Quantum field theories of vortices and anyons

We develop the quantization of topological solitons (vortices) in three-dimensional quantum field theory, in terms of the Euclidean region functional integral. We analyze in some detail the vortices of the abelian Higgs model. If a Chern-Simons term is added to the action, the vortices turn out to be anyons, i.e. particles with arbitrary real spin and intermediate () statistics. Localization properties of the interpolating field, scattering theory and spin-statistics connection of anyons are discussed. Such analysis might be relevant in connection with the fractional quantum Hall effect and two-dimensional models of HighT _csuperconductors.     

Homolytic substitutions in indolinone nitroxide radicals—I: Reaction with aroyloxyl radicals

Indolinone nitroxides undergo a homolytic substitution with aroyl oxyl radicals, leading to two isomers, 7-aroyloxy- and 5-aroyloxy-derivative, respectively, whose structures were assigned on the basis of the ESR hfccs and of the ¹H NMR spectra of the corresponding amines. The presence of aroyl oxyl radicals in the reaction medium was demonstrated by thermal decomposition of benzoyl peroxide in the presence of aromatic acids.     

Fullerohelicates: a new class of fullerene-containing supermolecules

A multicomponent array made of a bis-copper(I) helicate core and two peripheral fullerene subunits has been prepared and electron transfer from the photoexcited Cu(I)-complexed unit to C60 occurs.     

Structure‐Dependent Photoinduced Electron Transfer in Fullerodendrimers with Light‐Harvesting Oligophenylenevinylene Terminals

Oligophenylenevinylene (OPV)‐terminated phenylenevinylene dendrons G1 – G4 with one, two, four, and eight “side‐arms”, respectively, were prepared and attached to C₆₀ by a 1,3‐dipolar cycloaddition of azomethine ylides generated in situ from dendritic aldehydes and N‐methylglycine. The relative electronic absorption of the OPV moiety increases progressively along the fullerodendrimer family C₆₀G1 – C₆₀G4 , reaching a 99:1 ratio for C₆₀G4 (antenna effect). UV/Vis and near‐IR luminescence and transient absorption spectroscopy was used to elucidate photoinduced energy and electron transfer in C₆₀G1 – C₆₀G4 as a function of OPV moiety size and solvent polarity (toluene, dichloromethane, benzonitrile), taking into account the fact that the free‐energy change for electron transfer is the same along the series owing to the invariability of the donor–acceptor couple. Regardless of solvent, all the fullerodendrimers exhibit ultrafast OPV→C₆₀ singlet energy transfer. In CH₂Cl₂, the OPV→C₆₀ electron transfer from the lowest fullerene singlet level (¹C₆₀*) is slightly exergonic (ΔG_CS≈0.07 eV), but is observed, to an increasing extent, only in the largest systems C₆₀G2 – C₆₀G4 with lower activation barriers for electron transfer. This effect has been related to a decrease of the reorganization energy upon enlargement of the molecular architecture. Structural factors are also at the origin of an unprecedented OPV→C₆₀ electron transfer observed for C₆₀G3 and C₆₀G4 in apolar toluene, whereas in benzonitrile, electron transfer occurs in all cases. Monitoring of the lowest fullerene triplet state by sensitized singlet oxygen luminescence and transient absorption spectroscopy shows that this level is populated through intersystem crossing and is not involved in photoinduced electron transfer.     

One-dimensional order in atactic polyacrylates containing aromatic side groups

To help in the understanding of the relations between chemical structure and morphological order in polymers of the type of poly(p-biphenyl acrylate) (PPBA), some polymers of similar structure have been synthesized and some of their physical properties studied. These polymers are: poly(p-biphenyl methacrylate), poly(vinyl p-phenyl benzoate), poly(p-phenyl benzyl acrylate), poly(p-benzyl phenyl acrylate) and poly(p-cyclohexyl phenyl acrylate) (PPCPA). Only PPCPA has been shown to possess a one-dimensional order in the solid state for reasons which are briefly discussed.The effect of copolymerization on the structural order of PPBA has also been given preliminary study. Copolymers of p-biphenyl acrylate (PBA) with p-biphenyl methacrylate (PBMA), N-vinyl carbazole (NVC) and p-cyclohexyl phenyl acrylate (PCPA) have been prepared and their properties have been studied by DSC and X-ray techniques. Small concentrations of PBMA or NVC units are sufficient to cancel the order of PPBA. On the contrary, copolymers of PBA and PCPA of any composition display morphological order in the solid state.     

Dirac's aether in relativistic quantum mechanics

The introduction by Dirac of a new aether model based on a stochastic covariant distribution of subquantum motions (corresponding to a vacuum state alive with fluctuations and randomness) is discussed with respect to the present experimental and theoretical discussion of nonlocality in EPR situations. It is shown (1) that one can deduce the de Broglie waves as real collective Markov processes on the top of Dirac's aether; (2) that the quantum potential associated with this aether's modification, by the presence of EPR photon pairs, yields a relativistic causal action at a distance which interprets the superluminal correlations recently established by Aspect et al.; (3) that the existence of the Einstein-de Broglie photon model (deduced from Dirac's aether) implies experimental predictions which conflict with the Copenhagen interpretation in certain specific testable interference experiments.     

Stable nitroxide radicals from phenylisatogen and arylimino-derivatives with organo-metallic compounds

Stable nitroxide radicals were obtained by the oxidation of 1-hydroxyindolines prepared by allowing the organo-metallic compounds to act upon 2-phenylisatogen and arylimino-derivatives. In both cases nitroxides are obtained with a ^N of approximately 9 gauss, in agreement with similar known compounds. The ESR spectra of numerous nitroxide radicals are discussed and a number of cases of magnetic non-equivalence of methylenic protons adjacent to asymmetric carbon are brought to light.     

Separation of capsular polysaccharide K4 and defructosylated K4 by high-performance capillary electrophoresis

A rapid, highly sensitive and reproducible high-performance capillary electrophoresis (HPCE) method (electrokinetic chromatography with sodium dodecyl sulfate) is described for the determination of the polysaccharide from the uropathogenic Escherichia coli K4 bacteria (05:K4:H4) and its defructosylated product. The two polyanions, K4 and defructosylated K4, are separated and readily determined within 30 min on an uncoated fused-silica capillary using normal polarity at 20 kV and detection at 200 nm. A linear relationship was found for the two polysaccharides over a wide range of concentrations, from approximately 30 ng (0.5 microg/microL) to 210 ng (3.5 microg/microL). The described method was used to evaluate the defructosylation process of K4 under drastic acid conditions.