New Thiophene Monolayer‐Protected Copper Nanoparticles: Synthesis and Chemical‐Physical Characterization

Abstract

For the first time copper 3‐(6‐mercaptohexyl)thiophene‐protected nanoparticles (Cu T6SH) have been synthesized by a one‐phase system, utilizing an NaBH 4 /LiCl mixture in diglyme as the reducing reagent and avoiding water medium dissolving copper salts. The prepared nanoclusters, characterized by transmission electron microscopy (TEM), have shown a constant spherical morphology with a size dimension of 5‐6 nm in diameter. After their synthesis, no morphological evolution and irreversible aggregation process has been observed after a storage in CH 2 Cl 2 at low temperature for a period up to six months long. Cu T6SH nanoparticles have been investigated by UV‐Visible (UV‐Vis) and Fourier transmission infrared (FTIR) spectroscopes to characterize the alkylthiophenes monolayer conformations and the particles optoelectronic properties. The UV‐Vis reveals the lack of the surface plasmonic band, previously observed in Cu‐nanosized clusters at about 556–570 nm, and shows a wide‐band centered at 293 nm, probably due to the high‐conformational surface ordering of thiophene rings on the Cu core. The results highlight the importance of the modifications ported to the well‐known one‐phase synthetic reactions to obtain a clear lack, even after a storage of six months, of any irreversible aggregation that has always characterized chain thiophene‐protected metallic nanoparticles.