Ruthenium (II) Complexes Based on Phenanthroline-Tetrazole as Possible Anticancer Agents.

Background: The development of platinum-based metal complexes in oncology is limited due to vigorous toxicity and drug resistance. Objectives: This work aimed to study the cytotoxic activity and apoptosis induction of ruthenium complexes in a B16F10 cell line therapy. Methods: We prepared a series of innovative Ru(II) complexes [Ru(Tzphen)(bpy)(dcbpy)]+2 (S1), [Ru(dcbpy)2(Tzphen)]+2 (S2), [Ru(Phen)2(Tzphen)]+2 (S3), [Ru(Tzphen)(bpy)2]+2 (S4), [Ru(dmbpy)2(Tzphen)]+2 (S5) based on 1,10-phenanthroline ligand containing tetrazole and their anticancer properties investigated by cytotoxicity in vitro, reactive oxygen species, apoptosis with annexin V/PI staining method, autophagy, and cell uptake. Results: S1, S2, S3, S4, and S5 complexes showed comparable cytotoxicity activity relative to cisplatin against the B16F10 model. Moreover, intracellular ROS levels increased due to the presence of the complexes. Among the investigated complexes, the cells treated with the S5 complex indicated the highest apoptotic percentage (Q3) of 14.9% compared to the controls. The cell adsorption of the complexes also showed that the S4 and S5 complexes had higher cell adsorption, better internalization, and higher fluorescence light intensity. Conclusions: The present work provides important guidance for designing and using Ru complexes in cancer therapy.

Copper (II) complexes with N, S donor pyrazole-based ligands as anticancer agents.

A group of bidentate nitrogen and sulfur donor pyrazole derivative ligands abbreviated as Na[RNCS(Pz)], Na[RNCS(PzMe2)], Na[RNCS(PzMe3)], Na[RNCS(PzPhMe)], Na[RNCS(PzPh2)], where (R = Et, Ph), and their Cu (II) complexes were synthesized and characterized by spectroscopic and physicochemical methods. The crystal structure of [Cu(PhNCSPzMe3)2] was determined by X-ray crystallography analysis and the results described a distorted square planar coordination geometry for this complex. Also, the cyclic voltammetry investigations indicated that the synthesized copper complex is an electrochemically active species. Moreover, the cytotoxic activity of all of the twenty synthesized compounds was evaluated using MTT assay against the MCF-7 (human breast carcinoma) cell lines, in vitro. Cu (II) complexes indicate significant cytotoxicity against the MCF-7 cell lines as compared with the free ligands. The docking studies showed that the copper complexes have better interactions with EGFR and CDK2 proteins, compared to the free ligands, and most of the studied compounds have a higher value of binding energy relative to the studied controls. The results of QSAR analysis suggest that dipole moment is in direct correlation with the obtained IC50 values, and it strongly impact the anticancer effects generated by the compounds. Our findings suggest that the developed copper complexes can be good candidates for further evaluations as chemotherapeutic agents in the treatment of cancer.

Visible light-driven photocatalytic activity of wide band gap ATiO3 (A = Sr, Zn and Cd) perovskites by lanthanide doping and the formation of a mesoporous heterostructure with ZnS QDs.

Charge carrier recombination and wide band gap energy are still the main challenges in the visible-light-driven photocatalytic applications of titanate perovskites, ATiO3. Herein, three strategies are rationally used to achieve a titanate-based photocatalyst with high photocatalytic performance under visible light. In the first step, SrTiO3, ZnTiO3, and CdTiO3 perovskites were synthesized and their photocatalytic activity was evaluated in the degradation of methylene blue (MB) and bisphenol A (BPA). Then, a dysprosium cation (Dy3+) was doped into an ATiO3 crystalline lattice. Systematic investigations indicate that Dy doping in SrTiO3 and CdTiO3 extends the ligand to metal charge transfer absorption edge to visible wavelengths leading to the activation of doped perovskites under visible light. Higher visible-light-driven photocatalytic performance (73.29% for MB and 52.57% for BPA) and higher total organic carbon (TOC) removal (59.20% for MB and 39.53% for BPA) have been achieved by Dy doped CdTiO3 compared to other photocatalysts. Finally, we prepared a Dy-CdTP/ZnS QD mesoporous type-II heterostructure by the in situ growth of ZnS QDs on a flower-like Dy-CdTP. This design accelerates the separation and transfer of photogenerated electron-hole pairs. The surface area of the Dy-CdTP/ZnS QD heterostructure was ∼11.6 times greater than that of Dy-CdTP, offering a large surface area for the adsorption of organics, and abundant active sites for photocatalytic degradation. Taking advantage of the large surface area and considerable suppressing of the charge carrier recombination, the optimized Dy-CdTP(0.6)/ZnS QD photocatalyst exhibits excellent and stable performance for the degradation of MB (98.25%) and BPA (89.12%) with their considerable mineralization under visible light.

