Comparative study of the X-ray crystallography temperature, synthesis method, optical properties, NCI-RDG, and Hirshfeld surface analyses of coordination polymer of [CuI(DAFO)(SCN)]n: An amenable precursor for CuO nanoparticles

1D coordination polymer (CP) of [CuI(μ1,3-NCS)(DAFO)]n (CP1) (DAFO =  4,5-Diazafluoren-9-one) has been synthesized through branched tube method in ethanol and compared with previously synthesized CP2. Although both CPs synthesis methods and parameters were different, both of them formed in a similar crystal system (orthorhombic) and space group (Pmn21). The optical properties and structure of CP1 were further investigated in detail by bandgap energy (Eg = 5.63 eV), UV-Vis and FT-IR spectra. The difference in the crystallography temperature (CP1 in 290 K and CP2 in 200 K) causes slight differences in the bond lengths and angles in the geometry center. 3D Hirshfeld surface and 2D fingerprint plots analyses offer the predominance contribution of H–C⋯H (18.9%) for CP1 and H–C⋯H (19.9%) for CP2. The most obvious distinguishes in the interactions in both CPs are C–N (8.4%) and (3.3%), Cu–S (4.8%) and (0.0%), Cu–N (3.3%), and (11.4%) for CP1 and CP2, respectively. Due to the determined asymmetric unit of the crystal structure of both CPs, there are some distinctions in the HS and 2DFP analysis of the CPs. Solvent-free decomposition of CP1 crystals at 750 ℃ led to the synthesis of CuO nanoparticles with particles size of ~12 nm.