Based Aggregation-Induced Emission Luminogen for Rapid and Selective Detection of Phosgene in Solution and in the Gas Phase

“…Over the past decade, ruthenium­(II) polypyridine complexes have become preferred as sensors and probes, as photodynamic therapeutic (PDT) agents, and for bioimaging owing to their very rich photophysical and chemical properties, including intense visible excitation and emission, a large Stokes shift, high thermal and chemical stabilities, and very low cytotoxicity. − The emission properties of ruthenium­(II) polypyridyl complexes can be readily altered by varying the structural, electronic, and coordinating sites of polypyridyl ligands. − Also, the luminescence “off–on” flexibility can be attained by the alteration of the energy gap between non-emissive 3 MC and emissive 3 MLCT states after molecular interaction with analytes. − In recent years, a sizable number of Ru­(II) complex-based sensitive and specific luminescence probes have been developed for sensing cations, anions, and biorelevant species. − However, Ru­(II) complexes for specifically detecting CWAs have rarely been reported …”