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The effect of modification of polycrystalline platinum by Tl adatoms on the electrocatalytic properties of the electrodes towards the oxidation of monosaccharides was investigated. Significant electrocatalytic effect towards glucose and methylglucoside oxidation was observed on Pt-Tl electrodes as displayed by an enhancement of the oxidation current densities. Different carboxylic acids produced by the electrolysis of carbohydrates were analyzed by ionic chromatography. The electrooxidation of glucose on Pt-Tl gave gluconic and keto-gluconic acids, successively. When the anomeric carbon is protected (methylglucoside), the first oxidation step of the monosaccharide was carried out on the primary alcohol following the same path as that of methanol oxidation.

The molecular structure, the Natural Bond orbital (NBO) and the Time Dependent-DFT of both isomers cis or γ-Cl and trans or δ-Cl of RuCl 2 (L) 2 , where L stands respectively for 2-phenylazopyridine (Azpy), 2,4-dimethyl-6-[phenylazo]pyridine (Dazpy), 2-[(3,5-dimethylphenyl)azopyridine] (Mazpy) and 2-pyridylazonaphtol (Nazpy) were calculated with DFT method at B3LYP/LANL2DZ level. The prediction of the frontier orbitals (Highest Occupied Molecular Orbital or HOMO and Lowest Unoccupied Molecular Orbital or LUMO) shows that the most active complexes suitable for electronic reactions are admitted to be the trans isomers. Moreover, δ-RuCl 2 (Azpy) 2 is discovered to react more actively as photo-sensitizer since its energy gap is the minimum. Besides, electronic structures of all complexes through NBO calculation indicate that Ru-N bonds are made of delocalization of occupancies from lone pair orbital of N atoms to the ruthenium. Moreover, Ru was assumed to have almost the same charge regardless the structure of the azopyridine ligands in the complex indicating that the ligands provide only a steric effect that is responsible for the ruthenium's selectivity. Concerning the transition state, NBO analysis also highlights that the transition LP(Ru)π*(N 1 -N 2 ) does correspond to t 2g π*(L). This transition is assumed to correspond to Metal to Ligand Charge Transfer (MLCT) that is responsible for the photo-sensitiveness of the metallic complex. Besides, TDDFT calculation of complexes showed that δ-RuCl 2 (Nazpy) 2 displays the largest band during the absorption. For that reason, it is admitted to be the best photosensitizer due to a large system of conjugation provided by Nazpy ligand.

A series of ruthenium azopyridine complexes have recently been investigated due to their potential cytotoxic activities against renal cancer (A498), lung cancer (H226), ovarian cancer (IGROV), breast cancer (MCF-7) and colon cancer (WIDR). Thus, in order to predict the cytotoxic potentials of these compounds, quantitative structure-activity relationship studies were carried out using the methods of quantum chemistry. Five Quantitative Structure Activity Relationship (QSAR) models were obtained from the determined quantum descriptors and the different activities. The models present the following Moreover, the charge of the ligand is the priority descriptor for the prediction of the cytotoxicity of the compounds studied. Furthermore, QSAR models developed are statistically significant and predictive, and could be used for the design and synthesis of new anti-cancer molecules.