Gold and Nickel Extended Thiophenic-TTF Bisdithiolene Complexes

Area of Science:

• Inorganic Chemistry
• Materials Science
• Solid-State Physics

Background:

• Bisdithiolene complexes are known for their potential in molecular electronics.
• Thiophenic-tetrathiafulvalene (TTF) derivatives offer tunable electronic properties.
• Understanding substituent effects on metal-bisdithiolene complex properties is crucial for material design.

Purpose of the Study:

• To synthesize and characterize gold and nickel bisdithiolene complexes with methyl (α-mtdt) and tert-butyl (α-tbtdt) substituted ligands.
• To investigate the impact of bulky tert-butyl substituents on complex formation.
• To evaluate the electrical transport and magnetic properties of the synthesized neutral complexes.

Main Methods:

• Synthesis of gold and nickel complexes under anaerobic conditions.
• Characterization using spectroscopic and analytical techniques.
• Measurement of electrical conductivity and thermoelectric power.
• Magnetic susceptibility measurements.

Main Results:

• Formation of diamagnetic gold monoanion and nickel dianionic species with α-mtdt ligands.
• Synthesis of a unique dinuclear gold(I) complex with α-tbtdt ligands due to steric hindrance.
• Neutral methyl-substituted gold and nickel complexes ([Au(α-mtdt)₂] and [Ni(α-mtdt)₂]) were obtained.
• [Au(α-mtdt)₂] and [Ni(α-mtdt)₂] exhibit metallic properties with significant electrical conductivity and thermoelectric power.
• [Au(α-mtdt)₂] shows Pauli-like magnetic susceptibility, while [Ni(α-mtdt)₂] displays large magnetic susceptibilities indicating high spin states.

Conclusions:

• The steric bulk of the tert-butyl group influences the coordination chemistry of gold bisdithiolene complexes.
• The methyl-substituted gold and nickel bisdithiolene complexes are single-component molecular conductors.
• These findings highlight the potential of tailored bisdithiolene complexes for molecular electronic applications.