A General Strategy for Hollow Metal‐Phytate Coordination Complex Micropolyhedra Enabled by Cation Exchange

The ability to incorporate functional metal ions (M n+ ) into metal-organic coordination complexes adds remarkable flexibility in the synthesis of multifunctional organic-inorganic hybrid materials with tailorable electronic, optical, and magnetic properties. Herein, we report the cation-exchanged synthesis of a diversity of hollow M n+ - phytate (PA) micropolyhedra via the use of hollow Co 2+ -PA polyhedral networks as templates at room temperature. The attributes of the incoming M n+ , namely Lewis acidity and ionic radius, determine not only the feasibility of achieving complete exchange of the parent Co 2+ ions but also the degree of morphological deformation of the resulting hollow micropolyhedra. New functions can be obtained for both completely and partially exchanged products, as supported by the observation of Ln 3+ (Ln 3+ = Tb 3+ , Eu 3+ , and Sm 3+ ) luminescence from the as-prepared hollow Ln 3+ -PA micropolyhedra after surface modification with dipicolinic acid as an antenna and by the achievement of new potential application of the resulting Fe 3+ - and Mn 2+ -PA polyhedral complexes as magnetic contrast agents. These advances allow one to use cation exchange to facilely synthesize multifunctional hollow M n+ -PA micropolyhedra with an additional control of their physicochemical attributes, enabling exciting opportunities for them in biological and medical applications.