Practical and computational studies on novel Schiff base complexes derived from green synthesis approach: Conductometry as well as in-vitro screening supported by in-silico study

A new Schiff base ligand was prepared and characterized then used to synthesize new metal ion complexes using ball milling technique. These complexes were elucidated by analytical, spectral and conformational tools, to establish their formulae. Mononuclear complexes (1M:1L) were proposed through neutral or mononegative mode within bidentate or tridentate binding. Octahedral configuration was proposed for all complexes except Pd(II) complex has square-planer geometry. EDX, SEM and XRD were used to known the elemental percentage, topographic features as well as the magnitude of crystallinity. Kinetic and thermodynamic parameters were estimated by two known methods. Conductometric titration were carried out for Cu(II) and Ni(II) ions in presence or absence of the ligand to obtain association and formation constants. Crystal explorer software was used to build 3-D models for crystal packing systems according to Hirshfeld method. Strong molecular contact was observed for ligand models with high contribution for oxygen atom. Biological screening was elaborately handled towards microorganism, free radicals and colorectal carcinoma cell line (HCT-116). Excellent inhibition activity was clearly appeared with the ligand which sometimes exceeded reference drugs. Applying MOE, dynamic simulation was executed for the ligand towards different pathogen-proteins at top scoring poses. The interaction affinity towards protein-pockets as well as the electrostatic contour maps represent all interaction possibilities and confirm in-vitro results. (C) 2020 Elsevier B.V. All rights reserved.