Rearrangement of N-Allyl-α,α-dichloroamides, β- or γ- Functionalized,to Substituted Analogues of the γ-Aminobutyric Acid (GABA)

The rearrangement of γ-chlm, β-hydroxy or β-vmyl N-allyl-N-benzyl-α,α-dichlorocarboxyamides to γ-aminobutynic acid analogues is efficiently promoted by CuCI\N,N,N′,N′-tetramethylethylendiamine. With the β-vinyl functionalization a tandem radical-radical reaction, yieldmg 3-aza-2-oxo-bicyclo[3,3,0]actatre adducts, is also observed.     

The CuBr/Fe0 Promoted Radical Addition of Methyl 2-Br-2-Cl-Carboxylates to OLEFINS

Methyl 2-Br-2-Cl-carboxylates afford 2-alkyl-2-Cl-4-Br-carboxylates in fair yields by reaction with terminal alkenes, under mild conditions, through a radical process promoted by CuBr/Fe⁰ in DMF/CH₂C1₂.     

Electric and magnetic properties of PMMA/manganite composites

We present the synthesis and characterization of the La_2/3Sr_1/3MnO₃ manganite in the form of tapes using polymethyl methacrylate (PMMA) as binder. We have studied their electric and magnetic properties as a function of temperature and magnetic field. The magnetization results have been shown to be dominated by the intrinsic magnetic properties of the manganite. Resistivity measurements showed an insulating behavior in the whole range of temperatures measured, indicating that the percolation threshold of manganite grains has not been reached even for the sample with 35% of PMMA relative content. The obtained magnetoresistance is largest in the sample with 35% of PMMA relative content.     

Orthogonality and Additivity Modulo Z

Let E be a real inner product space of dimension at least 2. Suppose ? : E → ? satisfies If there exist a neighbourhood U of the origin and γ ∈ (0, 1/4) such that ?(U) ? (?γ,γ) + ?, then there exist a real constant c and a continuous linear functional g : E → ? such that Suppose Φ : E → ? satisfies If there exist a neighbourhood U of the origin and β ∈ (0, +∞) such that ¦Φ(x)¦ ≤ β?(Φ(x)) for every x ∈ U, then either Φ vanishes on E? {0} or there exist additive functions a : ? → ? and A : E → ?, a real constant c and a continuous linear functional g : E → ? such that      

v-Triazolines. Part XIX. Thiocino[4,5-d]-1,2,3-triazole and thiocino[4,5-d]isoxazole derivatives

5-Amino-2,3,6,7-tetrahydrothiocines were reacted with arylazides yielding 1-aryl-9a-amino-1,3a,4,5,7,8,9,9a-octahydrothiocino[4,5-d]-1,2,3-triazoles which could be deaminated to 1-aryl-1,4,5,7,8,9-hexahydrothiocino-[4,5-d]-1,2,3-triazoles. Similarly, the above enamines yielded, with nitrile oxides, 3-aryl-9a-amino-3a,4,5,8,9,9a-hexahydrothiocino[4,5-d]isoxazoles which were transformed with acids into 3-aril-4,5,8,9-tetrahydrothiocino-[4,5-d]isoxazoles.     

Molecular structure and harmonic force field of AsCl3 by microwave spectroscopy

The microwave spectrum of four isotopically substituted species of AsCl₃ in the frequency range 100–220 GHz has been investigated. Four r_s structures were determined resulting in the following average values of the bond length and bond angle:The harmonic force field of AsCl₃ has been calculated and compared with that obtained without the aid of the centrifugal distortion constants.     

Microwave spectrum and molecular force field of tetratomic C2v molecules: NO2Cl

The rotational constants and quartic centrifugal distortion constants for NO₂³⁵Cl and NO₂³⁷Cl have been determined from an analysis of rotational transitions in the microwave and millimeter wave regions between 8.2–40 and 90–120 GHz, respectively.The values of the in-plane force constants in the general harmonic potential field have been obtained by combination of infrared and microwave data. Vibrational frequencies of ¹⁴NO₂Cl and ¹⁵NO₂Cl, inertia defects of NO₂³⁵Cl in the excited vibrational states v₃ = 1 and v₅ = 1, and first-order centrifugal distortion constants of NO₂³⁷Cl are the experimental data used in the least-squares fitting determination of force constants.     

Mechanical enhancement of cellulose nanofibril (CNF) films through the addition of water-soluble polymers

Cellulose - In this work, water-soluble polymers were screened through solution casting and polyvinyl alcohol (PVA) and poly(2-ethyl-2-oxazoline) (PEOX) were found as reinforcement agents for...