Redefining the Minimal Editable Unit of Supramolecular Synthons: A 1→2 Lattice-Editing Strategy in Ternary...

Conventional multicomponent crystal engineering is largely restricted to one-to-one component substitution, which often provides limited tunability or disrupts the parent lattice structure. Inspired by skeletal editing in molecular chemistry, we herein establish a lattice-editing strategy for supramolecular crystals. This work extends the conventional understanding of the minimal editable structural unit in supramolecular crystals from individual components to local supramolecular structural units, thereby moving beyond strict numerical equivalence and enabling non-stoichiometric component substitution while preserving the original interaction topology. As a proof of concept, a 1→2 component substitution was achieved in the ternary ionic crystal ethylenediamine diperchlorate hemihydrate (EP·0.5H₂O) by replacing the [H₂eda]²⁺-H₂O composite unit with [H₂pda]²⁺. The resulting anhydrous energetic crystal PEP fully retains the parent crystal framework, space group, cell parameters, and hydrogen-bonding network. PEP exhibits a high density of 1.85 g cm^{- 3}, a phase-transition temperature increased by approximately 90°C, and a 127% enhancement in formation enthalpy. In solid propellant formulations, PEP delivers higher specific impulses than AP and ADN while simultaneously improving thermal stability, environmental stability, and mechanical safety. This work demonstrates precise lattice editing in multicomponent crystals and provides a general strategy for the rational design of high-performance functional crystalline materials.