Remarkable effect of the dithiafulvene structures on their capacity as reducing agents: Influence of conjugated thiocarbonyl group

Abstract

The use of dithiafulvene (DTF) derivative compounds having strong electron donating properties as reducing agents to obtain noble metal nanoparticles (PdNP, AgNP, AuNP) is demonstrated. The resulting oxidized DTF product was characterized by spectroelectrochemistry. The stability of the colloidal dispersions are explained considering that the oxidized DTF layer have a delocalized positive charge providing both steric and electrostatic stabilization, which allows that the generated nanoparticles remain in a colloidal state for six months or more. Our results suggest that the presence of a thiocarbonyl group in DTF moeity increases the stability of the oxidized DTF (radical cation DTF 2 +[rad] ), avoiding the formation of the tetrathiafulvene (TTF) as occurs with other derivatives reported in literature, which do not have a conjugated thiocarbonyl group in their structure. It has also been shown that the capacity as a reductive agent of DTF strongly depends on the substitution pattern of the base structure.