The first synthesis of tetrahydrobenzo[b]pyrrolo[2,1-f][1,6]naphthyridine by the Michael addition of butyn-2-one to 1-(2-methoxycarbonylvinyl)tetrahydrobenzo[b][1,6]naphthyridine

Russian Chemical Bulletin -     

Shape of the ferromagnetic resonance absorption band of textured powder samples of maghemite

The shape of the ferromagnetic resonance absorption band of powder microcrystalline ferrite γ-Fe₂O₃ has been studied. Samples in the form of a ferromagnetic fluid have been subjected to preliminary particle orientation and frozen in a magnetic field. The shape of the absorption bands has been computer processed with allowance for the anisotropy of the shape of particles and their spatial cubic anisotropy, as well as for the contribution from nondispersed fraction of the bulk of the powder. Satisfactory agreement with the experiment has been obtained for several orientations of the measuring magnetic field with respect to the preliminary orientation.     

Deposition of protective-decorative coatings onto aluminum alloys

Technique for deposition of a nickel coating onto various aluminum alloys was developed. This coating can be used both independently and as a sublayer under multilayer coatings and, in particular, under those of nickel, tin–bismuth, lustrous nickel, and lustrous chromium. The technique includes anodization, chemical treatment, and electrodeposition of nickel in a special solution. The working modes of the anodization electrolyte were chosen and the necessity for a preliminary chemical treatment of the oxide film being formed was substantiated. A composition of the acid electrolyte for the subsequent nickel plating was developed with buffer and improving additives. The thus deposited electroplated nickel coatings exhibit a high adhesion to the aluminum base without additional thermal treatment. This makes it possible not only to reduce the technological time for deposition of the subsequent multilayer coatings, but also to fully automate the whole process.     

Mechanical behavior of Ti-Zr-Ni quasicrystals during nanoindentation

The parameters and mechanisms of deformation of a Ti_41.5Zr_41.5Ni₁₇ quasicrystal and a W + 12 at. % Ta single crystal under nanoindentation conditions were studied and compared. It was found that, initially, the deformation of the quasicrystal is elastoplastic; however, beginning from a certain critical load, the deformation acquires a steplike character with alternating segments of slow elastoplastic deformation and rapid plastic deformation. A qualitative model is proposed for the plastic deformation of quasicrystals during nanoindentation.     

Synthesis of Dehydroabietic Chloride

The possibility of converting dehydroabietic acid into the chloride by treatment with SOCl₂, PCl₃, and PCl₅ was examined.     

Reaction of trimethylsilylpropynal with dialkylamines

Conclusions The reaction of trimethylsilylpropynal with dialkylamines is accompanied by heterolysis of the Si-C_sp bond and formation of -aminoacroleins.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1866–1868, August, 1987.