Metal complexes of some asymmetric diaminodiamide ligands—III1,2: Rates of conversion from octahedral to square planar complexes of Ni(II)

Dissociation of the two amide protons from complexes of asymmetric diaminodiamides with Ni(II) in aqueous solution occurs under moderately basic conditions. The loss of the protons is accompanied by a conversion of the complex from octahedral to square planar. The rates of conversion for complexes NiL²⁺ were measured spectrophotometrically and were found to depend linearly on [OH^?]. The diaminodiamide ligands used were S, R, S- and S, S, S-N, N′-dialanylpropylenediamine (DAPN), S, S-N, N′-dialanylethylenediamine (DAEN), R-N, N′-diglycylpropylenediamine (DGPN), and N, N′-diglycylethylenediamine (DGEN). The rates varied in the order SS-DAEN > DGEN > SRS-DAPN > R-DGPN ≈ SSS-DAPN.     

Reparameterization of the scalar potential in the two Higgs doublet model

In the two Higgs doublet model with no additional symmetries in the scalar sector (different from the gauge and Lorentz symmetries), it is customary to reparameterize the model by rotating the scalar doublets so that one of the vacuum expectation values vanishes. It is well known that the Yukawa sector of the model is unaffected by such a transformation. Notwithstanding this, since the Higgs potential must also be transformed, it is necessary to show that such a sector is also unaltered in its physical content. We demonstrate that the physical content of the potential is invariant even when the charge conjugation symmetry is demanded. PACS 12.60.Fr; 11.30.Er; 11.15.Ex; 11.30.Hv     

Electric relaxation in chemically synthesized polyaniline: study using electric modulus formalism

A method of dielectric spectroscopy was used to determine the electric properties of chemically synthesized polyaniline (PANI) with special emphasis on the influence of acid and water doping levels on the polymer properties. The dependence of the dielectric loss factor (tan δ) on the temperature (in the range from − 100 to + 100°C) and the frequencies of the ac voltage (F = 0.1–30 000 Hz; amplitude of the voltage 1 V) were measured. They were subsequently transformed into the temperature and frequency dependences of a complex electric modulus, M*. Tan δ(F, T) and M(F, T)) presentations were both used in the analysis of the electric properties of PANI samples to compare their informative possibilities. At least two modes of the polymer response to varying temperature and frequency were resolved. Each mode corresponds to a certain area in an electric map of the system (log F versus 1/T plane) with their positions displaced towards higher frequencies and lower temperature with increases of both acid and water concentration in PANI. This effect is interpreted in terms of a unified mechanism of interaction of water and acid molecules with polymer backbone.     

Synthesis of 1H- and 2H-pyrazolo[3,4-c][2,1]benzothiazepines

Starting from ethyl chlorosulfonylpyrazole-4-carboxylates we have carried out the synthesis of ketones 3 and 4 which are the first two structures of the novel 1H- and 2H-pyrazolo[3,4-c][2,1]benzothiazepine ring systems.     

Analytical applications of 1,10-anthraquinones: A review

Analytical aspects of the chemistry in solution of 1,10-anthraquinone (AQ) derivatives is reviewed. The information about photometric and fluorimetric determination of inorganic species has been condensed and presented in tabular form.