No abstract

A convenient way to modify calix[4]arenes based on the direct C-C coupling reaction of their phenol moiety with 1,2,4-triazines has been advanced, and the ability of modified calixarenes to provide transport of La3+ and Ga3+ cations through organic membranes has been examined.

A new synthetic approach to condensed 1,2,4-triazines based on using the tandem A N -S N ipso and S N H -S N ipso reactions has been developed. 5-Methoxy-3-penyl-1,2,4-triazine and its N 1 -methyl quaternary salt were found to react with C,N-, C,O-and N,N'-bifunctional nucleophiles (m-phenylenediamine, resorcinol, semicarbazide and ureas) into triazacarbazoles, benzofuro[2,3-e][1,2,4]-triazines, and 6-azapurine derivatives. In all cases nucleophiles attack first the unsubstituted C-6 carbon of the triazine ring, while the final stage is replacement of the methoxy group affording cyclization products.

We investigate spin-dependent transport in multiterminal mesoscopic cavities with spin-orbit coupling. Focusing on a three-terminal set-up we show how injecting a pure spin current or a polarized current from one terminal generates additional charge current and/or voltage across the two output terminals. When the injected current is a pure spin current, a single measurement allows us to extract the spin conductance of the cavity. The situation is more complicated for a polarized injected current, and we show in this case how two purely electrical measurements on the output currents give the amount of current that is solely due to spin-orbit interaction. This allows us to extract the spin conductance of the device in this case as well. We use random matrix theory to show that the spin conductance of chaotic ballistic cavities fluctuates universally about zero mesoscopic average and describe experimental implementations of mesoscopic spin to charge current converters.

No abstract