A flexible, 2-fold interpenetrated 3D supramolecular structure [Cu(ndc${}^{2-}$)(1,10-phen)]${}_{\mathrm{n}}$ (where ndc${}^{2-}=2$,6-napthalenedicarboxylate and 1,10-phen = 1,10-phenanthroline) comprising neutral 2D metal–organic layers as the basic building block was prepared. Structural study reveals that metal ions are bridged by ndc${}^{2-}$ ligands to form 2D coordination layers and the coordinated 1,10-phen moieties are hanging from the layers in the interlamellar spaces. The gliding motion of $\pi \cdots \pi$ stacked layers through 1,10-phen moieties was found to be responsible for the flexibility of MOF and the consequent extended conjugation also rendered semiconducting behaviour in the material. Thermal stability studies revealed that the framework was pretty stable below 260°C. Additionally, the MOF was characterized by performing BET adsorption and photoluminescence studies. Further, the MOF was calcinated at 650°C to prepare well defined, nearly uniform and spherical shaped CuO nanoparticles (CuO-NPs) with an average size of $\sim$25 nm. Interestingly, CuO-NPs showed around 16 times more conductivity (4.8 × 10⁻² S/cm) in relative to the parent MOF (3 x 10⁻³ S/cm). CuO-NPs induced cross-coupling reactions of alcohols and thiols with arylhalides have been reported. A simple, general, ligand-free and solvent-free procedure for the efficient synthesis of the cross-coupled products in high yield was successfully demonstrated.