Sahar I. Mostafa

Complexes of 2-hydroxynaphthalene-1-carboxaldehyde with transition metal ions

New 2-hydroxynaphthalene-1-carboxaldehyde (Hhnca) complexes M(hnca)3 (M = Cr, Fe,Ru or Rh), M(hnca)2 (M=Co, Ni,Cu or Pd),trans-MO2(hnca)2(M = Os, U), [Ag(hnca)2]-, ReO(PPh3)(hnca)2I, [Cu(py)2(hnca)]+, [Ni(bipy)2(hnca)]+ and [CoL2(hnca)]+ (L=bipy or py2) are described. Their i.r., Raman, 1H-n.m.r. and electronic spectra and magnetic moments have been measured and are discussed. The proton–ligand formation constant (pK*_A) of the ligand has been determined potentiometrically.

Synthesis, characterization and antineoplastic activity of 5-chloro-2,3-dihydroxypyridine transition metal complexes

Synthetic procedures are described that allow access to cis-[Mo2O5(cdhp)2]2−, cis-[W2O5(Hcdhp)2], trans-[OsO2(cdhp)2]2−, trans-[UO2(Hcdhp)2], [ReO(PPh3)(Hcdhp)2]X (X  = Cl, I), [ReO2(cdhp)2]−, [M(PPh3)2(cdhp)], [M(bpy)(cdhp)] (M(II)  = Pd, Pt), [Ru(YPh3)2(Hcdhp)2] (Y  = P, As), [Rh(Hcdhp)2Cl(H2O)], [Rh(PPh3)2(Hcdhp)2]ClO4 and [Ir(bpy)(cdhp)Cl2], where Hcdhp, cdhp are the deprotonated monoanion of 5-chloro-3-hydroxypyrid-2-one and dianion of 5-chloro-2,3-dihydroxypyridine, respectively. These complexes were characterized by their Raman, IR, 1H NMR, electronic and mass spectra, conductivity, magnetic and thermal measurements. H2cdhp, cis-K2[Mo2O5(cdhp)2], [Pd(bpy)(cdhp)] display a significant antineoplastic activity against Ehrlich ascites tumor cells (EAC).

Ruthenium(II) 2-hydroxybenzophenone N(4)-substituted thiosemicarbazone complexes

New ruthenium(II) complexes with 2-hydroxybenzophenone N(4)-substituted (Me, Ph and/or piperidyl) thiosemicarbazones have been prepared and characterised by elemental analysis, molar conductivity, thermal analysis, spectroscopy (i.r., 1H-n.m.r. and u.v.–vis.) and by cyclic voltammetry. The thiosemicarbazones coordinate to ruthenium(II) as mononegative tridentate ligands via the deprotonated hydroxyl group, N1 nitrogen and thione sulphur centres. The redox properties, nature of the electrode processes and the stability of the complexes towards oxidation in CH2Cl2 are discussed. The change in the E1/2 values of the complexes can be related to the basicity of the N(4)-substituents. All the complexes display an irreversible one-electron charge-transfer couple in the potential range studied.

Synthesis, Spectral, Magnetic and Thermal Studies of 1-Phenylacetyl-4-Phenyl-3-Thiosemicarbazide Complexes

Abstract Complexes of 1-phenylacetyl-4-phenyl-3-thiosemicarbazide (H2PAPTS) with Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Cd(II) and Hg(II) have been prepared and characterized on the basis of chemical, thermal (TG, DTA) analyses, spectral (IR, 1H NMR, UV-Vis.), magnetic moment and molar conductivity measurements. IR and 1H NMR spectral data show that H2PAPTS behaves as a neutral bidentate, mononegative bidentate or binegative tetradentate ligand. All the reported complexes are non-electrolytes and different stereochemistries are proposed for the Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Pd(II) complexes according to their magnetic and spectral measurements. The thermal decomposition of the complexes (Co(HPAPTS)(OAc)] and [Cd(HPAPTS)(OAc)(H2O)2] suggests a mechanism for their degradation. The [Fe(PAPTS)Cl(H20)] complex was found to function as a one-electron stoichiometric oxidant towards primary and secondary alcohols.

