Publications (58) View all
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Article: Spectroscopic and structural investigation of the confinement of D and L dimethyl tartrate in lecithin reverse micelles.
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ABSTRACT: The confinement of D and L dimethyl tartrate in lecithin reverse micelles dispersed in cyclohexane has been investigated by FT-IR, polarimetry, electronic and vibrational circular dichroism (ECD and VCD), 1H NMR, and small-angle X-ray scattering (SAXS). Measurements have been performed at room temperature as a function of the solubilizate-to-surfactant molar ratio (R) at fixed lecithin concentration. The analysis of experimental data indicates that the dimethyl tartrate molecules are solubilized within reverse micelles in proximity to the surfactant head groups in the same way for the D and L forms. The encapsulation of dimethyl tatrate within lecithin reverse micelles involves changes in its H-bonds, from what is observed in the pure solid or in CCl4 solutions; this is a consequence of the establishment of specific solute-surfactant headgroup interactions and of confinement effects. In the 0 < or = R < or = 1.7 range, SAXS profiles of dimethyl tartrate/lecithin/ cyclohexane micellar solutions are well-described by a model of interacting polydisperse spherical micellar cores whose mean radius does not change appreciably with R (i.e., it changes from about 18 to 20 angstroms). 1H NMR diffusion measurements of both dimethyl tartrates and lecithin were rationalized in terms of collective translational motions of the entire micellar aggregate and of their molecular diffusion among clusters of reverse micelles. The association of optically active lecithin with D and L dimethyl tartrate leads to the formation of self-organized supramolecular aggregates whose interesting chiroptical features are evidenced by polarimetry and CD.The Journal of Physical Chemistry B 04/2009; 113(10):3024-33. · 3.70 Impact Factor -
Article: Monoaza[5]helicenes. Part 2: Synthesis and Characterization and theoretical calculations
Tetrahedron 01/2006; 62(1):139-148. · 3.03 Impact Factor -
Article: Mediated Radical Addition of Ethers to Aldimines Generated in Situ under aqueos conditions
Tetrahedron Letters 11/2005; 46(48):8351-8354. · 2.68 Impact Factor -
Article: Synthesis and Characterization of Some Aza[5]helicenes
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ABSTRACT: A systematic study on the synthesis and properties of aza[5]helicenes bearing one or two nitrogen atoms in selected ring positions is reported for the first time. This photochemical approach can be conveniently applied to the preparation of either mono- or diaza[5]helicenes. The aza[5]helicenes were characterized by NMR spectroscopy, X-ray crystallography, emission spectroscopy, and luminescence lifetime. The extremely long triplet lifetime observed (in the range of seconds) makes these molecules promising candidates for practical applications in photo- and optoelectronics.Annalen der Chemie und Pharmacie 04/2005; 2005(7):1247 - 1257. · 3.10 Impact Factor -
Article: Synthesis and Characterization of Some Aza[5]helicenes
European Journal of Organic Chemistry 03/2005; · 3.33 Impact Factor
