New compounds are provided that may be used to chelute a metal. The compound comprise polyazamacrocyclic compound with at least one phosphonic group substituted on at least one of the aza groups of the polyazamacrocyclic compound. Methods for preparing the compounds are also provided. Methods for preparing a diagnostic imaging agent using the compounds and methods for diagnostic imaging are further provided. Methods for preparing a therapeutic agent using the compounds and methods for therapy are further provided.