Axions from chiral family symmetry

We investigate the possibility that family symmetry, G_F, is spontaneously broken chiral global symmetry. We classify the interesting cases when family symmetry can result in an automatic Peccei-Quinn symmetry U(1)_PQ and thus provide a solution to the strong CP problem. The result disfavors having two or four families. For more than four families, U(1)_PQ is in general automatic. In the case of three families, a unique Higgs sector allows U(1)_PQ in the simplest case of G_F = [SU(3)]³. Cosmological consideration also puts strong constraint on the number of families. For G_F = [SU(N)]³ cosmology singles out the three-family (N = 3) case as a unique solution if there are three light neutrinos. Possible implication of decoupling theorem as applied to family symmetry breaking is also discussed.     

Spectrophotometric study of the interaction of some hydroxyanthraquinones (HAQs) with magnesium(II) in a cationic micelle

Six different hydroxyanthraquinones (HAQs) in aqueous micellar (cationic, anionic and non-ionic) media were tested as effective and selective chelators for the MgII ion in alkaline conditions. Of these 1,4 and 1,8-dihydroxyanthraquinones were found to effectively bind to MgII ions and were useful for the ppm level spectral determination of MgII ion. The MgII ion forms 1 : 1 and 1 : 2 chelates with 1,4-and 1,8-dihydroxyanthraquinones, respectively, which have maximum absorption at 610 and 575 nm, respectively. MgII can be determined in the presence of a large excess of foreign ions including the CaII ion. The statistical analysis of the results, apparent pK(a), expected bathchromic shift of the reagent absorption, molar absorptivity change and electronic spectra in various organized media are discussed.     

A Bis(azo-imine)palladium(II) System with 10 Ligand pi Electrons. Synthesis, Structure, Serial Redox, and Relationship to Bis(azooximates) and Other Species

The first azo-imine chelate system, Pd(N(H)C(R)NNPh)(2) (Pd(RA)(2)), has been isolated in the form of diamagnetic solids by the 6e(-)-6H(+) reduction of bis(phenylazooximato)palladium(II), Pd(N(O)C(R)NNPh)(2) (abbreviated Pd(RB)(2)), with ascorbic acid in a mixed solvent (R = Ph, alpha-naphthyl). Selected spectral features are described. The X-ray structures of Pd(PhA)(2) and Pd(PhB)(2) have revealed trans-planar geometry consistent with metal oxidation state of +2. Bond length trends within the chelate rings are rationalized in terms of steric and electronic factors. In Pd(PhA)(2) a total of 10 ligand pi electrons are present, each formally monoanionic ligand contributing five. Model EHMO studies have revealed that the filled HOMO (a(u)) in Pd(RA)(2) is a bonding combination of two ligand pi orbitals with large azo contributions. The LUMO (b(g)) is roughly the corresponding antibonding combination. The outer pi-electron configuration of Pd(RA)(2) is (a(u))(2)(b(g))(0). Four successive voltammetric responses, two oxidative and two reductive, are observed. The E(1/2) range is -1.3 to +0.8 V vs SCE for Pd(PhA)(2) in a 1:9 MeCN-CH(2)Cl(2) mixture (Pt electrode). EPR and electronic spectra of the electrogenerated one-electron-oxidized complex Pd(PhA)(2)(+) are described. The azo-imine system is compared with imine-imine and azo-azo systems. Crystal data for the complexes are as follows. Pd(PhA)(2): crystal system monoclinic; space group C2/c; a = 18.167(5) ?, b = 7.420(3) ?, c = 16.527(6) ?; beta = 92.70(3) degrees; V = 2225(1) ?(3); Z = 4; R = 2.61%, R(w) = 3.58%. Pd(PhB)(2): crystal system monoclinic; space group P2(1)/n; a = 5.735(5) ?, b = 10.797(6) ?, c = 18.022(11) ?; beta = 97.73(6) ?; V = 1105(1) ?(3); Z = 2; R = 3.37%; R(w) = 3.40%.     

Synthesis of monohydroxy-functionalized triphenylene discotics: green chemistry approach

This paper presents an environmentally benign procedure for the preparation of monohydroxy-functionalized triphenylenes using simple ionic reagents. Pyridinium hydrochloride, pyridinium hydrobromide, N-methyl pyridinium iodide, N-ethyl pyridinium bromide, and 1-n-butyl-3-methyl imidazolium bromide have been employed to prepare various monohydroxypentaalkoxytriphenylenes, which are valuable precursors for the synthesis of a variety of discotic monomers, dimers, oligomers, and polymers.     

Solvent effect on the rate of decomposition of peroxy compounds

Solvent effect on the rate of decomposition of peroxy compounds was described by multiparameter equations based on the linear Gibbs energy relationship. In the decomposition of dialkyl peroxides, the determining factors are the cohesion energy density of solvents and their ability to electrophilic solvation, which accelerate the process. In the case of hydroperoxides, the nonspecific solvation factor should additionally be taken into account.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1459–1463.Original Russian Text Copyright © 2004 by Midyana, Makitra, Palchikova.     

Improved separation of metallothionein isoforms by the presence of cyclodextrin in capillary zone electrophoresis

Capillary zone electrophoresis (CZE) with cyclodextrin (CD) in the polyacrylamide-coated capillary was used to study metallothionein (MT) forms in the horse kidney preparation produced commercially by Sigma. It is known that CDs form complexes with hydrophobic amino acids. The results show that the presence of CD improves the separability of the various MT forms, including the MT-IA and the MT-IB forms, metallothionein aggregates, as well as the so far unidentified a and b forms. This was true both below and above the isoelectric points (pIs), although the migration times were somewhat longer at increasing CD concentrations for runs at constant voltage than with constant current.     

Solubility and distribution of radon in organic solvents

The influence of physicochemical properties of solvents on the solubility of radon in them can be described by multiparameter linear equations taking into account various solvent characteristics; the decisive (and negative) effect on the radon solubility is exerted by the cohesion energy density and polarity of the solvent. This approach is efficient for summarizing data on the distribution ratios of radon between organic and aqueous phases.