Acid–base equilibria of the aqua adducts of Ru(II) arene complexes with functionalised pyridines

Acid?Cbase equilibria of the aqua adducts of Ru(II) arene complexes, general formulae [(??⁶-p-cymene)Ru (L^1?3)Cl₂] where L¹?=?3-acetylpyridine (1), L²?=?4-acetylpyridine (2) and L³?=?2-amino-5-chloropyridine (3), then [(??⁶-p-cymene)Ru(HL⁴)Cl₂] with HL⁴?=?isonicotinic acid (4); [(??⁶-p-cymene)Ru(HL^5?8)Cl] where H₂L⁵?=?2,3-pyridine dicarboxylic acid (5), H₂L⁶?=?2,4-pyridine dicarboxylic acid (6), H₂L⁷?=?2,5-pyridine dicarboxylic acid (7) and H₂L⁸?=?2,6-pyridine dicarboxylic acid (8) have been studied. pK _a values were determined by potentiometry at 25?°C and constant ionic strength of 0.1?M NaNO₃. The assumed equilibria were confirmed by UV and ¹H-NMR spectroscopy.     

Application of generalized diagonal dominance in wireless sensor network optimization problems

The recent application of the diagonal dominance in the development of the optimization algorithms in the wireless sensor networks design, has been done by Yuan and Yu (2006) [14], extended in Yu et al. (2006) [9], and surveyed in Machado and Tekinay [11]. In this paper, we will use the concept of generalized diagonal dominance, to improve the obtained results regarding the power control game, in three directions. We also discuss the applicability of such improvements.     

The Chemi-Ionization Processes in Slow Collisions of Rydberg Atoms with Ground State Atoms: Mechanism and Applications

In this article the history and the current state of research of the chemi-ionization processes in atom–Rydberg atom collisions is presented. The principal assumptions of the model of such processes based on the dipole resonance mechanism, as well as the problems of stochastic ionization in atom–Rydberg atom collisions, are exposed. The properties of the collision kinetics in atom beams of various types used in contemporary experimentations are briefly described. Results of the calculation of the chemi-ionization rate coefficients are given and discussed for the range of the principal quantum number values 5 ≤ n ≤ 25. The role of the chemi-ionization processes in astrophysical and laboratory low-temperature plasmas, and the contemporary methods of their investigation are described. Also the directions of further research of chemi-ionization processes are discussed in this article.     

Enhancement of dissociation by metal-support interaction: reaction of NO on Rh supported by ceria films of controlled oxidation state

Highly oriented thin films of cerium oxide with variable ratio of Ce³⁺/Ce⁴⁺ were grown on Ru(0 0 0 1) single crystal surface and loaded with a fixed, low coverage of Rh. The chemisorption of NO on the resulting model catalyst was studied by soft X-ray photoemission which yielded the relative quantities of N containing species on the surface as a function of temperature, and by thermal desorption which yielded the relative yields of NO and N₂ desorbed. It is found that the ability of the reduced Rh clusters to dissociate NO depends upon the oxidation state of the ceria upon which it is deposited, and for highly reduced ceria surfaces effectively 100% of Rh-adsorbed NO dissociates by 350 K. Possible causes of this surprising behavior are discussed.     

Influence of the Mobile-Phase Modifier on the Retention of Some para-Substituted Amides; Correlation with Compound Lipophilicity

JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic behavior of para-substituted amides of α-phenylacetic, benzoic, propanoic, and 2,2-dimethylpropanoic acid...     

Common fixed point theorems for weakly compatible quasi contraction mappings

Summary Recently, Pathak [13] has made an extension of the notion of compatibility to weak compatibility, and extended the coincidence theorem for compatible mappings in Kaneko and Sessa [11] to weakly compatible mappings [13]. In the present paper, we define a new class of weakly compatible mappings (Definition 4) and prove some common fixed point theorems for these mappings, which satisfy Condition (2) below. Although our main theorem is formulated for weakly compatible mappings, its corresponding formulation for commutative mappings is also a new result, thus presenting a generalization of some theorems of Fisher, Das and Naik, Khan and Kubiaczyk, Reich, Ćirić and Rhoades and Watson.     

Photochemistry of β,γ-unsaturated 5,10-seco-steroidal ketones

UV irradiation of the β,γ-unsaturated 5,10-seco-steroidal ketones 1 and 2 in dioxane or isopropanol resulted in Z/E isomerization, while similar irradiation in acetone effected, besides, epoxidation (in the presence of air) and addition of solvent to the olefinic double bond.