[New plastic materials and problems in their processing for dental prostheses].

A study into the use of a chiral phase-transfer catalyst in conjunction with acetone cyanohydrin to effect the enantioselective formation of alpha-amino nitriles from alpha-amido sulfones is described. This novel catalytic asymmetric Strecker reaction is analyzed with regard to the possible mechanistic basis.

Carbonates↗

PubMed2006

Neutron diffraction and simulation studies of CsNO3 and Cs2CO3 solutions.

Neutron diffraction with isotopic substitution (NDIS) experiments and molecular dynamics (MD) simulations have been used to study the structuring in aqueous solution of two cesium salts, cesium carbonate, and cesium nitrate. As was previously found for guanidinium salts of carbonate, mesoscopic-scale clusters were seen to form in the Cs2CO3 solution both in the MD simulations and in the diffraction experiments. No such large scale ion clusters were found in the CsNO3 solutions in either the modeling or experiments. The results are dominated by the strength and geometry of the direct first-neighbor interactions, which explain the differences in the clustering behavior between the two solutions without need to refer to longer-range water-water structuring.

Carbonates↗

PubMed2006

Functionalization of single-wall carbon nanotubes by tandem high-pressure/Cr(CO)6 activation of Diels-Alder cycloaddition.

An original method to induce Diels-Alder cycloadditions on carbon nanotubes is reported. The process is based on the double activation of the nanotube surface by combining high pressure and Cr(CO)6. This allows the efficient functionalization of carbon nanotubes by electron-rich dienes.

Carbonates↗