RESUMEN
Understanding nanoscale mechanisms responsible for the recently discovered ferroelectric nematics can be helped by direct visualization of self-assembly of strongly polar molecules. Here, we report on scanning tunneling microscopy studies of monomolecular layers of a ferroelectric nematic liquid crystal on a reconstructed Au(111) surface. The monolayers are obtained by deposition from a solution at ambient conditions. The adsorbed ferroelectric nematic molecules self-assemble into regular rows with tilted orientation, resembling a layered structure of a smectic C. Remarkably, each molecular dipole in this architecture is oriented along the same direction giving rise to polar ferroelectric ordering.
RESUMEN
A novel method for synthesis of medium sized ring azasultams was proposed. It includes reductive cleavage with sodium cyanoborohydride of annulated 5,6-dihydro-2H-1,2,4-thiadiazine-1,1-dioxides that were prepared in bulk quantities by an improved procedure consisting of reacting cyclic imidates with taurine followed by treatment with phosphorus oxychloride in the presence of DIPEA.
RESUMEN
A new synthetic approach to 4-substituted imidazo[4,5-c]pyrazoles is proposed on the basis of the N'-(4-halopyrazol-5-yl)amidine cyclization under the conditions of copper-catalyzed cross-coupling reactions. Using 5-aminopyrazoles and copper catalysts as starting materials, the method is inexpensive and convenient and allows a wide range of substituents at all positions of the imidazo[4,5-c]pyrazole nucleus.