Rate constants for the reaction of OH radicals with CH3CN, C2H5CN AND CH2=CH-CN in the temperature range 298–424 K

Rate constants for the reactions of OH with CH₃CN, CH₃CH₂CN and CH₂=CH-CN have been measured to be 5.86 × 10⁻¹³ exp(−1500 ± 250 cal mole⁻¹/RT), 2.69 × 10⁻¹³ exp(−1590 ± 350 cal mole⁻¹/RT and 4.04 × 10⁻¹² cm³ molecule⁻¹ s⁻¹, respectively in the temperature range 298–424 K. These results are discussed in terms of the atmospheric lifetimes of nitrfles.     

Sensitized multiphoton dissociation of UF6 IN SF6-UF6 mixtures by a tea CO2 laser

UF₆ undergoes decomposition in the presence of SF₆ when mixtures of both are irradiated with a TEA CO₂ laser. The mechanism for UF₆ decomposition may involve vibrational energy transfer from excited SF₆ and laser absorption from the same laser pulse by excited UF₆ in its vibrational quasi-continuum     

Studies in sesquiterpenes—LVIII : Deodardione,a sesquiterpene diosphenol and,limonenecarboxylic acid,a possible norsesquiterpene—compounds from the wood of cedrus deodara loud.

Isolation and structure elucidation of a C₁₁ mono-carboxylic acid, apparently a nor-sesquiterpene, and, a sesquiterpene diosphenol from the essential oil of Cedrus deodara Loud. are described.     

Tea CO2 laser-induced deuterium exchange in the ammonia—fluoroform-d system

Vibrational excitation of CDF₃ and NH₃ at 970 cm^?1 by a TEA CO₂ laser results in deuterium—hydrogen exchange suppressing the IR-laser-induced multiphoton chemistry of CDF₃.     

Some intense sources of radiation for the alkali and alkaline earth elements

Five new methods are described for the preparation of intense narrow line sources of resonance radiation for the alkali and the alkaline earth elements. Optimum conditions for their preparation and operation are described and their suitability for atomic fluorescence spectrometric purposes has been investigated. The most successful method involves a discharge in flowing atmospheric pressure argon in a quartz tube. A small quantity of the element (or element halide) of interest is suspended in a quartz cup in the discharge stream. The resulting source is applicable to a wide range of relatively involatile elements and, although it is somewhat short lived, it may be recharged readily. Microwave excitation of hollow cathode lamps was not found to be very useful for analytical purposes.     

Studies in sesquiterpenes—LIII : Deodarone and atlantolone,new sesquiterpenoids from the wood of Cedrus deodara loud

Isolation and structure determination of a novel bisabolane-based tetrahydro-γ-pyrone from the essential oil from the wood of Cedrus deodara Loud is described. The compound, which has been named deodarone, has been chemically correlated with the sesquiterpene ketone, atlantone. An hydroxy ketone, designated as atlantolone, has also been isolated. This compound appears to be the precursor of the new C₁₂-ketone, recently described as a component of the essential oil of Cedrus atlantica Manet.     

Studies in sesquiterpenes—LII: Isohimachalone: a constituent of the essential oil from wood of Cedrus deodara loud

Isolation and structure elucidation of a new bicyclic sesquiterpene of a new carbo-skeleton, from the essential oil from the wood of Credrus deodara loud., is reported. The structure rests on a direct correlation with β-himachalene.     

Organic reactions in a solid matrix—IV: Oxirane rearrangement on modified-alumina

Rearrangement of methyldialkyl-substituted oxiranes to the corresponding allylic secondary alcohols with active Al₂O₃ is accompanied by carbonium ion rearrangements. The effect of modifying the Al₂O₃ with various bases or salts has been studied. With NaOH-modified Al₂O₃, the carbonium ion-rearrangements are significantly suppressed, and rearrangement to the allylic alcohols becomes the major pathway. Rearrangement of 2,10-epoxypinane (both isomers) on Al₂O₃-NaOH is reported.     

