Exploring the structural characteristics of novel Zn(II) complex and Ni(II) coordination polymer with a salamo-like ligand containing an exposed aldehyde

Abstract

In the first step, we synthesized a nonsymmetric salamo-like ligand, H2L, featuring 4-hydroxyisophthalaldehyde and 6‑methoxy-2-[O-(1-ethoxyamide)]oxime phenol. In the subsequent phase, Zn(II) and Ni(II) complexes, namely [Zn2(L)2]·2CH3CN·CH3OH and [Ni(L)(H2O)]n·nCH3COCH3, were obtained by treating H2L with Zn(II) and Ni(II) ions via a solvent volatilization method. Structural characterizations were carried out using various techniques, including 1H NMR, MS, and X-ray diffraction analysis. Where the phenolic oxygen atoms (O4, O8) bridging two metal atoms (Zn1, Zn2), both five-coordinated Zn(II) atoms are in twisted triangular bipyramidal geometrical configurations, while the Ni(II) atom exhibits a six-coordinated octahedral geometric configuration, the formyl group only participates in the coordination of Ni(II) atom. The existence of multiple interactions, as well as charge distributions between the complexes or CPs (coordination polymers), has also been demonstrated through theoretical calculations IRI (Interaction region indicator), MESP (Molecular electrostatic potential) and Hirshfeld, etc. Fluorescence experiment revealed a significant enhancement in fluorescence intensity upon addition of Zn(OAc)2·2H2O, while the fluorescence intensity was quenched upon addition of Ni(NO3)2·6H2O.