Computational Design of Zinc Single-Atom Catalysts in Lantern Organic Framework

The design of the metal-support interface is fundamental to the performance of single-atom catalysts (SACs). Here, we present a comprehensive computational study by using Density Functional Theory (B3LYP-D3/LANL2DZ for zinc atoms and 6-31+G(d) for other nonmetal atoms) in Zinc-embedded Lantern Organic Frameworks (Zn@LOFs) to resolve this design. By systematically comparing sp- and sp³-bridging motifs, we reveal a critical structural dichotomy: while flexible sp³-frameworks favor endo-configuration, rigid sp-bridging systems introduce a unique kinetic trap that stabilizes accessible exo-configuration. Crucially, agglomeration analysis confirms that the sp-LOF architecture could suppress ZnZn clustering. Beyond stability, we demonstrate precise electronic tunability; endo-Zn_n@sp-LOFs leverage metal-ligand π-conjugation to significantly narrow the HOMO-LUMO gap, whereas endo-Zn_n@sp³-LOF affects the gap slightly. Furthermore, electron transport analysis based on Yoshizawa's orbital rules confirms that these constructs maintain good molecular conductance between two ends of the framework-protected Zn-Zn metal chains (10^-2 to 10^-3 G₀; Log[G₀] from -2 to -3), despite smaller values in comparison to the free-standing zinc metal chains. Moreover, the predicted gas adsorption behavior indicates that CO₂ is predicted to interact more strongly than CO, with adsorption strength modulated by the LOF motifs and the presence and position of Zn centers. These findings establish Zn@LOFs not merely as passive supports, but as tunable, dual-function platforms capable of integrating potential single-atom catalysis with efficient charge transport.