Structural and computational studies of Schiff base ligand and its metal complexes: Synthesis, solvent effects by post-synthetic modification, computational and selective hazardous sulfide anion detection

Abstract

We have reported the synthesis and crystal structure analysis of the new Schiff base ligand (Z)-2,4-diiodo-6-(((2-(methylthio)phenyl)imino)methyl)phenol (SL6) and its copper complexes (complex-1: [Cu(SL6)(CH3COO)]n complex-2: [Cu(SL6)(CH3COO)(CH3COOH)]). Post-synthetic modification of complex-1 by solvent-induced effects leads to the formation of complex-2. The crystal structure and computational studies were used to investigate the influence of solvents on structural conformation, coordination polyhedral and supramolecular architecture. The copper complex-1 is a coordination polymer that exhibits interesting type-II halogen‧‧‧halogen tetramer synthon. In complex-2, the polymeric chain is replaced by the 1-D hydrogen-bonded chain influenced by the coordinated acetic acid. Hirshfeld surface, 2-D fingerprint plots, enrichment ratio and QTAIM analysis, were utilized to examine the nature of various noncovalent interactions. The DFT studies were conducted to investigate the electronic properties and local and global parameters of ligand and complexes. Furthermore, in-situ prepared Cu(SL6)(CH3COO)2 receptor was employed for selective detection of hazardous sulfide anion in the vicinity of other anions in aqueous acetonitrile HEPES buffer by utilizing UV–Visible spectroscopic and colourimetric study.