Kinetics of Thermal Decomposition of 3,7-Dinitro-1,3,5,7-tetraazabicyclo[3.3.1]nonane

Russian Journal of General Chemistry - The kinetics of thermal decomposition of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3.3.1]nonane has been studied in solid phase and in solution. The mechanism,...     

Nitrogen-15 studies of the mechanisms of acetolyses of hexamethylenetetramine and 3,7-diacetyl-1,3,5,7-tetraazabicyclo[3.3.1]nonane (DAPT)

[¹⁵N₄]-Hexamethylenetetramine (Hexamine), and [¹⁵N₄]-3,7-diacetyl-1,3,5,7-tetraazabicyclo[3.3.1]nonane(DAPT) have been prepared starting from ¹⁵NH₃. Synthetic acetolysis reactions were performed using mixtures of pure [¹⁵N₄]- and [¹⁴N₄]-compounds and the destination of the nitrogen isotopes in the products was determined mass spectrometrically. The results show that relatively little isotopic mixing occurs in the acetolysis of hexamine to DAPT though the formation of some products with isotopic composition [¹⁴N₃¹⁵N₁] and [¹⁴N₁¹⁵N₃] indicates limited ring cleavage. However the more severe conditions used in the formation of 1,3,5-triacetyl-1,3,5-triazacyclohexane (TRAT) give rise to considerable isotopic scrambling. The acetolysis of DAPT to give 1,3,5,7-tetraacetyl-1,3,5,7-tetraazacyclooctane occurs by selective cleavage of the methylene bridge.     

Investigation of the Effect of Metallic Lewis Acid on the Nitrolysis of [3,7-Diacetyl-1,3,5,7-tetraazabicyclo(3.3.1)-nonane] and Hexamine

The effect of metallic ions on the nitrolysis of DAPT [3,7‐diacetyl‐1,3,5,7‐tetraazabicyclo(3.3.1)nonane] and HA (hexamine) was investigated by experimental and theoretical approaches. The combinatorial reagent, M(NO^?₃)_n/Ac₂/NH₄NO₃ (M=Mg²⁺, Cu²⁺, Pb²⁺, Bi³⁺, Fe³⁺ and Zr⁴⁺), was found to be efficient in the experiment of the nitrolysis of DAPT. A key intermediate during the nitrolysis of DAPT was detected by ¹H NMR. The formation mechanism of the intermediate was proposed and analyzed. Some discrepant results for the nitrolysis of DAPT and HA catalyzed by different metallic nitrates were explained based on hard‐soft and acid‐base principle and stabilized energy of ion‐complex. From the latter point of view, some cations with high polarizable ligands, e.g., OSO₂CF₃^?, (CF₃SO₂)₂N^?, and (C₄F₉SO₂)₂N^?, can increase the yields. Two newly designed catalysts, Cu[(CF₃SO₂)₂N]₂ and Cu[(C₄F₉SO₂)₂N]₂, were tested to be highly efficient.     

The gas-phase conformation of 3,7-dimethyl-3,7-diazabicyclo[3.3.1]nonane

The gas-phase conformation of the title compound (1) is discussed in reference to its photoelectron spectrum. The experimental lone-pair/lone-pair splitting (0.51 eV), when compared with that of similar diamines and with the results of three sets of MO calculations (MINDO/3, MNDO and STO-3G), leads to the conclusion that 1 exists in the chair-chair conformation. A remarkable sensitivity of the calculations to slight changes in the geometry is noted, and it is suggested that calculations of this type must include geometry-optimization. The question of through-space vs through-bond inteaction of the nitrogen lone pairs was explored by performing MNDO calculations in which the N-N resonance integrals were set to zero. These calculations indicate that in the chair-chair conformation the N-N interaction is mainly through-space. The ¹³CNMR and Ni(acac)₂-induced ¹³C shifts of 1 are discussed.     

pH-Sensitive liposomes with embedded 3,7-diazabicyclo[3.3.1]nonane derivative

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Synthesis and structure of new 3,7-diazabicyclo[3.3.1]nonane derivatives

Aminomethylation of triethylammonium 4-aryl-3,5-dicyano-6-oxo-1,4,5,6-tetrahydropyridin-2-olates and their sulfur and selenium analogs, as well as the structure of formed products, were studied in details. The reaction is of general character and leads to the formation of 7-substituted 9-aryl-2,4-dioxo-, 9-aryl-4-oxo-2-thioxo-, 9-aryl-4-oxo-2-selenoxo-3,7-diazabicyclo[3.3.1]nonane derivatives or their salts. The structures of ethyl 9-(2-chlorophenyl)-5-cyano-7-(4-methylphenyl)-2-oxo-4-thioxo-3,7-diazabicyclo[3.3.1]nonane-1-carboxylate (as a complex with N-methylmorpholine) and triethylammonium salt of 7-benzyl-4-oxo-2-selenoxo-9-(2-thienyl)-3,7-diazabicyclo[3.3.1]nonane-1,5-dicarbonitrile were studied by X-ray crystallography.     

Mechanism of transannular iodination of 3,7-dimethylenebicyclo[3.3.1]nonane derivatives

The kinetics of iodination of 3,7-dimethylenebicyclo[3.3.1]nonane derivatives containing alkyl substituents in one of the methylene groups were studied. The processes proceed selectively with the formation of 1-iodomethyl-3-iodoadamantanes, substituted at the 2-position, and characterized by a negative temperature dependence of the reaction rate (H=–(10–24) kJ/mole). The entropy contributions of the substituents at the double bonds to the reaction kinetics were determined; these contributions completely satisfy the Benson rules for synchronous transformations. A scheme of reaction mechanism was proposed, including the successive formation of diolefin complexes with iodine with a 11 and 12 compositions, a synchronous stage of ring closure with the formation of an ionic pair, and its recombination (the molecular-ionic mechanism).Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 22, No. 6, pp. 743–747, November–December, 1986.     

Selective ring opening reactions of 3,7-diarylsulfonyl-1,3,5,7-tetrazabicyclo[3.3.1] nonaries

The selective formation of 1,3,5,7-tetrazacyelooctanes from the title compounds is described. Exclusive cleavage of the IN-CH₂-N bonds at the bridge methylene is shown to be a facile process, thus providing a convenient route to tetrazacyclooctane derivatives.     

Synthesis,crystal and molecular structure of 3,7-ditosyl-1,5-diphenyl-3,7-diazabicyclo[3.3.1]nonane

3,7-Ditosyl-1,5-diphenyl-3,7-diazabicyclo[3.3.1]nonane has been found to adopt a chair–chair conformation in the crystalline state in contrast to 3,7-ditosyl-1,5-diphenyl-3,7-diazabicyclo[3.3.1]nonan-9-one, which had been previously found to exist in a chair-boat conformation.