A Structurally Distinct High-Entropy Zeolitic Imidazolate Framework Enabled by Entropy-Assisted Co-Ligation

High-entropy metal-organic frameworks are commonly realized within framework families that are already accessible as isostructural single-metal analogues. As a result, multimetal incorporation usually preserves pre-existing topologies rather than generating structurally distinct frameworks. In zeolitic imidazolate frameworks (ZIFs), this challenge is amplified by strong metal-imidazolate preference, rendering structurally distinct high-entropy ZIFs particularly elusive. Here we report an entropy-assisted coligation strategy that enables the synthesis of a genuinely distinct high-entropy zeolitic imidazolate framework (HE-ZIF), [Fe0.26Ni0.23Mn0.26Co0.2Zn0.05(C2O4)(Hmim)2]n from an equimolar five-metal system. In contrast to conventional ZIF chemistry, this HE-ZIF does not inherit the tetrahedral topology of known single-metal ZIFs. Instead, three-dimensional electron diffraction resolves a new monoclinic structure featuring multimetal nodes, reduced metal-imidazolate coordination, and enhanced linker flexibility. Synchrotron powder diffraction further confirms that this distinct framework is retained as the bulk single phase. Residual coordination maps derived from density functional theory calculations show that increasing configurational complexity progressively balances metal-ligand coordination preferences, enabling coligation inaccessible in low-entropy systems. This design extends to additional multimetal compositions. As a proof of concept, incorporation of HE-ZIF into a perfluorosulfonic acid matrix improves proton conductivity by more than 55% relative to Nafion at 70 °C, demonstrating functional utility of the resulting coordination environment.