Separation and quantitative determination of the cerium group lanthanides by gas-liquid chromatography

A gas chromatographic method is reported for the separation and subsequent quantitative determination of the cerium group lanthanides. The lanthanides (RE) are synergistically extracted from aqueous solution with the polyfluorinated beta-diketone 1,1,1,2,2,6,6,7,7,7-decafluoro-3,5-heptanedione, H(FHD), as ligand, and di-n-butylsulphoxide, DBSO, as neutral donor. The composition of the extracted species is reported to be RE(FHD)(3) .2DBSO. Thermogravimetric analysis of the complexes is reported. Analytical curves were prepared and found to be usable over the range of 0.1-10 mug of metal. Individual lanthanides were determined with 99.0 % recovery with a relative mean deviation of +/-2.0%. Mixture of lanthanides were analyzed with 101.2% recovery with a relative mean deviation of +/-2.2%.     

Studies in sesquiterpenes—LVI: Isolongifolene (part 7): mechanism of rearrangement of longifolene to isolongifolene—II

The question of possible neutral intermediates which may lie on the reaction pathway in going from longifolene to isolongifolene has been investigated using BF₃·Et₂O-AcOD and D₃PO₄-dioxane, as reagents. It has been found that longicyclene is not an obligatory intermediate. The mode of cleavage of cyclopropane ring in longicyclene has been investigated.     

Some observations concerning the direct titration of nitrite with cerium(IV)

Direct titration of nitrite with cerium (IV), with ferroin as indicator, is shown to give satisfactory results if the acidity is kept between 0.033 and 0.055M at the end-point. Loss of nitrous acid owing to volatilization and decomposition is discussed. From 10 to 60 mg of sodium nitrite can be estimated with a standard deviation of 5 mug and an average error of 0.2%.     

Cellular and foamed plastics as separation media A new geometrical form of the solid phase in analytical liquid-solid contact

There has been considerable interest during the last few years in using cellular (foamed) plastics (mainly polyurethanes) either unloaded or as a means of immobilizing hydrophobic organic reagents, powdered ion-exchangers or finely divided precipitates, for the collection and separation of inorganic or organic species from aqueous solution. Foamed plastics with anchored (bonded) functional groups have also been used for the same purpose. It has been realized that the application of cellular plastics is often advantageous not only for quantitative work but also for qualitative and semiquantitative analysis. Methods available on the application of cellular and foamed plastics for the collection, separation and recovery of various inorganic and organic components from aqueous solution are reviewed.     

Properties of the X 1Σ state of BF

A perturbation theoretical approach for treating electron correlation has been used to calculate the potential energy curve and dipole moment function of BF near its equilibrium bond length. A dipole moment of 0.89 D (B^?F⁺) is predicted at R_e. When the bond is stretched by ≈0.2 Å the dipole reverses sign.     

Infrared spectra and molecular structure: Part II. N-methyl- and N,N-dimethylaminobenzoic acids

Infrared spectra of N-methyl- and N,N-dimethylaminobenzoic acids have been investigated. All the acids except N,N-dimethylanthranilic acid showed neutral structures in the solid state. The N,N-dimethylanthranilic acid, however, exhibited a dipolar structure with strong intramolecular hydrogen bonding in the solid state while in solution it is neutral.     

Controlled potential iodometric determination of iron after extraction with di-isopropyl ether

A selective method for the determination of small amounts of iron in different kinds of samples with complex matrices has been developed. The iron in a sample is converted into the ferric state and after extraction with di-isopropyl ether the ferric iron is iodometrically determined with a controlled-potential apparatus previously described. Iron concentrations lower than 1 ppm can be determined.     

Quenching of aromatic hydrocarbon triplet states by stable carbon free radicals

Quenching of the triplet states of a series of polynuclear aromatic hydrocarbons in solution by three members of the bis-biphenylene allyl radical family has been studied. Bimolecular rate constants for the quenching process have values corresponding to a diffusion controlled process; in contrast to quenching by nitroxide radicals, there is no clear dependence of quenching rate constant on the triplet energy of the hydrocarbon being quenched. It is proposed that the mechanism leading to quenching is based on an exchange interaction between the tree radical and the triplet state.