LaNiSi: A Symmetric Mirror Homologous Series in the La-Ni-Si System.

A series of four homologous silicides have been discovered during systematic explorations in the central part of the La-Ni-Si system at 1000 °C. All compounds LaNiSi ( = 3; = 28.8686(8), = 4.

Mode Crystallography Analysis through the Structural Phase Transition and Magnetic Critical Behavior of the Lacunar Spinel GaMoSe.

In the lacunar spinels, with the formula ABX, transition-metal ions form tightly bound B clusters resulting in exotic physical properties such as the stabilization of Néel-type skyrmion lattices, which hold great promise for energy-efficient switching devices. These properties are governed by the symmetry of these compounds with distortion of the parent noncentrosymmetric 4̅3 space group to the polar 3, with recent observation of a coexisting 2 low-temperature phase. In this study, through powder neutron diffraction, we further confirm that a metastable 2 coexists with the 3 phase in GaMoSe and we present its structure.

Magnetic and Structural Studies of G-Phase Compound MnNiSi.

Transition metal compounds with complex crystal structures tend to demonstrate interesting magnetic coupling resulting in unusual magnetic properties. In this work, the structural and magnetic characterization of a single crystal of the Ni-Mn-Si based G-phase compound, MnNiSi, grown by the Czochralski method, is reported. In this structure, isolated octahedral Mn clusters form an fcc lattice.

KO(t)Bu mediated synthesis of phenanthridinones and dibenzoazepinones.

Synthesis of substituted phenanthridinones and dibenzoazepinones has been realized from 2-halo-benzamides in the presence of potassium tert-butoxide and a catalytic amount of 1,10-phenanthroline or AIBN. This new carbon-carbon bond forming reaction gives direct access to various biaryl lactams containing six- and seven-membered rings chemoselectively. Carbon-carbon coupling seems to proceed by the generation of a radical in the amide ring which leads to C-H arylation of aniline.