Thermolysis synthesis of pure phase NiO from novel sonochemical synthesized Ni(II) nano metal-organic supramolecular architecture.

Nano-structures of a new supramolecular coordination compound of divalent nickel with the pyrazol (pzH) containing the terminal azide anions, [Ni(pzH)2(N3)2] (1), with discrete molecular architecture (DMA) in solid state was synthesized via sonochemical method. The new nanostructure was characterized by scanning electron microscopy, X-ray powder diffraction, IR, and elemental analysis. Compound 1 was structurally characterized by single crystal X-ray diffraction and the single-crystal X-ray data shows that the coordination number of Ni (II) ions is six, (NiN6), with four N-donor atoms from neutral "pzH" ligands and two N-donors from two terminal azide anions. The supramolecular features in these complexes are guided and controlled by weak directional intermolecular interactions. The structure of the title complex was optimized by density functional theory calculations. Calculated structural parameters and IR spectra for the title complex are consistent with the crystal structure. The NiO nanoparticles were obtained by thermolysis of 1 at 180°C with oleic acid as a surfactant.

Proposed mechanisms for water oxidation by Photosystem II and nanosized manganese oxides.

Plants, algae and cyanobacteria capture sunlight, extracting electrons from H2O to reduce CO2 into sugars while releasing O2 in the oxygenic photosynthetic process. Because of the important role of water oxidation in artificial photosynthesis and many solar fuel systems, understanding the structure and function of this unique biological catalyst forms a requisite research field. Herein the structure of the water-oxidizing complex and its ligand environment are described with reference to the 1.9Å resolution X-ray-derived crystallographic model of the water-oxidizing complex from the cyanobacterium Thermosynechococcus vulcanus. Proposed mechanisms for water oxidation by Photosystem II and nanosized manganese oxides are also reviewed and discussed in the paper.

Ultrasound-assisted fabrication of a novel nickel(II)-bis-pyrazolyl borate two-nuclear discrete nano-structured coordination compound.

Ultrasound was used to synthesize nano-structures of [Ni(bpzB)2]2(1), a new two-nuclear discrete-coordination compound of divalent nickel with bis-pyrazolyl borate(bpzB). The nanostructure was characterized by scanning electron microscopy, X-ray powder diffraction, infrared, and elemental analysis. The single-crystal X-ray data show that the coordination number of Ni(II) ions is four (Ni1N4 and Ni2N4) with square planar geometry. The supramolecular features in these complexes are guided and controlled by weak directional intermolecular interactions. The discrete molecules interact with each other through labile interactions, creating a 3D supramolecular framework.

Sonochemical synthesis of Pr-doped ZnO nanoparticles for sonocatalytic degradation of Acid Red 17.

Undoped and Pr-doped ZnO nanoparticles were prepared using a simple sonochemical method, and their sonocatalytic activity was investigated toward degradation of Acid Red 17 (AR17) under ultrasonic (US) irradiation. Synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques. The extent of sonocatalytic degradation was higher compared with sonolysis alone. The decolorization efficiency of sonolysis alone, sonocatalysis with undoped ZnO and 5% Pr-doped ZnO was 24%, 46% and 100% within reaction time of 70min, respectively. Sonocatalytic degradation of AR17 increased with increasing the amount of dopant and catalyst dosage and decreasing initial dye concentration. Natural pH was favored the sonocatalytic degradation of AR17. With the addition of chloride, carbonate and sulfate as radical scavengers, the decolorization efficiency was decreased from 100% to 65%, 71% and 89% at the reaction time of 70min, respectively, indicating that the controlling mechanism of sonochemical degradation of AR17 is the free radicals (not pyrolysis). The addition of peroxydisulfate and hydrogen peroxide as enhancer improved the degradation efficiency from 79% to 85% and 93% at the reaction time of 50min, respectively. The result showed good reusability of the synthesized sonocatalyst.

