Thionicotinamide SAM on Gold: Adsorption Studies and Electroactivity

Abstract

STM and impedance results of the self-assembled monolayer (SAM) formed with thionicotinamide (TNA) on gold indicate the presence of defects that increase with the immersion time of the electrode in the TNA solution affecting the SAM electroactivity toward the electron transfer reaction of the cytochrome c metalloprotein and [Fe(CN) 6 ] 4À and [Ru(NH 3 ) 6 ] 3þ complexes. It was observed that this electroactivity was also affected by the pH of the electrolyte solution. SERS and STM data indicate sulfur coordination to the surface with contribution of the NH 2 group. From the dependence of the TNA surface coverage on the temperature and concentration in solution, thermodynamic parameters of adsorption were determined.

Substrate Effects in the Self-Assembling of N,N-Diphenylquinodimethyl Thioamide on Transition Metals

“…In recent years, increasing attention has been received on thioamide transition-metal complexes due to their high catalytic activities and the nature of the CS bond. − So far, thioamide transition-metal complex catalysts have been extensively employed in the Mizorroki–Heck reaction, , Suzuki–Miyaura reaction, , amide synthesis, alcohol oxidation, and C–H bond functionalization. − The remarkable catalytic performance of thioamide transition-metal complexes inspires people to investigate the interaction of thioamides with transition metals, especially thioamide self-assembly on transition-metal surfaces that hold promise as a novel catalytic system. − In this regard, various simple thioamide molecules, such as thiadiazole, 2-mercapto pyrimidine, , and thiourea , deposited on metal surfaces, have been studied. Despite their better stability and catalytic reactivity, the on-surface self-assembly of novel exotic thioamide molecules remain largely unexplored. , …”