Synthesis and Properties of Mixed Ligand Complexes of Diorganotin(IV): Part(VII) – Synthesis and Characterisation of Some Antibacterial Dibenzoylmethane Diorganotin(IV)‐O‐alkyl Trithiophosphates

A series of some new mixed ligand complexes have been synthesized with an objective for evaluation as antimicrobials. Reactions of diorganotin(IV) dichloride with dibenzoyl methane and O‐alkyl trithiophosphates in a 1:1:1 molar ratio in refluxing benzene yield products of the type [PhCOCHCOPh]R₂Sn‐[SSH(S)POR'] [where R = Me, Bu, Ph; R' = Me, Et, Prⁱ, Buⁱ, Ph]. The newly synthesized complexes are light yellow colored crystalline solids, non‐volatile, soluble in common organic solvents, monomeric in nature and highly sensitive towards atmospheric moisture. These complexes are characterized by elemental analysis, IR and multinuclear NMR (¹H, ³¹P and ¹¹⁹Sn) spectral studies. Spectral studies of these complexes indicate that dibenzoyl methane and O‐alkyl trithiophosphate moieties are bidentate and the central tin atom is hexacoordinated in nature. A few of these compounds were tested for their antibacterial activity using standard drugs.     

Density, ultrasonic velocity, surface tension, excess volume and viscosity of quaternary fluid solutions

Density, ultrasonic velocity, surface tension, excess volume and viscosity of quaternary non-electrolyte solution n-pentane+tolune+n-heptane+cyclohexane has been experimentally determined at 25 °C over a wide range of composition. Assuming a quaternary fluid solution to be made of six binaries, a statistical approach of Prigogine–Flory–Patterson (PFP) theory has been extended to develop the expressions for dynamic viscosity, surface tension excess volume and ultrasonic velocity of quaternary fluid system. A reasonable agreement has been achieved between theory and experiment. An attempt has also bee made to explain the nature of molecular interactions involved in the light of excess thermodynamic functions whose sign and magnitude depend upon the chain length and size of the component fluids and also studied the role of order breakers (toluene and cyclohexane) on these properties.     

Privacy and pricing personal information

The issues we address here are – How should a firm (e.g. Internet service provider (ISP)) that is capable of collecting personal information (browsing information, purchase history, etc.) about consumers, price its service, given that consumers vary in their valuation for privacy, and also vary in terms of the value of their personal information to a third party (firms that need consumer information)? Should the firm have a blanket policy of never collecting, or a policy of always collecting and revealing information? Surprisingly we find that in some cases the collector of information may be no worse off in the asymmetric information case than in the full information case. The paper provides a justification for the strategy of some firms such as ISP’s which never collect information and also for the strategy of other firms, like grocery stores that do. We also find that it is non-optimal for the firm to design contracts where the consumer can choose an intermediate level of privacy.     

Laser induced optoacoustic spectroscopy of benzil: Evaluation of structural volume change upon photoisomerization

The cis-skew to trans-planar photoisomerization of benzil in the photoexcited state was studied by laser-induced optoacoustic spectroscopy (LIOAS) in a series of normal alkane solvents at room temperature. The structural volume change due to the photoisomerization process has been estimated and compared with the same calculated from the optimized skew and trans structures. The magnitude of the structural volume change is estimated to be 22.9 ± 1.2 mL/mol. This study reveals that an expansion in volume occurs during the photoinduced isomerization process. In non-polar alkane solvents, the estimated volume change has been argued to be free from electrostrictional contribution.     

Two (Z)‐N‐aryl‐3‐benzylideneisoindolin‐1‐ones

Two isoindolin‐1‐one derivatives, (Z)‐3‐benzyl­idene‐N‐phenyl­isoindolin‐1‐one, C₂₁H₁₅NO, (II), and (Z)‐3‐benzyl­idene‐N‐(4‐methoxy­phenyl)­isoindolin‐1‐one, C₂₂H₁₇NO₂, (III), were synthesized by the palladium‐catalysed heteroannulation. The mol­ecules of both compounds have a Z configuration. The interplanar angles between the five‐ and six‐membered rings of the isoindolinone moiety in (II) and (III) are 1.66 (11) and 2.26 (7)°, respectively. The phenyl rings at the N‐position in (II) and (III) are twisted out of the C₄N ring plane by 62.77 (11) and 67.10 (7)°, respectively. The substitutions at the N and C‐3 positions of the isoindolinone system have little influence on the molecular dimensions of the resulting compounds.     

The Quantum-Classical Comparison of the Arrival-Time Distribution Through the Probability Current

We consider the arrival time distribution defined through the quantum probability current for a Gaussian wave packet representing free particles in quantum mechanics in order to explore the issue of the classical limit of arrival time. We formulate the classical analogue of the arrival time distribution for an ensemble of free particles represented by a phase space distribution function evolving under the classical Liouville's equation. The classical probability current so constructed matches with the quantum probability current in the limit of minimum uncertainty. Further, it is possible to show in general that smooth transitions from the quantum mechanical probability current and the mean arrival time to their respective classical values are obtained in the limit of large mass of the particles.     

Simple one‐pot conversion of organic compounds by hydrogen peroxide activated by ruthenium(III) chloride: organic conversions by hydrogen peroxide in the presence of ruthenium(III)

The aromatic compounds p‐nitrobenzaldehyde, p‐hydroxybenzaldehyde, naphthalene, toluene, catechol, quinol, aniline and toluidine dissolved in aqueous acetic acid or aqueous medium were oxidized in quantitative to good yields by 50% H₂O₂ in the presence of traces of RuCl₃ (～10^?8 mol; substrate/catalyst ratio 1488:1 to 341 250:1). Conditions for highest yields, in the most economical way, were obtained. Higher catalyst concentrations decrease the yield. Oxidation in aromatic aldehydes is selective at the aldehydic group only. In the case of hydrocarbons, oxidation results in the introduction of a hydroxyl group with >85% (in the case of toluene) selectivity for the ortho position. Formation of low‐molecular‐weight polyaniline was reduced to 10%, along with 90% formation of higher molecular weight polyaniline. In this new, simple and economical method, which is environmentally safe and requires less time, oxo‐centered carboxylate species of ruthenium(III) in acetic acid medium and hydrated ruthenium(III) chloride in aqueous medium probably catalyze the oxidation. Copyright © 2005 John Wiley & Sons, Ltd.     

Reductive nitrosylation of tetraoxometallates—XVII. Molybdate-hydroxylamine-cyanide reaction, and synthesis and characterization of K2[Mo(NO)(CN)5] and (NMe4)2[Mo(NO)(CN)4]

A reaction condition is established which determines the nature of the products in the molybdate-hydroxylamine-cyanide reaction. With hydroxylamine always used in excess, it is the hydroxyl ion concentration of the reaction mixture which plays a vital role in determining whether K₄[Mo(NO)(CN)₅] or K₂[Mo(NO)(CN)₅] is obtained exclusively. The latter product is hereby reported for the first time. Its powder diffractogram being typical of a cubic system, a gross structural characterization has been made possible. The former under aqueous, aerobic conditions yields a new product, (NMe₄)₂[Mo(NO)(CN)₄].