Functionalized polymer with linking group

A functionalized polymer includes an elastomer, a terminal functional group including at least one heteroatom, and a unit intermediate the elastomer and the functional group; the intermediate unit includes a terminal moiety which, in its anionic form, is less basic than a secondary amino radical ion. Methods of making the functionalized polymer and of using it with particulate filler to make, e.g., a tire tread composition also are disclosed.