Diamondoid Frameworks via Supramolecular Coordination: Structural Characterization, Metallogel Formation, and Adsorption Study

Supramolecular coordination has been developed as an efficient tool to construct a variety of discrete metallacycles and metallacages with well-defined shapes and sizes. However, its application in framework construction has been barely exploited. In this paper, we report the direct synthesis of two diamondoid frameworks from a simple tetrahedral precursor, tetra(4-(4-pyridinyl)phenyl)methane, and two linear difunctional platinum(II) ligands via one-step supramolecular coordination. Controlled by the specific angularity and geometry of the tetrahedral and linear subunits, these frameworks possess a well-defined diamondoid topology with highly regulated periodicity and three-dimensional porosity. Moreover, these rigid frameworks can be directly changed into a metallogel when prepared in DMSO at high concentrations. Interestingly, these diamondoid frameworks exhibit a cationic nature and stimuli-responsive behavior, which potentially endow them with the selective adsorption and controlled release for anionic dyes and drugs in aqueous environments. Thus, this study demonstrates that supramolecular coordination is a facile and efficient approach for the preparation of functional framework materials containing predesigned and well-defined supramolecular coordination assemblies as molecular skeletons.