Gateway Reactions to Diverse, Polyfunctional Monolayer-Protected Gold Clusters

Amide and ester coupling reactions of omega-functionalized monolayer-protected gold cluster molecules (MPCs) are an exceptionally efficient avenue to a diverse variety of polyfunctionalized MPCs starting from a small subset of omega-functionalized materials. In this paper, coupling reactions have been employed to produce 13 MPCs bearing multiple copies of a diverse variety of structural groups. Detailed features of three of the 13 polyfunctionalized products are highlighted: (a) stepwise coupling and deprotection reactions result in an MPC surrounded by ca. eight pendant tripeptides, (b) a preliminary Steady-State Electron Paramagnetic Resonance (SSEPR) experiment is described for MPCs bearing multiple spin labels (ca. 13/cluster), and (c) a polyelectron electrochemical reaction is described for an MPC bearing multiple (ca. 7/cluster) coupled phenothiazine derivatives. The coupling reactions substantially expand the available diversity of MPCs as polyfunctionalized chemical reagents platformed on a nanometer-sized central core.