JOURNAL OF MOLECULAR STRUCTURE, vol.1269, 2022 (SCI-Expanded)
In this work, syntheses of Schiff-base ligand, N-2-(6-methylpyridyl)-2-hydroxy-1-naphthaldimine ( 1 ) and its hitherto unknown chelate with a Ni(II) salt, bis[N-2-(6-methylpyridyl)-2-oxo-1-naphthaldimnato-k3N <^> N <^> O] nickel(II) ( 2 ) have been reported and characterized by spectral techniques (IR, 1 H NMR, Mass). Solid state structures and non-covalent interactions persisting in 1 and 2 are studied by Density Functional The-ory (DFT) optimizations and Hirshfeld Surface (HS) analysis. X-ray diffraction (XRD) study shows zwitter ionic keto-amine tautomer form of planar Schiff base 1 that exists as dimer formed by C13 -H13A middotmiddotmiddotO1i [(i)-x + 1,-y,-z + 1] hydrogen bonds and distorted octahedral geometry around Ni + 2 center in chelate 2, where overall crystal structure stability may be attributed to weak C -H middotmiddotmiddot pi, pi middotmiddotmiddot pi stacking, van der Waals interactions, and C - H middotmiddotmiddotO type intermolecular hydrogen bonds. The HS study and 2D Finger Print (FP) plots corroborate well with XRD data and show prominent O middotmiddotmiddotH/H middotmiddotmiddotO spikes (2.2 A < de +di < 2.3 A) and C middotmiddotmiddotH/H middotmiddotmiddotC (2.5 A < de +di < 2.6 A) spikes that arise from C-H middotmiddotmiddotO type H-bonds and C - H middotmiddotmiddot pi interactions respectively, along with significant C middotmiddotmiddotC interactions (de +di & SIM;3.3 A) due to pi middotmiddotmiddot pi stacking ( 2) . The anticancer activity has been investigated by using cytotoxicity measure (MTT assay), apoptosis assay, quantitative polymerase chain reaction (qPCR), and colony formation assays. The Ni(II) metal com-plex demonstrates dose-dependent cytotoxicity in vitro , killing A549 lung cancer cells via an apoptotic pathway.(c) 2022 Elsevier B.V. All rights reserved.