Four new Zn(II) complexes based on 2-thienoyltrifluoroacetone and N-donor auxiliary bridging and chelating ligands: Synthesis, spectroscopic and structural studies, thermal behavior and Hirshfeld surface analysis

Abstract

Two new mononuclear complexes,[Zn(2,2′-bpy)(ttfa)2] (1), [Zn(1,10-phen)(ttfa)2] (2) and two one dimensional coordination polymers, [Zn(bpp)(ttfa)2]n (3) and [Zn(bpe)(ttfa)2]n (4) (Httfa = 2-thenoyltrifluoroacetone, 2,2ʹ-bpy = 2,2ʹ-bipyridine, 1,10-phen = 1,10-phenanthroline, bpp = 1,3-bis(4-pyridyl)propane and bpe = 1,3-bis(4-pyridyl)ethane), have been synthesized. They were fully characterized by single-crystal X-ray diffraction, elemental analyses, FT-IR and 1H NMR spectroscopy and thermogravimetry. The zinc atoms show distorted octahedral coordination geometries. In addition to evaluate the thermal behavior of the compounds, the 3D Hirshfeld surface analysis and 2D fingerprint maps were used for quantitative mapping of the intermolecular interactions. The emission characteristics of Zinc(II) complexes are influenced by the ligands present, which in turn affect the environment of the Zinc(II) ion. This tuning leads to changes in photoluminescence (PL), absorption (Abs) spectra and quantum yield.