Oligomeric reagents are provided comprising a moiety of atoms arranged in a specific order, wherein the moiety is positioned between a water-soluble, non-peptidic oligomer and a pharmaceutically active agent. The oligomeric reagents are useful for, among other things, forming oligomer active agent conjugates. Related methods, compositions, preparations, and so forth are also provided.
1. A composition comprising a diamino backbone and an oligomeric reagent, wherein the diamino backbone has the structure
and the oligomeric reagent has the structure-
wherein m-PEG is a methoxy-terminated polyethylene glycol.
2. The composition of claim 1 , wherein the polyethylene glycol has from about 1 to about 30 ethylene glycol monomers.
3. The composition of claim 2 , wherein the polyethylene glycol has from about 1 to about 10 ethylene glycol monomers.