Novel structurally characterized hetero-bimetallic [Zn(II)2M(II)] (M = Ca and Sr) bis(salamo)-type complexes: DFT calculation, Hirshfeld analyses, antimicrobial and fluorescent properties

Two hetero-bimetallic [Zn(II)(2)M(II)] (M = Ca and Sr) complexes [Zn2Ca(L)(OAc)(2)] (1) and [Zn2Sr(L)(OAc)(2)] (2) with a novel asymmetrical bis(salamo)-type tetraoxime ligand (H5L) were designed and synthesized, and characterized by elemental analyses, FT-IR spectra, UV-vis absorption spectra, Density Functional Theory (DFT) calculation, Hirshfeld surface analyses and X-ray single crystal diffractions. Compared with the symmetric bis(salamo)-type ligands, the ligand H5L and its [Zn(II)(2)M(II)] (M = Ca and Sr) asymmetrical bis(salamo)-type complexes synthesized for the first time in this paper have more novel structures and better properties. The results of ultraviolet titration show that the coordination ratio of ligand, alkaline earth metal and transition metal is 1:1:2. Complexes 1 and 2 have good luminescent properties and obvious antimicrobial activities.