COMPLEXES OF 2,5-DIHYDROXY-1,4-BENZOQUINONE AND CHLORANILIC ACID WITH SECOND AND THIRD ROW TRANSITION ELEMENTS

The synthesis of new 2,5-dihydroxy-1,4-benzoquinone (H2DHBQ) and chloranilic acid (H2CA) complexes cis-[Mo2O5L2]2− (L = DHBQ, CA), [W2O5(DHBQ)2]2−, [WO2(CA)2]2−, trans-[UO2(DHBQ)]·H2O, and trans-[UO2(CA)2]2− is described. Raman, i.r., 1H and 13C n.m.r spectra of the ligands and their complexes are reported and their structures discussed.

Ligational and analytical applications of a uracil derivative toward some transition metal ions

New complexes of the uracil derivative (5,6-diamino-2,4-dihydroxypyrimidine) hemisulfate (H2AHP) having the formulas [Fe(HAHP)2Cl(H2O)]H2O, [M(HAHP)2(H2O)2]MeOH (M = Co, Ni), [Cu(HAHP)(H2AHP)(H2O)Cl]H2O, [Zn(HAHP)2]H2O, [MoO2(HAHP)2]4H2O, [Ru(HAHP)2(H2O)2], [Rh(HAHP)2(H2O)Cl], [Pd(AHP)n]H2O, [Ag2(H2AHP)(H2O)4](NO3)2 and [Au(H2AHP)Cl3]H2O have been characterized by IR, electronic, 1HNMR and mass spectral studies, magnetic and thermal measurements. Cyclic voltammetry was used to study the electrochemical behavior of the Ru and MoO2 complexes. Formation of complexes in solution was studied pH metrically and their stability constants clearly indicate that the divalent metal ions have the order: Pd(II) > Cu(II) > Co(II) ∼ Ni(II) > Zn(II) while Ru(III) > Rh(III) > Au(III) > Fe(III) is the order of the trivalent ions. A flotation procedure for the separation of Ag(I), Pd(II), Pt(IV) and Au(III) individually or in combination has been described. The maximum separation of each analyte is achieved using 2 × 10−4 M H2AHP and 1 × 10−3 M oleic acid. The procedure is applied to some synthetic mixtures and the separation mechanism is proposed.

Bone Repair Stimulation in Rat Mandible by New Chitosan Silver(I) Complexes

Two new chitosan silver(I) complexes, [Ag(2CS)(H2O)(NO3)] and [Ag(2CS)(ahmp)(H2O)] (CS = chitosan, Hahmp = 4-amino-6-hydroxy-2-mercaptopyrimidine) were synthesized and characterized on the basis of elemental analysis, spectral (FT-IR and solid-state 13C-NMR), morphological (SEM, matrix analysis, XRD, and XRPE), and thermal measurements. Chitosan behaves as a neutral ligand, coordinates Ag(I) through half of amino nitrogen centers, with the pendant glucose amine hydroxy functionality playing no role in coordination, while 4-amino-6-hydroxy-2-mercaptopyrimidine functions as mononegative bidentate, chelating through the deprotonated cyclic nitrogen and thione sulfur atoms. [Ag(2CS)(ahmp)(H2O)] displays a significant potential bone regenerator in rat mandible. Forty male rats were divided into two groups: bone defect (control) and bone defect with [Ag(2CS)(ahmp)(H2O)] (treated). The bone defects were stained with hematoxylin and eosin, and Massons trichrome for histological analysis. The treated group shows faster and well organized bone formation in the defect in comparison to the control group which shows little new bone trabeculae and wide marrow cavities.

