Ab Initio-Based Global Potential Energy Surface and Reaction Dynamics for H2S + C.

Dynamics of the reaction of hydrogen sulfide, H2S(X1A1), with ground-state atomic carbon, C(3Pj), was investigated over the interpolated ab initio-based potential energy surface using the quasi-classical trajectory (QCT) simulation. The reaction probability and total reactive cross section were calculated at a wide range of collision energies from 2.6 to 78.8 kJ mol-1. The total rate constant of the reaction was calculated using collision theory. The energy distribution for the formation of main products (HCS/HSC + H) was also investigated. At 44.6 kJ mol-1 collision energy, approximately 39.5 and 12% of the total available energy were released to translational and rotational energy levels of the HCS + H products, respectively, while for HSC + H, these values were found to be about 61.6 and 25.7% of the total available energy. The remaining total energy was deposited in the vibrational modes of the products.

A new mononuclear zinc(II) complex: Crystal structure, DNA- and BSA-binding, and molecular modeling; in vitro cytotoxicity of the Zn(II) complex and its nanocomplex.

A new mononuclear Zn(II) complex, [Zn(Me2bpy)3](PF6)2·DMF (Me2bpy = 4,4'-dimethyl-2,2'-bipyridine), has been synthesized and fully characterized. Binding studies of the Zn(II) complex with fish sperm DNA (FS-DNA) and bovine serum albumine (BSA) were investigated using cyclic voltammetry, UV-Vis and fluorescence spectroscopies. The results showed that the majority of the interaction modes between the Zn(II) complex and DNA is a combination of the electrostatic and minor groove bindings, and the microenvironment of three aromatic amino acids residues is changed due to the interaction of the Zn(II) complex with BSA. In vitro cytotoxicity studies of the Zn(II) complex and its nanocomplex against three human carcinoma cell lines (MCF-7, A-549, and HT-29) using an MTT assay indicated that the cytotoxicity of both compounds against HT-29 and MCF-7 is higher than A-549. Moreover, the results clearly demonstrated that the aqueous colloid of the Zn(II) nanocomplex is more effective than the complex solution against HT-29 and MCF-7 cells under the same experimental conditions. The microscopic analyses of the cancer cells showed that the Zn(II) complex apparently induces the cell apoptosis. The interactions of the Zn(II) complex with DNA and BSA were also modeled using molecular docking. The results are in good agreement with the experimental findings.

The first palladium(iv) aryldiazenido complex: relevance for C-C coupling.

Overall two-electron oxidative addition of the aryldiazonium cation para-methoxybenzenediazonium (pmbd+) to [(Tp*)PdIIMe2]- (Tp*- = hydridotris-(3,5-dimethylpyrazolyl)borate) produces the first characterized palladium(iv) aryldiazenido complex, [(Tp*)PdIVMe2(pmbd)] (pmbd- = para-methoxybenzenediazenido). Thermolysis in benzene forms a mixture of products that contains [(Tp*)PdIVMe3] and the C-C coupled product, 4,4'-dimethoxybiphenyl. The use of acetone as the thermolysis solvent changes the product distribution towards the formation of anisole. While some involvement of two-electron pathways in the decomposition cannot be ruled out, radicals, through one-electron steps, are involved in the major pathways for decomposition. The involvement of radicals is confirmed by the solvent dependent nature of the product distribution and by observing that the added N-tert-butyl-α-phenylnitrone efficiently traps aryl radicals.

Preparation, characterization and solid-state emission of metal complex-cloisite nanohybrids (MC-C, M = Ru (II) and Cu (II)).

The presence of Na(+) in the Cloisite Na(+) mineral allows modification of its interlayer space to achieve a better compatibility with the host matrix and ion-exchange with a cationic metal complex. The aim of this research is to prepare two new metal complex-Cloisite (MC-C) nanohybrids using reaction of Cloisite Na(+) with the cationic Ru (II) and Cu (II) complexes, [Ru (tpy) 2] (2+) and [Cu (Pir) (phen) (H2O) 2](+), in an aqueous solution for the first time. The X-ray diffraction (XRD) analysis of the modified clays has shown an increase in its interlayer distance as compared to the unmodified Cloisite Na(+). The positions of the basal reflections in the XRD patterns of the modified clays were shifted to a higher d value indicating the expansion in their interlayer distances. The field-emission scanning electron microscopy has shown a homogeneous morphology for the modified clays. The thermal behavior of these novel hybrid materials was also investigated by thermogravimetric analysis. The solid state fluorescence spectra of the modified clays have shown that both cationic complexes exhibit a significant fluorescence emission at room temperature when intercalated into Cloisite.