Synthetic applications of aliphatic unsaturated alpha-H-alpha-amino acids

This article provides an overview of the literature concerning synthetic applications of unsaturated aliphatic amino acids in the period May 2000 to December 2004.     

Cylindrical solitons in shallow water of variable depth

Summary The propagation and the interaction of cylindrical solitons in shallow vater of variable depth are studied. Starting from the cylindrically symmetric version of the equations describing long waves in a beach, a Korteweg-de Vries equation type ψ_τ+6ψψ_ξ+ψ_ξξξ=−Γ(τ)ψ is derived. Since no exact analytical solution has been found to date for this equation, some remarkable cases in which the equation takes up a tractable form are analysed. Finally the interaction between cylindrical imploding and expanding waves is considered and the phase shifts caused by the head-on collision are given. This work was supported by CNR-GNFM.     

Examples of manifolds which are homogeneous spaces of lie groups of arbitrarily large dimension

We discuss the possibility for a given homogeneous space M=G/H to be diffeomorphic to each term of a sequence (G_n/H_n) of coset spaces, where the G_n 's are connected real Lie groups of arbitrarily large (finite) dimensions. We prove that this possibility does indeed arise when M is the total space of a convenient circle bundle. Typical examples are provided by odd dimensional spheres of dimension at least 3. Our main tool for this result is the theory of connections on principal bundles.     

Electronic Properties of Mono‐Substituted Tetraferrocenyl Porphyrins in Solution and on a Gold Surface: Assessment of the Influencing Factors for Photoelectrochemical Applications

Two unsymmetric meso‐tetraferrocenyl‐containing porphyrins of general formula Fc₃(FcCOR)Por (Fc=ferrocenyl, R=CH₃ or (CH₂)₅Br, Por=porphyrin) were prepared and characterized by a variety of spectroscopic methods, whereas their redox properties were investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) approaches. The mixed‐valence [Fc₃(FcCOR)Por]ⁿ⁺ (n=1,3) were investigated using spectroelectrochemical as well as chemical oxidation methods and corroborated with density functional theory (DFT) calculations. Inter‐valence charge‐transfer (IVCT) transitions in [Fc₃(FcCOR)Por]⁺ were analyzed, and the resulting data matched closely previously reported complexes and were assigned as Robin–Day class II mixed‐valence compounds. Self‐assembled monolayers (SAMs) of a thioacetyl derivative (Fc₃(FcCO(CH₂)₅SCOCH₃)Por) were also prepared and characterized. Photoelectrochemical properties of SAMs in different electrolyte systems were investigated by electrochemical techniques and photocurrent generation experiments, showing that the choice of electrolyte is critical for efficiency of redox‐active SAMs.