Heterogeneity of functional groups in a metal–organic framework displays magic number ratios

Significance Arranging multiple component types in a controlled manner within solid frameworks may one day allow us to combine the heterogeneity characteristic of biological materials with the robustness characteristic of synthetic ones. Here, we report the synthesis of a metal–organic framework whose two component types are incorporated within it in a manner that is robust with respect to changes of solution composition. Calculations done on a model system suggest that this robustness occurs because component types become kinetically trapped during framework growth. Our calculations also show how different controlled arrangements of component types might be obtained by varying their noncovalent interactions, or by varying the topology of the covalent framework within which they are housed.