NOVEL PALLADIUM(II) COMPLEXES OF PYRAZOLE-CONTAINING SCHIFF BASE LIGANDS: SYNTHESIS, STRUCTURAL CHARACTERIZATION, AND CYTOTOXICITY OF THE PALLADIUM(II) COMPLEXES OF 2-{1-[2-(1,3-DIMETHYL-4-NITRO-1H-PYRAZOL-5-YL) HYDRAZONO]ETHYL} PYRIDINE (APHP) AND ITS ANALOGUE 2-{1-[2-(1,3-DIMETHYL-4-NITRO- 1H-PYRAZOL-5-YL)HYDRAZONO]METHYL} PYRIDINE (PCHP)

• Published in: Journal of structural chemistry Vol. 62; no. 7; pp. 1112 - 1122
• Main Authors: Abushamleh, A. S., Abu-Safieh, K. A., Khanfar, M. A., Taher, D., Tahtamouni, L., Alwahsh, N. J.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.07.2021; Springer Nature B.V
• Subjects: Atomic; Atomic/Molecular Structure and Spectra; Chemical analysis; Chemistry; Chemistry and Materials Science; Coordination compounds; Crystal structure; Cytotoxicity; Hydrazones; Imines; Infrared analysis; Infrared spectroscopy; Inorganic Chemistry; Ligands; Molecular; Molecular structure; Nitrogen; NMR; Nuclear magnetic resonance; Optical and Plasma Physics; Organometallic compounds; Palladium; Physical Chemistry; Pyrazole; Single crystals; Solid State Physics; Structural analysis; Toxicity; Schiff base; palladium; biological activities; hydrazone; solid state structure; pyrazol
• ISSN: 0022-4766; 1573-8779
• DOI: 10.1134/S0022476621070167

Treatment of [Pd(PhCN) 2 Cl 2 ] with one equivalent of 2-{1-[2-(1,3-dimethyl-4-nitro-1H-pyrazol-5-yl)hydrazono]methyl} pyridine (PCHP) ( 3a ) or its analogue 2-{1-[2-(1,3-dimethyl-4-nitro-1H-pyrazol-5-yl)hydrazono]ethyl} pyridine (APHP) ( 3b ) produce corresponding pyridine-hydrazone Schiff base coordination complexes [Pd(PCHP)Cl 2 ] ( 4a ) and [Pd(APHP)Cl 2 ] ( 4b ), respectively. Compounds 4a , b are characterized by elemental analysis, IR spectroscopy, and 1 H NMR. Attempts to crystalize 4b lead to N–C( sp 3 )–E pincer palladacycle [Pd(APHP–H)Cl(DMSO)] ( 5 ). The molecular structures of 5 in the solid state are determined by single crystal X-ray structure analysis. The X-ray crystal structure of 5 shows the existence of the five-membered metallacycle through the coordination of and pyridine N to the palladium center and the cis arrangement between the metalated nitrogen atom and DMSO. The cytotoxicity of the two ligands and palladium(II) complexes 4a and 5 evaluated against K562 human cancer cell line. The corresponding GI50 (50% growth inhibition) values are compared to the cytotoxicity of cisplatin, under the same experimental conditions, and the results indicate inactive ligands and a superior activity to cisplatin for the complexes.