Luminescence of ytterbium complexes with octaphenyltetraazaporphyrins

We have synthesized outer complexes of ytterbium with octaphenyl-and octa(para-tert-butylphenyl)tetraazaporphyrins, in which for the first time we have detected luminescence of ytterbium with maximum at 980 nm. We have shown that the 4f-luminescence quantum yield in the complexes depends primarily on the nature of the outer ligand. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 5, pp. 693–696, September–October, 2006.     

Effect of non-central interactions on energy and lattice dynamics of molecular crystals

Atom-atom, multipole-multipole and three-body potentials have been used to calculate the energy and lattice dynamics of β-paradichlorobenzene, phenanthrene and m-chloronitrobenzene. Non-central interactions are shown to give a significant contribution to the intermolecular interaction energy but have little effect on the phonon spectrum of the crystals.     

Oxidation with p-(methoxycarbonyl) perbenzqic acid 1. Stereochemistry of epoxidation of Δ5-steroids

Conclusions We have examined the dependence of the stereospecificity of epoxidation of ⁵-steroids by p-(methoxy-carbonyl) perbenzoic acid on substrate structure and solvent.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 447–449, February, 1978.     

Synthesis of macrocyclic compounds with steric barriers in macroheterocycle proceeding from (Z)-1,2,3,6-tetrahydrophthalic and phthalic acids

Using 1,2-dibromoethane, (E)-1,4-dibromo-2-butene, (Z)-1,2,3,6-tetrahydrophthalic and phthalic acids we obtained along [1+1] scheme uncommon macrocyclic compounds containing ester groups, multiple bonds, and amide moieties in the macroheterocycle. The neutralization of bis-acids with ethylenediamine gave the corresponding macrocyclic diammonium salts that on heating to the melting point were converted into the corresponding macrocyclic diamides. The structure of compounds obtained was established from the elemental analyses, IR and NMR spectra.     

On the Maximal Cut in a Random Hypergraph

Doklady Mathematics - This paper deals with the problem of finding the max-cut for random hypergraphs. We consider the classical binomial model $$H(n,k,p)$$ of a random k-uniform hypergraph on n...