Design and Dual-Functional Inhibition of Copper-Based Coordination Polymers for Sustainable Regulation of Soil Nitrogen Transformation.

Widespread use of nitrogen fertilizers, especially urea, can contribute to environmental challenges such as nitrate leaching and nitrous oxide emissions, particularly in high-input systems. All of the copper-based coordination polymers (Cu-CPs) exhibited strong inhibitory effects on urease, Cu-CP-1, featuring a trinuclear copper cluster and zigzag chain, showed the narrowest highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gap among the four compounds (ΔE = 0.136 eV), indicating high chemical reactivity and favorable electron-transfer capability, and the highest urease binding affinity (-10.32 kcal mol-1) by density functional theory (DFT) and molecular docking. Cu-CPs demonstrated a dual-level mechanism: directly inhibiting urease at the molecular level and releasing Cu2+ to suppress ammonia-oxidizing microorganisms (AOA/AOB) via amoA downregulation, thereby impeding nitrification. Reduced nitrate accumulation further downregulated denitrification genes (nirK, nirS, nosZ), establishing cascade inhibition from nitrification to denitrification. Cu-CP-1 and Cu-CP-2 exhibited superior sustained dual inhibition, effectively delaying nitrogen transformation and reducing loss. This work offers a promising strategy for sustainable agricultural nitrogen management.