A half‐sandwich Ta V V dichlorido complex containing an O O , N N , O O ′‐tridentate Schiff base ligand: synthesis, crystal structure and in vitro in vitro cytotoxicity

摘要

A new electroneutral half‐sandwich tantalum(V) dichlorido complex containing pentamethylcyclopentadienyl (Cp*) and the double‐deprotonated version of the Schiff base 2‐ethoxy‐6‐{( E )‐[(2‐hydroxyphenyl)imino]methyl}phenol (H 2 L ) as ligands, namely cis ‐dichlorido(2‐ethoxy‐6‐{( E )‐[(2‐oxidophenyl)imino]methyl}phenolato‐κ 3 O , N , O ′)(η 5 ‐pentamethylcyclopentadienyl)tantalum(V), [Ta(C 10 H 15 )(C 15 H 13 NO 3 )Cl 2 ] or [Ta(η 5 ‐Cp*)( L )Cl 2 ], has been prepared and thoroughly characterized by elemental analysis, IR and NMR spectroscopy, mass spectrometry, density functional theory (DFT) calculations and single‐crystal X‐ray diffraction. The molecular structure revealed that the Ta V centre is coordinated by a η 5 ‐Cp* ligand, two monodentate chlorido ligands and one O , N , O ′‐tridentate L 2? ligand. The crystal structure is stabilized by C—H…C, C—H…Cl and C…C intermolecular interactions. Moreover, the complex shows notable in vitro cytotoxicity against the A2780 human ovarian carcinoma cell line, with IC 50 = 14.4?μ M , which is higher than that of the conventional platinum‐based anticancer drug cisplatin (IC 50 = 20.1?μ M ).