A mechanism for pulsar radiation

The methods available for the determination of the stability constants of non-extractable complexes by solvent extraction are reviewed. The method proposed by Connick and McVey is valid only when no complexes of the auxiliary-ligand exist in the aqueous phase. This is applicable only at very low concentrations of the auxiliary-ligand. Hence, the stability constants calculated by this method decrease with increasing concentration and approach the theoretical values only at low concentrations of the auxiliary-ligand. It is essential, therefore, to apply the rigorous method incorporating the constants for the metal-auxiliary-ligand to calculate the stability constants which are independent of the changes in the experimental conditions. This is illustrated by few typical calculations.     

Absorption spectrum of VO2+ ion doped in caesium cadmium sulphate hexahydrate single crystal

Results of the optical absorption spectrum of VO²⁺ ion doped in caesium cadmium sulphate hexahydrate studied at room (300 K) and liquid nitrogen (77 K) temperatures are reported. The site symmetry of the ion is found to be C_4ν. Correlating the optical and ESR spectral data, the molecular orbital coefficients are evaluated.     

Oxovanadium(IV) complexes of cyclohexanone semicarbazone and cyclohexanone thiosemicarbazone

Summary Oxovanadium(IV) complexes, VOL₂X₂ (X = Cl, Br and 0.5 SO₄), have been synthesised and characterised by elemental analysis, room temperature magnetic moment, electronic, i.r. and electron spin resonance studies. The complexes are hexacoordinate and have a distorted octahedral structure.     

E.p.r. spectra of mixed valence copper(II)-copper(I) systems

Summary Mixed valence (thiosemicarbazone)₂Cu^II-Cu^I complexes were prepared and their e.p.r. spectra in the polycrystalline state studied. Complexes derived from acetophenone- and propiophenonethiosemicarbazones exhibit strong copper(II)-copper(II) and copper(II)-copper(I) interactions, whereas those derived from benzyl methyl ketone and cyclohexanone show strong copper(II)-copper(I) interaction but almost no copper(II)-copper(II) interaction.     

The mass spectrum of 2,4-dihydroxybenzophenone oxime

2,4-Dihydroxybenzophenone Oxime is found to undergo loss of OH·, H₂O, NHOH·; and PhCNO when subjected to electron impact, revealing novel hydrogen and skeletal migrations. The fragmentation mechanisms are found to differ considerably from those of benzophenone oxime and we confirmed these cleavages by exact mass measurements and deuterium labelling.     

Direction of enolization of 1:3-diketones by mass spectrometry

A novel method of establishing the direction of enolization of a 1:3-diketone is to examine of the mass spectrum of the isoxazole obtained from it by hydroxylamine treatment. Thus, the products obtained from five 1:3 diketones,viz. l-(2-naphthyl)-3-phenylpropane-l :3-dione and its 3-p-toluyl,p-methoxyphenyl,p-nitrophenyl andp-chlorophenyl analogues, consist of both the possible isomeric 3:5-disubstituted isoxazoles in each case, indicating that each diketone exists in both the enolic forms. The percentage of the enols was derived, in a qualitative manner, from the ratio between the percentage abundances of the aroyl and naphthoyl cation peaks present in the mass spectrum of the product from each diketone. In four out of the five cases, each possible isomeric isoxazole was synthesised by the unambiguous chalconedibromide method and examination of the mass spectrum in each case revealed that either the aroyl or the naphthoyl cation peak was exhibited depending on whether the 5-substituent was an aryl or a naphthyl group respectively. A re-examination of the direction of enolization of 4-methoxydibenzoylmethane revealed that it existed in both the enolic forms, contrary to earlier observations.