Zirconium and tin phosphonates were synthesized to determine ion-exchange preference and radiolytic stability. The Sn and Zr phosphonate materials were found to have preference for highly charged ions (3+) over lower charged ions (1+, 2+). The materials were exposed to 3.18 × 106 Gray from a Co-60 gamma source and were shown to retain their structure and performance. Ion-exchange of radioactive Am-241 with varying pH was also explored. In this paper, we describe these unusual ion-exchangers that are simple to prepare, reproducible, and do not require phosphate addition.