Trypanocidal activity of oxoaporphine and pyrimidine-β-carboline alkaloids from the branches of Annona foetida Mart. (Annonaceae)

Phytochemical investigation of the branches of Annona foetida Mart. led to isolation from the CH(2)Cl(2) extract of four alkaloids: Atherospermidine (1), described for the first time in this species, liriodenine (2), O-methylmoschatoline (3), and annomontine (4). Their chemical structures were established on the basis of spectroscopic data from IR, MS, NMR (1D and 2D), and comparison with the literature. Compounds 2-4 showed potent trypanocidal effect when evaluated against epimastigote and trypomastigote forms of Trypanosoma cruzi.     

Effect of the aliphatic chain length on electrical double layer formation at the liquid/vacuum interface in the [C(n)mim][BF4] ionic liquid series

Neutral impact collision ion scattering spectroscopy (NICISS) was used to determine the surface structure of three ionic liquids, 1-hexyl-3-methylimidazolium [C(6)mim], 1-octyl-3-methylimidazolium [C(8)mim], 1-decyl-3-methylimidazolium [C(10)mim] tetrafluoroborates [BF(4)]. Concentration depth profiles of the elements in an ionic liquid (IL) homologous series with a common anion were obtained. We show that separation between the oppositely charged ions is seen for all three ionic liquids, resulting in an electrical double layer formation. The surface charge shifts from more positive to more negative with increasing aliphatic chain length.     

Non-oxo vanadium(IV) alkoxide chemistry: solid state structures, aggregation equilibria and thermochromic behaviour in solution

The reversible thermochromic behaviour of homoleptic [{V(OR)(4)}(n)] complexes in solution [R = Pr(i) (product I), Bu(s) (B(s)), Nep (N) and Cy (C)] is accounted for the existence of an aggregation equilibrium involving dimeric and monomeric species in which vanadium(iv) is respectively five- and four-coordinate. Bulky R groups such as Bu(t) and Pe(t) (tert-pentoxide) prevent aggregation and therefore give rise to exclusively mononuclear compounds (B(t) and P(t), respectively) that are not thermochromic. The complexes and their temperature-dependent interconversion were characterised by single crystal X-ray diffractometry, magnetic susceptibility measurements and electronic, FTIR and EPR spectroscopies in a wide temperature range. Equilibrium constants and enthalpy and entropy changes for the dimerization reactions have been determined and compared with literature data.     

γ-ray spectroscopy of excited states in 61 30Zn31

The ⁶¹ ₃₀Zn₃₁ isotope has been produced at the Oak Ridge National Laboratory in the fusion-evaporation reaction ⁴⁰Ca(²⁴Mg, 2pn)⁶¹Zn at 104MeV. The experimental set-up allowed γ-rays to be detected in the CLARION Ge detector array in coincidence with the detection of recoiling nuclei in the focal plane at the end of the recoil mass spectrometer. This provides a unique identification of γ-rays belonging to ⁶¹Zn. The excited states have been explored by means of recoil- γγ coincidences, and the resulting decay scheme comprises almost 70 transitions. The data reveal numerous non-yrast states and suggest a revised spin and parity assignment for a previously observed superdeformed band. The resulting decay scheme is compared to predictions from different sets of large-scale shell model calculations.     

A quark parton model for hadronic fragmentation distributions

The one-particle inclusive distributions in the fragmentation regions in hadronic interactions are described in a parameter free way by a simple additative quark parton model by means of the quark fragmentation functions measured in leptoproduction. We interpret the result so that while the main interaction in hadronic collisions is due to the wee partons almost all the momenta is carried by one of the valence quarks yielding fragmentation region distributions similar to the ones in leptoproduction.     

Photochemistry of the anthracene chromophore: Triplet-sensitized isomerizations of dianthrylethanes

The photochemical isomerization of 1,2-di(9-anthryl)ethane can be sensitized by biacetyl to proceed by intramolecular Diels-Alder reaction. The molecular geometry of dianthrylethanes affects their triplet state reactivity.     

Exact solution of the particle-rotor model,angular momentum spread and transition rates

The particle-plus-rotor model with valence particles in an $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ shell is solved exactly including single-particle splitting and pairing forces. Backbending and the spread of angular momentum of the valence shell is studied in detail for the two lowest bands and quadrupole transition rates are calculated.