Dynamic Interchain Motion in 1D Tetrathiafulvalene-Based Coordination Polymers for Highly Sensitive Molecular...

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Electrically conductive 1D coordination polymers (CPs) offer theoretical potential for nanoelectronic molecular recognition but face synthesis and property optimization challenges.
• Tetrathiafulvalene-based materials are explored for their unique electronic and structural properties.

Purpose of the Study:

• To synthesize and characterize novel tetrathiafulvalene-based 1D CPs for enhanced electrical conductivity and gas sensing applications.
• To investigate the structure-property relationships governing the performance of these CPs in detecting volatile organic compounds.

Main Methods:

• Synthesis of two new 1D CPs: [Co(m-H2TTFTB)(DMF)2(H2O)]n (Co-m-TTFTB) and {[Ni(m-H2TTFTB)(CH3CH2OH)1.5(H2O)1.5]·(H2O)0.5}n (Ni-m-TTFTB).
• Powder X-ray diffraction (PXRD) to analyze structural flexibility and dynamics.
• Electrical conductivity measurements and gas sensing experiments for volatile organic compounds (VOCs).
• In situ diffuse reflectance infrared Fourier transform spectroscopy and density functional theory (DFT) calculations to elucidate sensing mechanisms.

Main Results:

• Successfully constructed Co-m-TTFTB and Ni-m-TTFTB with improved electrical conductivities due to shorter S···S contacts.
• Demonstrated excellent gas sensing performance for volatile organic compounds, attributed to flexible structures and 1D morphology.
• Achieved a limit of detection for ethanol vapor as low as 0.5 ppm with Co-m-TTFTB, surpassing current state-of-the-art chemiresistive sensors at room temperature.

Conclusions:

• The developed 1D CPs exhibit superior electrical properties and sensitive room-temperature gas detection capabilities.
• The study reveals the molecular insertion mechanism and structure-function relationship for these nanoelectronic sensors.
• This work expands the applications of 1D CPs and establishes a new platform for highly sensitive nanoelectronic gas sensors.