1,1'-Bis(tert-butyl-dimethyl-sil-yl)ferrocene.

The asymmetric unit of the title compound, [Fe(C11H19Si)2], consists of one half of a ferrocene derivative. The Fe(II) atom lies on a twofold rotation axis, giving an eclipsed conformation for the cyclo-penta-dienyl ligands. No significant inter-molecular inter-actions are observed in the crystal structure.

Dichloridobis(4-methyl-3,5-diphenyl-1H-pyrazole-κN)copper(II).

The asymmetric unit of the title compound, [CuCl(2)(C(16)H(14)N(2))(2)], comprises half of the complex. The Cu(II) atom lies on a crystallographic twofold rotation axis and shows a significantly distorted tetra-hedral coordination geometry. The dihedral angle between the phenyl rings is 74.3 (2)°. The crystal structure is stabilized by inter-molecular π-π inter-actions [centroid-centroid distances = 3.635 (2)-3.803 (3) Å].

Bis[bis-(3,5-dimethyl-1H-pyrazol-1-yl)-borato]cobalt(II).

The asymmetric unit of the title compound, [Co(C(10)H(16)BN(4))(2)], comprises one unit of the complex. The geometry around the Co(II) ion is a distorted tetra-hedron. The dihedral angles between the pyrazole rings in the two ligands are 47.19 (15) and 47.20 (16)°, while that between the coordination planes is 79.77 (7)°.

Bis(4-methyl-3,5-diphenyl-1H-pyrazole-κN)silver(I) nitrate.

In the title complex, [Ag(C(16)H(14)N(2))(2)]NO(3), the geometry around the Ag(I) ion is T-shaped with two short Ag-N bonds to the pyrazole ligand and one long Ag-O bond to the nitrate anion. The crystal structure is stabilized by inter-molecular N-H⋯O, C-H⋯O and C-H⋯π inter-actions.

Chlorido(1H-imidazole-κN)bis-(triphenyl-phosphane-κP)copper(I).

In the title complex, [CuCl(C(3)H(4)N(2))(C(18)H(15)P)(2)], the coordination geometry around Cu(I) is distorted tetra-hedral formed by two triphenyl-phosphane ligands, an imidazole ligand and a chloride group. An intra-molecular C-H⋯Cl inter-action occurs. The crystal packing is stabilized by inter-molecular N-H⋯Cl hydrogen bonds, which form an extended chain parallel to [010].

trans-Bis(thio-cyanato-κN)tetra-kis-(3,4,5-trimethyl-1H-pyrazole-κN)nickel(II)-3,4,5-trimethyl-1H-pyrazole (1/1).

In the title compound, [Ni(NCS)(2)(C(6)H(10)N(2))(4)]·C(6)H(10)N(2), the asymmetric unit comprises a Ni(II) complex and a co-crystallised mol-ecule of 3,4,5-trimethyl-1H-pyrazole (PzMe(3)). The Ni(II) atom is coordinated by four PzMe(3) mol-ecules and two thio-cyanate anions to define a trans N(4)S(2) distorted octa-hedral geometry. A number of intra-molecular N-H⋯N, N-H⋯S and C-H⋯N inter-actions contribute to the stability of the complex. The crystal structure is stabilized by inter-molecular N-H⋯S inter-actions, which link neighbouring mol-ecules into chains along the a axis.

Dibromidotetra-kis(1H-indazole-κN)copper(II).

The Cu atom in the title compound, [CuBr(2)(C(7)H(6)N(2))(4)], is surrounded by four N-heterocycles that define an N(4) square-planar geometry. The coordination geometry is distorted towards an elongated octa-hedron owing to the presence of the two Br(-) anions, which are located at about 3 Šabove and below the square plane. There are two independent molecules in the asymmetric unit, each with their Cu atom lying on an inversion centre.