This study reports the efficient self-assembly of catena-MOFs (c-MOFs) through the combination of flexible and conjugated naphthalene diimide-based bis-pyridyl ligand (BPND), [M(CN)₂]⁻ (M = Ag or Au), and Fe²⁺ in a one-step strategy. The resulting bimetallic Hofmann-type SCO-MOFs, [Fe⁶(BPND)[Ag(CN)₂]₂]·3CHCl₃ (1Ag) and [Fe⁶(BPND)[Au(CN)₂]₂]·2CHCl₃·2H₂O (1Au), exhibit a unique three-dimensional (3D) structure constructed from polycatenated two-dimensional (2D) layers with hxl topology. Both complexes undergo thermal- and light-induced spin crossover (SCO), leading to simultaneous changes in maximum emission intensity and dielectric constant. This research opens up the possibility of SCO-actuated bistable MIMs with dual functionality of coupled fluorescence emission and dielectricity, making them promising for advanced sensing materials.This study reports the efficient self-assembly of catena-MOFs (c-MOFs) through the combination of flexible and conjugated naphthalene diimide-based bis-pyridyl ligand (BPND), [M(CN)₂]⁻ (M = Ag or Au), and Fe²⁺ in a one-step strategy. The resulting bimetallic Hofmann-type SCO-MOFs, [Fe⁶(BPND)[Ag(CN)₂]₂]·3CHCl₃ (1Ag) and [Fe⁶(BPND)[Au(CN)₂]₂]·2CHCl₃·2H₂O (1Au), exhibit a unique three-dimensional (3D) structure constructed from polycatenated two-dimensional (2D) layers with hxl topology. Both complexes undergo thermal- and light-induced spin crossover (SCO), leading to simultaneous changes in maximum emission intensity and dielectric constant. This research opens up the possibility of SCO-actuated bistable MIMs with dual functionality of coupled fluorescence emission and dielectricity, making them promising for advanced sensing materials.