1-Acyloxyaziridine-2,2-dicarboxylic acid esters

The reaction of diazomethane and O-acylisonitrosomalonates gave ²-1,2,3-triazoline-5,5-dicarboxylic acid esters, the rates of formation and thermal stabilities of which are determined by the character of ths substituent attached to the oxygen atom. Thermolysis of the triazolines leads to mixtures of 1-acyloxyaziridine-2,2-dicarboxylic acid esters and isomeric dialkyl O-acylisonitrososuccinates; acidolysis with BF₃·Et₂O makes it possible to obtain exclusively aziridines. The acidic decompositions of dimethyl 4-methyl-²-1,2,3-triazoline-5,5-dicarboxylate, which was obtained from the reaction of diazoethane and dimethyl O-tosylisonitrosomalonate, leads to dimethyl -tosyloxyamino--vinylmalonate. A dependence of the spin-spin coupling constants (SSCC) of the protons of the aziridine ring on the electronegativities of the substituents attached to the oxygen atom was observed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 338–342, March, 1984.     

Low-field DC-magnetization study of Ho-doped Mn–Zn ferrite ferrofluid

The physical and magnetic properties of magnetic nanoparticles are crucial for their effectiveness and reliability in biomedical applications. In this article, we report the synthesis of a stable Ho-substituted Mn–Zn ferrite ferrofluid and its physical and magnetic properties. Substitution by rare earth metal plays an important role in determining the magneto-crystalline anisotropy in 4f-3d inter-metallic compounds. Ho³⁺ substitution not only enhanced the magnetic anisotropy but also produced strong spin frustration at low temperature. The field dependence of blocking temperature shows H^2/3 dependency in the entire range of field, i.e., 10–700 Oe, indicating the emergence of Ising spins characteristics in the present system.     

Extraction of mineral acids with methyltrioctylammonium dinonylnaphthalenesulfonate

The interphase distribution of hydrogen halides (HF, HCl, HBr, and HI) and oxygen-containing acids (H₂SO₄ and HClO₄) in a system with the binary extracting agent methyltrioctylammonium dinonylnaphthalenesulfonate was studied. It was found in the extraction of mineral acids depending on the aqueous acidity, that the distribution ratios of mineral anions B ^m? decreased with pH in accordance of the laws of binary extraction. The extraction isotherms of mineral acids were obtained, and the apparent constants of extraction were calculated.     

Hydrazine derivatives in the synthesis of linear and heterocyclic compounds

N-Siloxycarbonylation, transamination, carboxylation, silylation, and condensation of N,N-dimethylhydrazine, 1-methyl-1-[2-(1-methylhydrazino)ethyl]hydrazine, N-methyl-2-(1-methylhydrazino)ethanamine, and some their trimethylsilyl derivatives resulted in the formation of previously unknown linear and heterocyclic compounds.     

Investigation of the structure and energetics of Β-diketonates. VIII. Molecular structure of the Ba(dpm)2 monomer according to gas phase electron diffraction data

A combined electron diffraction and mass spectrometric study of the overheated vapor over barium dipivaloylmethanate was performed. It was found that at 488°C the monomeric molecular form predominates in the vapor. The Ba(dpm)₂ molecule has D_2d symmetry. Its r_a, r_g, and r_α parameters were determined.     

S-ArylN,N-dialkylamidothiosulfates, a novel class of sulfenic acid derivatives

A method for the synthesis ofS-arylN,N-dialkylamidothiosulfates, a novel class of sulfenic acid derivatives, was proposed. The method is based on the reaction of arenesulfenyl chlorides withN,N-dialkylamidosulfinic acids or with secondary amines in liquid SO₂ in the presence of triethylamine. In the presence of halogen-containing Lewis acids,S-arylN,N-dialkyl-amidothiosulfates add to the C=C bonds to give aryl β-haloalkyl sulfides. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1484–1487, August, 2000.