Polyhedral Metal-Imidazolate Cages: Control of Self-Assembly and Cage to Cage Transformation

A series
of neutral cubic nickel­(II)-imidazolate Ni8L12X4 cages were prepared by rational choices
of substituents and anions with solvothermal subcomponent self-assembly
technology. Both substituents and halide anions play a critical role
in the formation and stabilization of cubic cages. Changing one of
the factors in the reaction will switch the final structure to a Ni14L24 rhombic dodecahedral cage. The cubic cage
can transform to a large rhombic dodecahedral cage in the presence
of methylamine at room temperature accompanied by a color change from
purple to light yellow.