Metal directed assembly of terpyridine-functionalized gold nanoparticles

Terpyridine capped gold nanoparticles (ca. 2.0 nm diameter) form large aggregates in the presence of metal ions [Fe(II), Zn(II), Cu(I), Ag(I)]. The assembly process is a result of metal coordination between two terpyridines that are attached to separate nanoparticles. The stability of the aggregates in various solvents and in the presence of excess terpyridine can be controlled through choice of bridging metal. Small angle X-ray scattering experiments indicate regular interparticle distances that increase as the length of the supporting monolayer is extended.