From 3-fold to 6-fold: tuning interpenetration of Zn-triphenylenehexathiolate MOF through precursor hydration

Abstract

Controlling the network topology in crystalline materials is a key challenge in crystal engineering. While masked synthesis has facilitated the growth of single-crystal thiol–metal–organic frameworks (S-MOFs), achieving precise control over complex features, such as interpenetration, remains difficult. We show that the metal precursor's hydration level acts as a crucial switch that guides the framework topology. Simply replacing hydrated zinc acetate (Zn(OAc)₂·2H₂O) with anhydrous Zn(OAc)₂ results in a significant topological change from a three-fold (Zn-HTT-3F) to a six-fold interpenetrated framework (Zn-HTT-6F), based on [ZnS₄] nodes and hexathioltriphenylene linkers. Single-crystal analysis uncovers a hierarchical “intertwining of sub-nets” packing mode in Zn-HTT-6F, highlighting precursor engineering as an effective strategy for controlling network topologies.