New limits on magnetic monopoles searches from accelerator and nonaccelerator experiments

Here, the status of the searches for “classical Dirac” magnetic monopoles (MMs) at accelerators and for GUT MMs in the cosmic radiation is discussed. We present recent analysis for classical Dirac monopoles at accelerators and the lowest flux upper limit for MMs in the mass range 10⁵–10¹² GeV obtained with the SLIM experiment at the Chacaltaya high-altitude-laboratory (5290 m a.s.l.). The text was submitted by the author in English.     

A poly(ethylene glycol)-supported quaternary ammonium salt: An efficient, recoverable, and recyclable phase-transfer catalyst

A quaternary ammonium salt readily immobilized on a soluble poly(ethylene glycol) polymer support efficiently catalyzes different reactions carried out under phase-transfer catalysis conditions; the catalyst, easily recovered by precipitation and filtration, shows no appreciable loss of activity when recycled three times.     

From QCA (Quantum Cellular Automata) to Organocatalytic Reactions with Stabilized Carbenium Ions

What do quantum cellular automata (QCA), “on water” reactions, and S_N1‐type organocatalytic transformations have in common? The link between these distant arguments is the practical access to useful intermediates and key products through the use of stabilized carbenium ions. Over 10 years, starting with a carbenium ion bearing a ferrocenyl group, to the 1,3‐benzodithiolylium carbenium ion, our group has exploited the use of these intermediates in useful and practical synthetic transformations. In particular, we have applied the use of carbenium ions to stereoselective organocatalytic alkylation reactions, showing a possible solution for the “holy grail of organocatalysis”. Examples of the use of these quite stabilized intermediates are now also considered in organometallic chemistry. On the other hand, the stable carbenium ions are also applied to tailored molecules adapted to quantum cellular automata, a new possible paradigm for computation. Carbenium ions are not a problem, they can be a/the solution!

     

An experimental re-investigation of the role of aromatic-aromatic interactions in a templated synthesis of a macrocyclic pseudopeptide

The experimental re-investigation of a reported synthesis of a macrocyclic pseudopeptide promoted by bis(tetrabutylammonium)terephthalate allowed us to elucidate the nature of the non-bonding interactions between the reagents and the template; while the involvement of aromatic-aromatic interactions could be ruled out, the relevance of the role of the carboxylate ion was confirmed.