Two novel multifunctional chemical sensor Mn-LMOF, namely, [Mn2(TPPE)(ndc)2(H2O)]n (LMOF-1) and [Mn2(TPPE)(oba)2]n (LMOF-2) were solvothermally synthesized by introducing an AIE luminogens (AIEgens) ligand, 1,1,2,2-tetra[4-(pyridin-4-yl)phenyl]ethylene(TPPE), and analyzed by single crystal X-ray diffraction, thermogravimetric and powder X-ray diffraction and other methods. LMOF-1 and LMOF-2 have high stability and strong luminescence properties in solutions. The sensing experiments testify that LMOF-1 can be used as a selectively sensor for Al3+, with the limit of detection is 1.83 × 10−5 M. And LMOF-1 and LMOF-2 can identify Fe3+, CrO42− and Cr2O72− ions in aqueous solution, and LMOF-1 has a higher Ksv for all three ions than LMOF-2.

Herein, we report a Cu(II) complex {[CuII(HL)(H2O)2]Cl} of a benzoylhydrazone Schiff base ligand (4-((2-benzoylhydrazineylidene)methyl)-3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-1-ium chloride) (H2L). The molar conductance in solution, magnetic susceptibility, ESI-MS and EPR spectroscopy have been performed to justify the structure of the complex. The solid-state structure of the complex has also been solved by single crystal X-ray diffractometry. Cu(II) centre is penta-coordinated with imine-N, phenoxide-O and deprotonated amide-O donor of the ligand and two H2O molecules occupying the coordination sphere forming a distorted square pyramidal geometry (τ = 0.32). We have studied the anion sensing property of the complex by monitoring the changes in the UV–Vis and fluorescence spectra of the complex in aqueous Tris-HCl buffer medium with incremental addition of various anions of tetrabutylammonium salt. The complex shows appreciable sensitivity toward sulphide ion, among various other anions, with association constant (Kb) for binding of the complex with S2− and lowest detection limit (L.O.D) value of 6.87 × 104 M−1 and 6.9 × 10−7 M, respectively. Thus, the complex can be used as an efficient S2− probe. The mechanism of sensing is found to be displacement of the fluorescent ligand from the Cu(II) complex by the sulphide ion.

In this study, 1-ferrocenyl-3-(2-hydroxyphenyl) allyl ketone (probe A) was synthesized using a solvent-free method in conjunction with solid-phase grinding and employed as a probe for the detection of tryptophan (Trp). The probe exhibits selective recognition of Trp as evidenced by UV–Vis and fluorescence spectra. In complex scenarios, the probe’s recognition of Trp remains unaffected by both the presence of interfering substances and the duration of exposure. A pH range of 8 to 12 is found to be optimal for the detection of Trp. Job’s curve analysis revealed that the binding ratio between the probe and Trp is 1:1. Based on the Benesi-Hildebrand equation, the binding constant for the interaction between probe A and Trp is calculated to be 1.5 × 107 M−1. The detection limit for Trp was determined to be 9.55 × 10−5 M. The sensing mechanism of the probe for Trp was elucidated through 1H NMR and FT-IR analyses.

Carbanions are typically highly reactive species but can be efficiently stabilized to even function as stable weakly coordinating anions (WCA). We now report on the coordination chemistry of the recently introduced allyl anion 1, stabilized by ArF (ArF = 3,5-bis(trifluoromethyl)phenyl), triflyl substituents, with various s-block metals. A systematic crystallographic study on the s-block metal salts (Li-Cs, Ca) showed that the alkali metals have minimal impact on the anion, as indicated by the similar structural properties compared to the phosphonium salt of 1. In contrast, the calcium complex showed a slightly more pronounced distortion of the allyl symmetry due to stronger Ca–O interactions with the triflyl group. Additionally, the significance of the allyl moiety in stabilizing the carbanionic charge in 1 was demonstrated by comparing the structural parameters and charge distribution with those of an analogous C1-anion. Overall, these studies confirm the enhanced stability of 1 and its weak coordination tendency