Newly designed and synthesized heterobimetallic [CuII–DyIII] salamo-like complex: structural characterization, DFT calculation, and fluorescent property

A novel bifunctional-group salamo-like multi-purpose dye probe based on ESIPT and RAHB effect: Distinction of cyanide and hydrazine through optical signal differential protocol

A novel bifunctional-group multi-purpose dye probe p-TNS has been designed and synthesized. The probe p-TNS has unique excited-state intramolecular proton transfer (ESIPT) and resonance-assisted hydrogen bonding (RAHB) coupled system, was confirmed to detect cyanide and hydrazine by blocking the ESIPT effect. Cyanide can change the fluorescence of the solution from bright green to orange-red (116 nm Stokes shift), while hydrazine causes the bright green fluorescence to be quenched. The recognition mechanism of the probe p-TNS to CN^- and N₂H₄ was proposed reasonably through spectral characterizations and theoretical calculations. Combined with theoretical calculations, it was speculated that the solvent dependence may be caused by the ICT effect in the molecule. The probe p-TNS could be prepared into test strips for the detection of cyanide and hydrazine. In addition, the probe molecule can also be used to detect trace amounts of cyanide in agricultural products, and respond to gaseous hydrazine by direct contact, indicating that the probe p-TNS has good practical application prospects. Therefore, this molecular framework provides a new way of thinking about detecting multiple target substances.

A Bis(Salamo)-Based Fluorogenic Sensor for Highly Selective and Sequential Recognition of Cu2+ and B4O72- Ions in Semi-Aqueous Medium

A new type of multifunctional bis(salamo)-based fluorogenic sensor H₂BS was designed and synthesized. Under the action of V_DMF: V_H2O = 9: 1, the fluorogenic sensor can identify Cu²⁺ and B₄O₇^2-, in which N and O atoms can serve as binding sites for Cu²⁺ and B₄O₇^2-, the stoichiometry of the binding of the fluorogenic sensor H₂BS and Cu²⁺ has been confirmed by titration experiment, working curve, ESI-MS analysis and DFT calculation. The pH response experiment also confirmed that the fluorogenic sensor can recognize Cu²⁺ and B₄O₇^2- in the pH range applicable to the physiological environment. The minimum detection limit of H₂BS for Cu²⁺ and B₄O₇^2- recognition reaches 1.12 × 10^-7 and 5.56 × 10^-8 M, and the fluorogenic sensor H₂BS has been successfully applied to Cu²⁺ detection in actual water samples, and the test strip for detecting Cu²⁺ and B₄O₇^2- was obtained. Meanwhile, the success of the test strip experiment made the fluorogenic sensor H₂BS to recognize Cu²⁺ and B₄O₇^2- widely used in daily life. A new type of salamo-based multifunctional fluorogenic sensor H₂BS was designed and synthesized to identify Cu²⁺ and B₄O₇^2- in aqueous solvent systems. Added Cu²⁺ to H₂BS can cause fluorescence quenching. Further experiments showed that H₂BS and Cu²⁺ form a stable 1:2 complex, while B₄O₇^2- can also cause fluorescence quenching of H₂BS, which is the occurrence of the PET effect. Meanwhile, H₂BS can be used for quantitative detection in the environment and rapid identification in life.

Insight into Rare Structurally Characterized Homotrinuclear CuII Non-Symmetric Salamo-Based Complex

A rare homotrinuclear CuII salamo-based complex [Cu3(L)2(μ-OAc)2(H2O)2]·2CHCl3·5H2O was prepared through the reaction of a non-symmetric salamo-based ligand H2L and Cu(OAc)2·H2O, and validated by elemental analyses, UV-Visible absorption, fluorescence and infrared spectra, molecular simulation and single-crystal X-ray analysis techniques. It is shown that three CuII atoms and two wholly deprotonated ligand (L)2− moieties form together a trinuclear 3:2 (M:L) complex with two coordination water molecules and two bi-dentate briging μ-acetate groups (μ-OAc−). Besides, the Hirshfeld surface analysis of the CuII complex was investigated. Compared with other ligands, the fluorescent strength of the CuII complex was evidently lowered, showing that the CuII ions possess fluorescent quenching effect.

Two novel tetraphenylethylene-skeleton salamo-type fluorescent probes: specific recognition of cyanide through different response patterns

The possible sensing mechanism of probes TPES1 and TPES2 towards CN− ions.