Modification of phenothiazine and carbazole derivatives with trifluoromethyl-containing 1,3,5-oxadiazines and imidazolidinediones

Russian Chemical Bulletin - Modification of phenothiazine and carbazole derivatives with trifluoromethyl-containing 1,3,5-oxadiazines and imidazolidinediones based on the copper(I)-catalyzed...     

Features of the complexation of octadecane-2,4-dione and lanthanide ions in Langmuir monolayers

Monolayers of octadecane-2,4-dione on the surfaces of EuCl₃ and TbCl₃ solutions in the concentration range of 1 × 10^–4 to 5 × 10^–3 M at pH 5.8 are studied. It is found that the limiting area of octadecane-2,4-dione molecule in a monolayer dependence on Eu³⁺ and Tb³⁺ concentration is of extreme nature. The formation of complex compounds in the ligand monolayer is postulated, and structures are proposed for these compounds at different concentrations of metal ions.     

Fluorinated 1,4,2-Oxazaphospholines and their Opening by Nucleophiles

We have found that fluorinated 1,4,2-oxazaphospholines are highly electrophilic phosphorylation reagents for alcohols, thiols, amines, and dialkyl phosphites. Phosphorylation proceeds by opening of the P-O bond to yield the corresponding phosphinates.     

Modification of gamma-carbolines with N-substituted propionamides as a new approach to mitoprotective agents

An approach to the modification of biologically active gamma-carbolines with the N-substituted propionamide fragments by the reaction of N-substituted acrylamides with gamma-carbolines catalyzed by cesium fluoride has been suggested. The compounds synthesized were studied for the influence on the functional characteristics of brain mitochondria, in particular, on the membrane potential, calcium-induced “swelling” and calcium capasity of the rat brain mitochondria.     

Synthesis of spiro[imidazole-4,3'-thiochroman]ones from [2-(benzylsulfanyl)benzylidene]imidazolones

Chemistry of Heterocyclic Compounds - A methodology was developed for the synthesis of phenylspiro[imidazole-4,3'-thiochroman]ones by treatment of [2-(benzylsulfanyl)-benzylidene]imidazolones...     

Effect of low-temperature annealing on the magnetization curve of YBa<Subscript>2</Subscript>Cu<Subscript>3</Subscript>O<Subscript>6 + <Emphasis Type="Italic">x</Emphasis></Subscript> ceramics

The effect of low-temperature annealing on the magnetization curve of YBa₂Cu₃O_{6 + x} ceramics in the superconducting state (x ≈ 0.9) is investigated. When the annealing time is fairly long, the field dependence of magnetic moment M exhibits a feature in the form of a plateau, where the value of M remains almost constant. The evolution of this feature in the magnetization curves of annealed samples with annealing time and temperature is studied. It is assumed that low-temperature annealing gives rise to metastable ferromagnetic clusters in YBa₂Cu₃O_{6 + x} ceramics, the contribution of which to the magnetic moment accounts for the feature in the magnetization curves of the annealed samples.     

Zeeman effect and stark splitting of the electronic states of the rare-earth ion in the paramagnetic terbium garnets Tb<Subscript>3</Subscript>Ga<Subscript>5</Subscript>O<Subscript>12</Subscript> and Tb<Subscript>3</Subscript>Al<Subscript>5</Subscript>O<Subscript>12</Subscript>

The Zeeman effect in the ⁷ F ₆ → ⁵ D ₄ absorption band of the Tb³⁺ ion in the paramagnetic garnets Tb₃Ga₅O₁₂ and Tb₃Al₅O₁₂ was studied. The field dependences of the Zeeman splitting of some absorption lines are found to exhibit unusual behavior: as the magnetic field increases, the band splitting decreases rather than increases. Symmetry analysis relates these lines to 4f → 4f electron transitions of the doublet-quasi-doublet or quasi-doublet-doublet type, for which the field dependences of the splitting differ radically from the well-known field dependences of the Zeeman splitting for quasi-doublet-quasi-doublet or quasi-doublet-singlet transitions in a longitudinal magnetic field.