Structure determination and absolute configuration of cannabichromanone derivatives from high potency Cannabis sativa

Three new cannabichromanone derivatives were isolated from high potency cannabis, along with the known cannabichromanone. Full spectroscopic data, including the use of electronic circular dichroism and Mosher ester analysis to determine the absolute configuration of these compounds, are reported. All isolates were tested for antimicrobial, antimalarial, antileishmanial, and anti-oxidant activities.     

Spin squeezing and quantum correlations

We discuss the notion of spin squeezing considering two mutually exclusive classes of spin-s states, namely, oriented and non-oriented states. Our analysis shows that the oriented states are not squeezed while non-oriented states exhibit squeezing. We also present a new scheme for construction of spin-s states using 2s spinors oriented along different axes. Taking the case of s=1, we show that the ‘non-oriented’ nature and hence squeezing arise from the intrinsic quantum correlations that exist among the spinors in the coupled state.     

A convenient synthesis of amino-substituted 1,3,5-oxadiazinium salts

Diacyl chlorides react with dialkylcyanamide in the presence of a Lewis acid to give amino-substituted bis-1,3,5-oxadiazinium salts in excellent yields. A mechanism leads to the formation of the product has been postulated. All new compounds have been characterized by ¹H-nmr, ¹³C-nmr, ir-spectroscopy and elemental analysis.     

Energy levels for the Coulomb potential with cut-off

Zusammenfassung Die Absorptionsbanden der Alkalihalogenidkristalle werden auf Elektronen zurückgeführt, die an leeren Gitterstellen eingefangen sind. Als Feld wird ein bei kleinen Distanzen horizontal abgeschnittenes Coulomb-Feld angesetzt. Die Eigenwerte werden im ganzen Energiebereich aus einer genauen Reihenentwicklung der Lösungen der Schrödinger-Gleichung bestimmt.     

Substituent and solvent effects on the rate of the reaction of 2-methyl-4-phenyl-thiazole ethiodide with substituted benzaldehydes

Condensation of 2-methyl-4-phenyl-thiazole ethiodide (1) with aromatic aldehydes in presence of piperidine as base catalyst has been studied kinetically at different temperatures. The rate in presence of low concentration of piperidine (<0.5M) is found to be represented by the third order equationv=k [1] [aldehyde] [piperidine]. On the other hand the rate in presence of 1.013M piperidine is represented by the second-order equation:v=k [1] [aldehyde]. It is concluded from the kinetic results that the dehydration step of the intermediate aldol compound is the rate determining step of the reaction. The dependence of the mechanism of the reaction and the thermodynamic parameters of activation on the molecular structure of the various aromatic aldehydes used is discussed. In various organic solvents, the rate of the reaction increases as the dielectric constant of the medium is increased. The energy of activation and the thermodynamic parameters of activation were calculated and discussed in terms of solvent properties.

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Substituenten- und Lösungsmittel-Effekte auf die Geschwindigkeit der Reaktion zwischen 2-Methyl-4-phenylthiazol-ethiodid und substituierten Benzaldehyden

Zusammenfassung Die Kinetik dieser Kondensation wurde bei verschiedenen Piperidinkonzentrationen (basischer Katalysator), unter Variation der Temperatur und in Abhängigkeit von der Polarität des Lösungsmittels für verschiedene substituierte Benzaldehyde untersucht. Bei niedriger Piperidinkonzentration gehorcht die Reaktion einer Gleichung dritter Ordnung:v=k [Thiazo] [Ald.] [Pip.]; bei großer Konzentration (1.013M) gilt eine Gleichung zweiter Ordnung:v=k [Thizol] [Ald.]. Es wird ein Mechanismus vorgeschlagen, wobei der geschwindigkeitsbestimmende Schritt die Dehydratisierung des intermediär gebildeten Aldols ist. Aktivierungsenergien und andere thermodynamische Parameter wurden bestimmt und im Hinblick auf die Lösungsmittelpolarität diskutiert.

     

Field distribution in a fabry-perot interferometer with inclined mirrors

The field is localized in planes perpendicular to the principal section of the wedge formed by the mirrors; the positions of these are defined by Airy's function, with secondary components accessible to observation.I am indebted to Professor F. A. Korolev for discussions.     

Effects of polymer–fiber interactions on rheology and flow behavior of suspensions of semi-flexible fibers in polymeric liquids

Rheological properties of suspensions of fibers in polymeric fluids are influenced by fiber–polymer interactions. In this paper, we investigate this influence from both experimental and modeling standpoints. In the experimental part of this investigation, we have changed the fiber–polymer interactions by treating the surface of the fibers. The resulting effects are observed using scanning electron microscopy and dynamic mechanical analysis techniques and quantified from the measurements of the viscosity in the start-up of shear flows and dynamic tests in the linear viscoelastic range region. The results are interpreted with the help of a mesoscopic rheological model developed for suspensions of fibers in viscoelastic fluids.