PEGs have been shown to provide improved water solubility and biocompatibility in drugs and other applications, and the ability to attach a variety of reactive functional groups to the terminal positions of these polymers has greatly increased their utility. Poly(ethylene glycol) (PEG) is a synthetic, hydrophilic, biocompatible polymer with widespread use in biomedical and other applications. PEGs are synthesized using a ring-opening polymerization of ethylene oxide to produce a broad range of molecular weights and molecular weight distributions (polydispersity); however, discrete PEGs (dPEG