Kinetics and Mechanism of Monomolecular Heterolysis of Commercial Organohalogen Compounds: XXVIII. Effect of the Nature of the Verdazyl Indicator on Salt Effects in Dehydrobromination of 3-Bromocyclohexene in Nitrobenzene

The salt effect on the rate of dehydrobromination of 3-bromocyclohexene in PhNO2 depends on the nature of the verdazyl indicator. With triphenylverdazyl and its chloro and nitro derivatives in the presence of Et₄NClO₄, a normal salt effect is observed, in the presence of bromides, a superposition of normal and special salt effects, while in the presence of chlorides, a superposition of normal and special negative salt effects. With the dimethoxy verdazyl derivative, a normal salt effect is always observed.     

Damping width of double resonances

Damping width of the double giant dipole resonance of ¹³⁶Xe excited in relativistic heavy ion collisions is calculated by diagonalizing a microscopic Hamiltonian in a basis containing one-, two- and three-phonon states. The coupling between these states is determined making use of the fermion structure of the phonons. The resulting width of the double giant dipole resonance is close to \(\left( {3_1^ + } \right)\) times the width of the single giant dipole resonance.     

Influence of electronegative substituents on the electronic spectra of the porphyrins in the form of dications

The positions of the electronic absorption bands and also the intensities of the Soret bands of the porphyrins with ethoxycarbonyl substituents in the form of dications have been calculated by the LCAO MO method in Huckel's approximation. Comparison with the experimental results shows good agreement.     

Formylporphyrins and their derivatives in the chemistry of porphyrins (review)

Data on the synthesis and chemical transformations of formylporphyrins obtained with the Vilsmeier reaction are generalized in the review. Special attention is focused on synthesis of dimeric porphyrins.     

Thermally initiated frontal polymerization of transition metal nitrate acrylamide complexes

The effect of the thermally initiated frontal polymerization of acrylamide complexes of transition metal nitrates such as those of Mn(II), Co(II), Ni(II), and Zn(II) was disclosed. The rate of the polymerization front propagation was found to be 2?9 × 10^?2cm/c, depending appreciably on sample diameter and density, as well as the presence of radical inhibitor additives. The rate was found to decrease in the series: Co(II) > Ni(II) > Mn(II) > Zn(II). Polymerization was shown to occur directly in the melting region of a complex at 80–100°C to give three-dimensional polymers. A mechanism of the polymerization being initiated with the products of the partial nitrate group decomposition was proposed. © 1994 John Wiley & Sons, Inc.     

Thermal polymerization of acrylamide during the formation of the structures of acrylamide complexes with metal nitrates

The effects of the composition of Mn^II, Co^II or Ni^II nitrate hydrate — acrylamide (AAM) mixtures and of the duration of their aging at ambient temperature on the structurization of acrylamide complexes and on the character of their thermal polymerization have been studied by scanning and isothermic differential calorimetry. Structurization is a rather prolonged step in the synthesis of acrylamide complexes. The peculiarities and rate of this step are determined by the composition of the mixture and by the nature of the complexforming compound; it yields several structural modifications of the AAM complexes. The thermal polymerization of those structural forms of acrylamide complexes that polymerize at low temperatures may be formally described as polymerization in an acrylamide-nitrate-water mixture. The effective activation energy of the polymerization of acrylamide mixed with Mn^II nitrate hydrate is 45 kJ mol^–1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 679–683, April, 1995.This work was carried out with financial support from the Russian Foundation for Basic Research, Project No. 93-03-4162.     

Porphyrins. 35. Unusual course of the Vilsmeirr reaction when formylating the platinum complex of octaethylporphyrin (revision of the known reaction)

The formation of complexes of -formyl-heptaethylporphyrin and -(2-formylvinyl)-heptaethylporphyrin in addition to the expected mesoformylporphyrin was detected when formylating the platinum complex of actaethylporphyrin by the Wilsmeier reaction. A possible mechanism is proposed for the unusual formation of similar compounds.Institute of Biomedicinal Chemistry, Russian Academy of Medical Sciences, Moscow 119832. Translated from Khimiya Geterotskilicheskikh Soedinenii, No. 3, pp. 324–328, March, 1997.     

Some hydrazides and hydrazones based on N-aminomorpholine and N-aminopiperidine

Some new hydrazides and hydrazones based on N-aminomorpholine and N-aminopiperidine have been synthesized and their antibacterial properties studied.     

Dialkylamino- and alkoxytrialkylstannanes as reagents for synthesis of organoboryl (trialkylsilyl) ketenes

Dialkylamino- and alkoxytrialkylstannanes have been studied as N- and O-nucleophilic reagents in substitution reactions at the B-Br bond. The previously unknown bis(dialkylamino)- and dialkoxyboryl trialkylsilyl ketenes were synthesized. Some peculiarities of the reactivity of these compounds have been studied.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 911–915, May, 1994.This research was carried out in the framework of the Universities of Russia State Program.     

The local characteristics of the bound states of muonic molecules

The sticking probabilities ^Jv,G- and-factors for all bound states of mesic molecules ppµ, pdµ, ptµ, ddµ, dtµ, and ttµ withJ=0 andv=0, 1 have been calculated in the adiabatic hyperspherical approach (AHSA).