A multiresponsive two-arm ferrocene-based chemosensor molecule for selective detection of mercury

Area of Science:

• Organometallic chemistry
• Supramolecular chemistry
• Chemical sensing

Background:

• Development of novel chemosensors for heavy metal detection is crucial.
• Indole and ferrocene moieties offer unique electronic and redox properties.
• Unsaturated nitrogen linkers provide a versatile platform for molecular design.

Purpose of the Study:

• To synthesize and characterize a novel indole-ferrocene-indole triad.
• To investigate its electrochemical, electronic, and cation sensing properties.
• To evaluate its potential as a selective chemosensor for metal cations, particularly Hg(2+).

Main Methods:

• Synthesis of the indole-ferrocene-indole triad.
• Electrochemical analysis (cyclic voltammetry) to determine redox properties.
• UV-Vis spectroscopy to study electronic transitions and colorimetric changes.
• Nuclear Magnetic Resonance (1H NMR) and Density Functional Theory (DFT) calculations for structural and bonding insights.

Main Results:

• The synthesized triad exhibits dual-redox behavior and acts as a chromogenic chemosensor.
• Selective and sensitive detection of Hg(2+) cations was achieved, indicated by an anodic shift in redox potential (ΔE(1/2) = 210 mV) and a red-shift in absorption spectrum (Δλ = 120 nm).
• Complexation with Hg(2+) resulted in a distinct color change from orange to green, facilitating naked-eye detection.

Conclusions:

• The indole-ferrocene-indole triad functions as a highly selective and effective dual-redox and chromogenic chemosensor for Hg(2+).
• The observed color change allows for straightforward visual identification of mercury ions.
• The study demonstrates the potential of this molecular design for developing advanced sensing materials.