Synthesis, crystal structure, spectral characterization, theoretical and computational studies of Ni(II), Cu(II) and Zn(II) complexes incorporating Schiff base ligand derived from 4-(diethylamino)salicylaldehyde

Three new nickel(II), copper(II), and zinc(II) complexes were prepared by treating symmetrical tetradentate Schiff base ligand (H2L) with Ni(OAc)(2)center dot 4H(2)O, Cu(OAc)(2)center dot H2O, and Zn(OAc)(2)center dot 2H(2)O salts, respectively. The synthesized compounds were structurally characterized by elemental (CHN) and spectroscopic analysis like FT-IR and H-1 NMR. Moreover, the crystal structure of the Ni(II) complex (NiL) has been determined by SC-XRD. The crystal structure investigation confirms that the metal ion is tetra coordinated by ONNO donor sites of ligand to acquire a square planar geometry, which is further compared with some related crystal structures by Cambridge structure database search. A Hirshfeld surface inspection was conducted for the sake of further investigation of the non-covalent interactions in NiL. An enrichment ratio is also calculated for the chemical species to determine the tendency of their interactions in the crystal packing. The theoretical values based on DFT using B3LYP/Def2-TZVP level of theory ensured that the expected consequences matched the experimental findings.

Automated summary

In this study, three new nickel(II), copper(II), and zinc(II) complexes were synthesized and structurally characterized, with the crystal structure of the nickel(II) complex confirmed. Non-covalent interactions in the complexes were investigated and the enrichment ratio of chemical species was calculated.