Synthesis of new hexakis-heterocyclic compounds and their use in the formation and stabilization of Au and Ag nanoparticles

摘要

The stabilization of nanoparticles in solution is a challenge of major proportions, and avoiding the formation of aggregates and eventual coalescence of particles is directly linked to the conservation of its unique properties. In this work, we reported the synthesis of two hexakis-heterocyclic compounds, containing the tetrazole or 2-amino-l,3,4-thiadiazoIe group, respectively. The hexa-heterocyclic compounds were used in the synthesis and stabilization of Au and Ag nanoparticles. To obtain these molecules was used phosphonitrilic chloride trimer compound as core, which reacted with phenols properly substituted in the para position with either cyano or aldehyde group. The cyano group was successfully converted to the corresponding tetrazole using a 1,3-dipolar cycloaddition reaction with ammonium azide generated in situ. In the case of aldehyde derivative, it was converted to the corresponding thiosemicarbazone, which was further cyclized using FeCl_3. Compounds were characterized by RMN and IR spectroscopy. The UV-Vis spectroscopy was used for nanoparticles analysis.