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The class of Zeeman topologies on spacetimes in the frame of relativity theory is considered to be of powerful intuitive justification, satisfying a sequence of properties with physical meaning, such as the group of homeomorphisms under such a topology is isomorphic to the Lorentz group and dilatations, in Minkowski spacetime, and to the group of homothetic symmetries in any curved spacetime. In this article we focus on two distinct topologies that were suggested by Zeeman as alternatives to his Fine topology, showing their connection with two orders: a timelike and a (non-causal) spacelike one. For the (non-causal) spacelike order, we introduce a partition of the null cone which gives the desired topology invariantly from the choice of the hyperplane of partition. In particular, we observe that these two orders induce topologies within the class of Zeeman topologies, while the two suggested topologies by Zeeman himself are intersection topologies of these two order topologies (respectively) with the manifold topology. We end up with a list of open questions and a discussion, comparing the topologies with bounded against those with unbounded open sets and their possible physical interpretation.

A series of RuII-based photosensitizers were synthesized and extensively characterized. The ligand utilized to coordinate ruthenium was a pyridine–quinoline hybrid bearing an anthracene moiety, and it was combined with commercially available 2,2′-bipyridine (bpy) for the heteroleptic complexes. The produced bichromophoric complexes show very strong and wide UV/Vis absorption bands. The ability of these complexes to act as triplet photosensitizers in the production of singlet oxygen was thoroughly studied by utilizing the photooxidation of 1,3-diphenylisobenzofuran as the test reaction. The most efficient photosensitizer in this new family of RuII complexes affords singlet oxygen quantum yields and production-rate efficiencies up to two times higher than those of the benchmark [Ru(bpy)3]2+ parent complex.

The ability of chiral β-amino alcohols to catalyze the direct asymmetric aldol reaction was evaluated for the first time in aqueous micellar media. A family of cheap and easily accessible β-amino alcohols, obtained in one step from naturally occurring amino acids, was shown to successfully catalyze the asymmetric aldol reaction between a series of ketones and aromatic aldehydes. These aldol reactions furnished the corresponding β-hydroxy ketones with up to 93% isolated yield and 89% ee. (S)-2-phenylglycinol and Triton X-100 proved to be the best organocatalyst and surfactant, respectively. Chirality 25:119–125, 2013. © 2012 Wiley Periodicals, Inc.

In this study we show that nanoparticles of various ferric oxides (hematite, maghemite, amorphous Fe2O3, β-Fe2O3 and ferrihydrite) incorporated into carbon paste exhibit electro-catalytic properties towards hydrogen peroxide reduction. The modified paste electrode performances were evaluated and compared with those obtained with Prussian Blue-modified carbon paste electrode, which represents an excellent chemical mediator towards the H2O2 redox reaction (as widely described in literature). The best catalytic activity was found for carbon paste modified by amorphous ferric oxide with 2–4 nm particle size, which was further tested for possible application as hydrogen peroxide sensor. At pH 7, the limit of detection was 2×10−5 M H2O2 (S/N=3), the calibration curves were linear upto 8.5 mM H2O2 (R2=0.998), the measurement reproducibility (RSD=97%, n=4), the interelectrode reproducibility (RSD=16%, nelectrodes=5) and

Asymmetric Michael addition of lithiated methyl ketone SAMP hydrazones (S)-3 to a variety of alkenylphosphonates (E)-2 followed by oxidative cleavage of the 1,4-adducts (S,S)-4 by ozonolysis afforded 2-substituted 4-oxophosphonates (S)-5 in usually moderate to very good overall yields (14–77%) and with mostly high enantiomeric excesses (ee = 20–>95%). In addition, asymmetric Michael Michael tandem additions were carried out in good overall yields by trapping the intermediate lithio phosphonate anions with alkenylphosphonate or enoate Michael acceptors.

Asymmetric Michael addition of lithiated SAMP hydrazones ( S )- 2 to a variety of alkenylphosphonates ( E )- 3 followed by oxidative cleavage of the 1,4-adducts 4 afforded 2,3-disubstituted 4-oxophosphonates 5 with good to very good yields (58–80%), low to moderate diastereomeric ( de = 6–74%) and excellent enantiomeric excesses ( ee = >93%). Pure anti -diastereomers ( ee = >93%) of 5 were obtained by separation of the stereoisomers by H PLC. In addition, the lithiated SAMP hydrazone ( S )- 2a was added to alkenylphosphonates ( E )- 3 , and the lithio phosphonate anions were trapped with alkyl halides or sulfates, yielding 1,2-disubstituted 4-oxophosphonates 8 with moderate to good yields (38–69%), low to good diastereomeric ( de = 10–77%) and high enantiomeric excesses ( ee = >90%) after oxidative cleavage.

The racemic and enantioselective synthesis of a novel glyceric acid derivative, namely, 2,3-dihydroxy-3-(3,4-dihydroxyphenyl)-propionic acid as well as the antioxidant activities is described. The virtually pure enantiomers, (+)-(2R,3S)-2,3-dihydroxy-3-(3,4-dihydroxyphenyl)-propionic acid and (-)-(2S,3R)-2,3-dihydroxy-3-(3,4-dihydroxyphenyl)-propionic acid were synthesized for the first time via Sharpless asymmetric dihydroxylation of trans-caffeic acid derivatives using the enantiocomplementary catalysts, (DHQD)(2)-PHAL and (DHQ)(2)-PHAL. The determination of enantiomeric purity of the novel chiral glyceric acid derivatives was performed by high-performance liquid chromatographic techniques on the stage of their alkylated precursors. The novel glyceric acid derivatives show strong antioxidant activity against hypochlorite and N,N-diphenyl-N-picryl-hydrazyl free radical. Their antioxidant activity is about 40-fold higher than that of the corresponding natural polyether and three-fold higher of trans-caffeic acid itself.

Lucigenin (N,N′-dimethyl-9,9′-biacridinium nitrate) 1 on heating under reflux in protic solvents in the presence of amines gives rise to the N,N′-dimethyl-9,9′-biacridylidene 2 (DBA) or protected hemiaminal N-methoxymethyl-9,9′-bi-acridylidene 3. On the other hand acid hydrolysis and synchronous oxidation of hemiaminal 3 followed by reaction of monomethyl-biacridinium nitrate 4 with sodium hydroxide in methanol or water leads to biacridine 5 (overall yield ca. 33%).