The preparation, characterization, and properties of a novel quantum-confined CdS nanocluster containing a chemically active phenolic surface is described, along with a general method for the covalent attachment of a variety of molecular moieties to the cluster via esterification of the surface hydroxyl groups. The introduction of surface reactivity is crucial for the eventual realization of molecular electronic devices fabricated from such nanoclusters or quantum dots. The esterification method described in this contribution occurs under very mild conditions that have been demonstrated not to disturb the integrity of the cluster and can be extended to include such interesting moieties as chromophores, luminophores, or quantum wires. Interestingly, tethering aliphatic chains of moderate length to a CdS nanocluster renders the cluster soluble in a wide variety of common laboratory solvents. Thus, surface phenolic semiconductor nanoclusters can serve as a convenient synthetic starting point for a wide variety of interesting and potentially applicable composite materials.