Multi-Template-Guided Synthesis of High-Dimensional Molecular Assemblies for Humidity Gradient-Based Power Generators

Systematically orchestrating fundamental building blocks into intricate high-dimensional molecular assemblies at molecular level is imperative for multifunctionality integration. However, this remains a formidable task in crystal engineering due to the dynamic nature of inorganic building blocks. Herein, we develop a multi-template-guided strategy to control building blocks. The coordination modes of ligands and the spatial hindrance of anionic templates are pivotal in dictating the overall structures. Flexible multi-dentate linkers selectively promote the formation of oligomeric assembly ([TeO₃(Mo₂O₂S₂)₃O₂(OH)(C₅O₂H₇)₃]^4- {TeMo₆}) into tetrahedral cages ([(TeO₃)₄(Mo₂O₂S₂)₁₂(OH)₁₂(C₉H₉O₄P)₆]^8- {Te₄Mo₂₄} and [(AsO₄)₄(Mo₂O₂S₂)₁₂(OH)₁₂(C₉H₉O₆)₄]^12- {As₄Mo₂₄}), while steric hindrance from anionic templates further assists in assembling cages into an open quadruply twisted Möbius nanobelt ([(C₆H₅O₃P)₈(Mo₂O₂S₂)₂₄(OH)₂₄(C₈H₁₀O₄)₁₂]^16- {P₈Mo₄₈}). Among these structures, the hydrophilic-hydrophobic hybrid cage {Te₄Mo₂₄} emerges as an exemplary molecular model for proton conduction and serves as a prototype for humidity gradient-based power generators (HGPGs). The Te₄Mo₂₄-PVDF-based HGPG (PVDF=Poly(vinylidene fluoride)) exhibits notable stability and power generation, yielding an open-circuit voltage of 0.51 V and a current density of 77.8 nA cm^-2 at room temperature and 90 % relative humidity (RH). Further insights into the interactions between water molecules and microscale molecules within the generator are achieved through molecular dynamics simulations. This endeavor unveils a universal strategy for synthesizing multifunctional integration molecules.