Synthesis, spectral characterization, and anticancer activity of 6-methylpyridine-2-carbaldehdyethiosemicarbazone and its complexes; crystal structure and DFT calculations of [Pd(mpyptsc)Cl]·DMSO

Synthesis and characterization of new complexes of 6-methylpyridine-2-carbaldehydethiosemicarbazone (Hmpytsc) and 6-methylpyridine-2-carbaldehyde-N(4)-phenylthiosemicarbazone (Hmpyptsc) with [VO2L], [Zn(HL)Cl2], [Ru(PPh3)2L2], and [MLCl] (M(II) = Pd, Pt; HL = Hmpytsc, Hmpyptsc) are reported. Their structures are discussed on the basis of IR, Raman, UV–vis, NMR (1H, 13C, and 31P), and mass spectroscopic data, as well as elemental analysis and molar conductivity. In the X-ray crystal structure of the square-planar [Pd(mpyptsc)Cl]·DMSO, mpyptsc− is coordinated to Pd(II) in a tridentate manner through pyridyl N, azomethine N, and thiol S, and the fourth coordination site is occupied by a chloride. A theoretical study on [Pd(mpyptsc)Cl]·DMSO was undertaken through DFT conformational analysis. The in vitro cytotoxic activity has been evaluated against human colon cancer (HCT116) and prostate cancer (DU145) cell lines. Hmpyptsc and [Zn(Hmpyptsc)Cl2] were most active with mean IC50 values of 3.32 and 2.60 (HCT116), and 3.60 and 3.10 (DU145) μM, respectively. Graphical Abstract New complexes of 6-methylpyridine-2-carbaldehydethiosemicarbazone (Hmpytsc) and 6-methylpyridine-2-carbaldehyde-N(4)-phenylthiosemicarbazone (Hmpyptsc) and crystal structure of [Pd(mpyptsc)Cl]·DMSO are reported. Hmpyptsc and its complexes were tested against human colon cancer (HCT116) and prostate cancer (DU145) cell lines.

Development of New Potential Anticancer Metal Complexes Derived from 2-Hydrazinobenzothiazole

BACKGROUND Due to the bad side effects of clinically approved anticancer drugs there is a great need to explore and develop new metal-based anticancer drug molecules of high efficiency with less or no side effects. OBJECTIVE To synthesize new metal complexes of 2-hydrazinobenzothiazole (hbt) and to investigate their potential anticancer characteristics. METHOD New five complexes; [VO(hbt)2SO4].4H2O (1), [Ru(hbt)2Cl3(H2O)] (2), [M(hbt)2Cl2] [M(II) = Pd (3), Pt (4)] and [Ag(hbt)2].NO3 (5) were prepared and their structure was investigated by means of FT-IR, 1H NMR, ESI-MS and UV-Vis spectra, elemental and thermal analysis, magnetic and molar conductance measurements. The ligand and its complexes were examined as anticancer agents against Ehrlich ascites carcinoma (EAC) and human cancer cells (hepatocellular carcinoma Hep-G2, mammary gland breast cancer MCF-7 and colorectal carcinoma HCT-116). This feature is further supported by the DNA-metal complexes binding ability. In addition, anti-oxidation activity of the complexes was investigated. CONCLUSION Complex (5) showed the highest antioxidation and anticancer activities.

Cellulose derivatives modified by sodium tellurate and a chromium(III) tellurate complex

A novel cellulose (Cell) derivative, sodium-tellurato (Cell-TeO(OH)4(ONa)/Cell-Cl), has been synthesized from the reaction of 6-chloro-6-deoxycellulose (Cell-Cl) with telluric acid in the presence of sodium hydroxide. The subsequent reaction of this polymeric material with chromium(III) in aqueous solution yields the [Cr(Cell-TeO3(OH)3/Cell-Cl)(Cell-TeO2(OH)4/Cell-Cl)(H2O)3] complex. The molecular structures and morphology of the new polymer and the Cr(III) complex have been examined using elemental analysis, solid-state (13)C NMR, UV-vis, XRD and FTIR spectroscopy, and SEM-EDX, TGA and magnetic measurements. The results are considered to be consistent with the formulations proposed. The deprotonation constants of the modified cellulose and the stability constant of the Cr(III) complex have been determined by pH-metric measurements.