Synthesis, supramolecular insight, Hirshfeld surface analyses and optical properties of Fe(II) and Cu(II) complexes of flexible imidazole tethered 1,8-naphthalimide

Two mononuclear complexes of transition metal {Fe(II) and Cu(II)} constructed from 2-(3-(1H-imidazol-1-yl)propyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (L)and KSCN as auxiliary ligand are reported. Both the complexes were formed in refluxed condition. The complexes were characterized with different spectroscopic tools such as FT-IR, UV–vis, CHN-elemental analysis, photoluminescence. The solid-state structures were determined by single crystal X-ray diffraction method which exhibit that Fe (II) center, in complex 1, is four coordinated distorted tetrahedral geometry whereas Cu(II) center, in complex 2 is five coordinated square pyramidal geometry with slight distortion. The bulk stability was confirmed by powder XRD data. The thermal stability of both complexes was determined by thermogravimetric analysis (TGA). Various types of supramolecular interactions such as O–H…O, C–H…O, π…π, C–H…π and C–H…S were observed in the x-ray structures, and all these interactions guide the formation of 3D supramolecular architecture in the solid-state of both complexes. Besides these, the 2D-fingerprint (2D-FP) and Hirshfeld surface analysis (HSA) computations were served to prove the 2D-network packed crystal lattice interactions.