ANALYTICAL AND INORGANIC STUDIES OF NEW ANTITUMOR PALLADIUM(II), RUTHENIUM(II) AND PLATINUM(IV) COMPLEXES

Abstract

Five rapid, simple, sensitive and validated spectrophotometric method has been described for the determination of palladium(II) using 3,4diaminobenzoic acid(DABA)(1),4-chloro–o-phenylenediamine (CPDA)(2) and 2-hydrazino pyridine (hzpy)(3) and both ruthenium(III)(4) and platinum(IV)(5) using 4-chloro–o-phenylenediamine(CPDA). The complexes product was quantitatively measured at 760 nm(1), 545nm(2), 510 nm(3), 560nm(4) and 715nm(5) and the reaction conditions were studied and optimized. The stoichiometry and the stability constant of the purple colored complexes have been determined spectrophotometrically in aqueous solution at 25 oC using Job’s continuous variation and the molar ratio methods. The complexes have The molar ratios (M:L) : 1:2(1), 1:2(2), 1:1(3), 1:1(4),1:2(5) and Beer’s plot was linear in the concentration ranges 1.06- 8.48(1), 2.21-10.6(2), 1.06-9.00(3), 2.00-12,36(4) and 1.95-27.30(5) μg/mL with corresponding molar absorptivity 1.32×104 (1), 2.89×103 (2), 2.60×103 (3), 1.91×103 , 2.13×103 (5) , L/mol.cm. The limits of detection and Sandell’s sensitivity were evaluated. The accuracy was evaluated as the % recovery 99.66-101.70(1), 98.09-102.20(2), 97.55-102.58(3), 97.79- 102.36(4) and 98.02-102.88(5) precision was evaluated as RSD% 0.3- 1.13(1), 0.3-1.13(2), 0.04-0.41(3), 0.06-0.51(4) and 0.04-0.23(5) using inter day and intraday analyses of multiple samples. The effect of various diverse ions on the determination of Pd(II), Ru(III) and Pt(IV) using the above ligands have been investigated. The solid complexes of Pd(II), Ru(II) and Pt(IV) complexes with DABA, CPDA and hzpy as well as their ternary complexes with oxalaic acid, maleic acid and sodium pyrophosphate as secondary ligands were synthesized and characterized using elemental analysis, IR, Mass and UV-Vis spectrometry, magnetic moments and thermal analysis. The structures of the complexes were geometrically optimized using PM3 semiemperical method and Quantum chemical parameters of organic compounds are obtained from calculations, such as the energy of the highest occupied molecular orbital, EHOMO, energy of the lowest unoccupied molecular orbital, ELUMO. Additional parameters, such as separation energies (ΔE), absolute electronegativity (χ), chemical potentials (Pi), absolute hardness (η), absolute softness (σ), global electrophilicity (ω), global softness (S) and additional electronic charge (ΔNmax) have been calculated. The complexes were screened for their cytotoxicity against HEPG2 (liver carcinoma cell line), HEP2 (larynx carcinoma cell line), HELA (cervical carcinoma cell line), HCT116 (colon carcinoma cell line) and MCF7 (breast carcinoma cell line). The IC50 (The half maximal inhibitory concentration) of some selected complexes were evaluated and compared with doxorubicin drug as reference.