Ferrocenylated 1,3,5-triphenylbenzenes for the electrochemical detection of various cations or anions

Three diverse 1,3,5-triphenylbenzene derivatives bearing three ferrocene units (Fc1-Fc3) were used for the construction of electrochemical sensors for the detection of various cations or anions. The obtained derivatives contained imine (Fc1 and Fc2) or amide bonds (Fc3) between 1,3,5-triphenylbenzene and ferrocene skeletons, which further influenced the ability of the as-synthesized ferrocenylated molecules to recognize cations (Cu(ii), Pb(ii), Cr(iii) and Fe(iii); compounds Fc1 and Fc2) or monovalent anions (Br-, I-, ClO4-, NO3-, CH3COO-, and H2PO4-; compound Fc3). In the case of cation recognition, differential pulse voltammetry (DPV) experiments revealed that the Fc1 receptor was characterized by much better sensitivity compared to the Fc2 receptor and the limit of detection (LOD) values ranged from 0.5 to 1.8 μM. Similarly, such very low LOD values (0.7-1.5 μM) were also found in the case of anion recognition by the Fc3 receptor. Importantly, the advantage of the tested Fc receptors is also their long-term stability (sensors were stable at least for 2 months).

Synthesis and structural, electrochemical and photophysical studies of triferrocenyl-substituted 1,3,5-triphenylbenzene: a cyan-light emitting molecule showing aggregation-induced enhanced emission

Triferrocenyl-substituted 1,3,5-triphenylbenzene was successfully synthesized in high yield. Single-crystal X-ray diffraction experiments revealed that the internal rotations of the ferrocenyl moieties are significantly restricted in the solid phase and that there are no significant π stacking interactions therein. The photoluminescence of the crystals is essentially the same as that of dilute chloroform solutions. However, studies of this cyan-light emitting substance in mixtures of chloroform and methanol revealed the aggregation-induced enhanced emission (AIEE) feature that boosts its fluorescence quantum yield from 13% up to 74%. We demonstrate the AIEE effect for a new class of easy-to-prepare aromatic molecules containing several metallocene units for the first time.

Tris(ferrocenylmethidene)sumanene: synthesis, photophysical properties and applications for efficient caesium cation recognition in water

The synthesis of a sumanene derivative bearing three ferrocenyl substituents is presented. This conjugated compound is solution-processable, shows red-light emission with high fluorescence quantum yield and can be used for the construction of the first buckybowl-based sensor for the selective and effective recognition of caesium cations (Cs⁺) in aqueous solution.

AIE based GSH activatable photosensitizer for imaging-guided photodynamic therapy

A novel ferrocene decorated vinyl pyridinium-substituted tetraphenylethylene (TPEPY-S-Fc) linked by a disulfide bond was designed as a GSH activatable photosensitizer by aggregation-induced emission for imaging-guided photodynamic therapy of cancer cells.

New ferrocene-triazole derivatives for multisignaling detection of Cu2+ in aqueous medium and their antibacterial activity

Ferrocene-based naphthalene or quinoline receptors 1-4 linked by triazole were designed and synthesized. Their recognition properties of metal cations have been investigated systematically in aqueous environment. Upon addition 1 equiv. of Cu²⁺ ion, receptors 1 (C₂₃H₁₉FeN₃O) and 2 (C₂₂H₁₈FeN₄O) showed fluorescent turn-off, enhanced absorption and color variations. At the same time, receptor 1 also caused the perturbation of redox potential after addition 1 equiv. of Cu²⁺ ion. Therefore, receptors 1 and 2 behaved as naked-eye chemosensors and fluorescent probes for Cu²⁺ without interference by other ions and with low detection limit. In addition, receptor 1 could also be considered electrochemical sensor for Cu²⁺ having excellent sensitivity and selectivity. However, increasing the molecules flexibility resulted in the lower selectivity of ion recognition in the case of receptors 3 (C₂₄H₂₁FeN₃O) and 4 (C₂₃H₂₀FeN₄O). Furthermore, this series of compounds were nontoxicity and receptor 1 exhibited certain antibacterial activity.

Fluorescent triazolium for sensing fluoride anions in semi-aqueous solution

A new triazolium-based receptor for fluorescent sensing of inorganic fluoride anions in semi-aqueous solution and the solid state was reported.