Synthesis of 3(5)-(Nitroamino)-1,2,4-triazol-5(3)-carboxylic Acid and Its Ethyl Ester

Russian Journal of Organic Chemistry -     

First-order phase transition to a reentrant state in a dilute anisotropic ferrimagnet

The temperature dependence of the magnetic contribution to the specific heat of the anisotropic reentrant ferromagnet Li_0.475Co_0.05Fe_1.575Ga_0.9O₄ with freezing temperature T _f =80 K is investigated. It is found that for both T<T _f and T T _f right up to T∼150 K the function C _m (T) is described by the spin-wave law T ^3/2, but an anomaly, exhibiting features which are characteristic for a first-order thermodynamic phase transition, is observed in C _m (T ^3/2) at T=T _f . Pis’ma Zh. éksp. Teor. Fiz. 64, No. 6, 412–415 (25 September 1996)     

Limit theorems for maximum functionals of asymptotically normal sums of independent random variables

Translated from Problemy Ustoichivosti Stokhasticheskikh Modelei — Trudy Seminara, pp. 91–100, 1985.     

Products of the reaction of anabasine with phosgene

Conclusions The reaction of anabasine with phosgene has given the anabasinium salt of phosgene, anabasine-N-carbonyl chloride, and the urea derivative N,N-carbonyldianabasine. In addition to the formation of these substances, the pyridine ring of anabasine is cleaved, giving the red substance 1-chloro-5-chloroformyl-amino-2-piperidin-2-yl)penta-1,3-diene.Zaporozhe Branch, Donets Institute of Soviet Trade. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 571–574, September–October, 1970.     

Pt-containing pillared clay catalysts for CO oxidation

Platinum has been introduced into pillared clay as a complex with the organosilicon amine N’-[3-(trimethoxysilyl)propyl]diethyltriamine, as a complex with the organosilicon amine and zirconyl chloride, as an ammine complex, and by impregnation with a chloroplatinic acid solution followed by hydrogen reduction. The catalytic activity of the Pt-containing clays in CO oxidation in excess hydrogen was also studied. The last procedure yields the most active Pt-containing pillared clay. Calcium has been introduced into pillared clay by ion exchange, and it was found that the catalytic activity of the clay decreases with increasing Ca content.     

Metal complexes of polymeric tetrapyrazinoporphyrazine of the network structure: III. Catalytic properties

The catalytic properties of complexes of network polytetrapyrazinoporphyrazine with Cu²⁺, Co²⁺, and Fe²⁺ in the decomposition of hydrogen peroxide under heterogeneous conditions were studied. These compounds exhibit catalytic activity which depends on the nature of a metal ion. A comparison of the catalytic properties of the monomeric and polymeric isometallic complexes of tetrapyrazinoporphyrazine reveals an activating effect of the giant conjugated system of the polymeric macroligand.     

Structure and spectroluminescence properties of derivatives of 1,8-naphthoylene-1',2-benzimidazole with substituents of various electronic types

A series of quantum-chemical calculations using the CNO SCF CI method were carried out to account for the nontraditional influence of substituents of various electronic types on the spectroluminescence characteristics of naphthoylenebenzimidazole. It is shown that the principal direction of electron-density redistribution during excitation of this molecule is the charge transfer from its benzene fragment to its naphthalene fragment, and the most appreciable change in spectrofluorescence characteristics compared to the unsubstituted compound is achieved by introducing electron-donor substituents into the benzimidazole fragment, and in electronacceptor characteristics, into the naphthalene fragment of the naphthoylenebenzimidazole molecule.Institute of Single-Crystals, National Academy of Sciences of Ukraine, Khar'kov 310001 and Khar'kov State University, Khar'kov 310077. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 633-639, May, 1995. Original article submitted Anril 10. 1995.