A composition comprising at least one first divalent unit represented by formula: and at least one of a second divalent unit comprising a pendant Z group or a monovalent unit comprising a thioether linkage and a terminal Z group, wherein each Z group is independently selected from the group consisting of —P(O)(OY)2 and —O—P(O)(OY)2. R″ and R″′ are each independently selected from the group consisting of hydrogen and alkyl having from 1 to 4 carbon atoms. Y is selected from the group consisting of hydrogen, alkyl, trialkylsilyl, and a counter cation. Methods of treating a surface using these compositions and articles with a surface in contact with these compositions are provided. Methods of making these compositions are also provided.