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A new class of flexible energetic salts, part 2: The crystal structures of the cubane-1,4-diammonium dinitramide and cubane-1,2,4,7-tetraammonium dinitramide salts (1998)

Butcher, Ray J. ; Gilardi, R. D.

Springer

Journal of chemical crystallography 28 (1998), S. 95-104

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ISSN: 1572-8854

Schlagwort(e): Cubane structures ; substituted cubanes ; cubane ammonium salts ; dinitramide salts

Quelle: Springer Online Journal Archives 1860-2000

Thema: Geologie und Paläontologie , Physik

Notizen: Abstract The crystal structures of cubane-1,4-diammonium dinitramide, 1, and cubane-1,2,4,7-tetraammonium dinitramide, 2, have been determined. 1 crystallizes in the space group P21/c with cell dimensions a = 6.018(2), b = 11.642(3), c = 9.754(3) Å, β = 107.24(2), while 2 crystallizes in the space group P21/c with cell dimensions a = 9.401(4), b = 9.603(3), c = 12.603(4) Å, β 111.08(3). In these structures the ammonium substituents are symmetrically attached with respect to the cubane skeleton and have neither low lying empty orbitals nor available lone pairs of electrons thus they have a minimal effect on the metrical parameters of the cubane skeleton. All C–C bond lengths are close to the overall average C–C bond length for all reported cubanes of 1.559 Å. The conformations adopted by the dinitramide ions in both structures are quite different, with the bend, twist, and torsion angles for the dinitramide ion in 1 being significantly larger than those found for the dinitramide ions in 2, due to the different types of hydrogen bonding found in the two structures. In 2, the conformation adopted by the adjacent ammonium ions allows two of the three protons from each ammonium cation to form hydrogen bonds in such a manner that they span either the syn or the anti oxygen atoms of a single dinitramide anion. The dinitramide anion is thus constrained by these interactions and is less free to twist and bend. These results provide further confirmation that the metrical parameters of both the cubane and dinitramide moieties are flexible and reflect their local environment.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1023/A:1022433512219

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Digitale Medien

A new class of flexible energetic salts, part 5: The structures of two hexammonium polymorphs and the ethane-1,2-diammonium salts of dinitramide (1998)

Gilardi, R. D. ; Butcher, Ray J.

Springer

Journal of chemical crystallography 28 (1998), S. 673-681

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ISSN: 1572-8854

Schlagwort(e): Hexamine structures ; hexammonium structures ; ethane-1,2-diammonium structures ; dinitramide structures

Quelle: Springer Online Journal Archives 1860-2000

Thema: Geologie und Paläontologie , Physik

Notizen: Abstract The crystal structures of two hexammonium polymorphs, 1 and 2, and the ethane-1,2-diammonium, 3, salts of dinitramide have been determined. 1 crystallizes in the triclinic space group $${P\bar 1}$$ with cell dimensions a = 6.391(2), b = 7.5826(9), c = 10.828(1) Å, a = 77.58(1), β = 88.18 (2), γ = 87.54(2)°, 2 crystallizes in the monoclinic space group P21/c with cell dimensions a = 6.4893(3), b = 14.5149(8), c = 10.6557(4) Å, β = 94.300(4)°, and 3 crystallizes in the triclinic space group $${P\bar 1}$$ with cell dimensions a = 5.614(1), b = 6.867(2), c = 7.371(2) Å, α = 68.89(2), β = 89.00(2), γ = 78.90(2)°. The three structures all contain protonated amine cations which are involved in hydrogen bonding interactions with dinitramide anions.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1023/A:1021743916604

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Digitale Medien

Synthesis and Structural Characterization of Monomeric Zinc(II), Cadmium(II), and Mercury(II) Arenethiolates with a Chelating Oxazoline Ligand (1999)

Mugesh, G. ; Singh, Harkesh B. ; Butcher, Ray J.

Weinheim : Wiley-Blackwell

Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 1229-1236

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ISSN: 1434-1948

Schlagwort(e): Metal thiolates ; Helical chirality ; Spontaneous resolution ; Disulfide ; Intramolecular coordination ; Chemistry ; General Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: The synthesis and characterization of homoleptic zinc(II), cadmium(II), and mercury(II) thiolates derived from 4,4-dimethyl-2-phenyloxazoline (1) are described. The disulfide [Ox2S2 (3), Ox = 2-(4,4-dimethyl-2-oxazolinyl)phenyl] is prepared by the oxidation of lithium arenethiolate OxS-Li+ (2), and structurally characterized. The disulfide 3 is chiral and enantiomerically pure in the solid state. The thiolate derivatives, M[S(Ox)]2 [M = Zn (4), or Cd (5)], are prepared in good yield by the metathesis reactions of MCl2 with lithium arenethiolate 2. The mercury complex 6 is synthesized by treating 3 with elemental mercury. The complexes are quite stable and highly soluble in common nonpolar organic solvents. X-ray diffraction results show that the zinc thiolate 4 and cadmium thiolate 5 are monomeric in the solid state. The geometry around the metal ion in these two complexes is found to be distorted tetrahedral. The zinc complex is chiral and has crystallized in two different crystalline modifications. The single crystal structures have been determined for both the crystalline modifications, a monoclinic modification (4a) and an orthorhombic one (4b). The crystal structure of 4a shows that the complex is “helically” chiral and enantiomerically pure whereas the crystal structure of 4b shows the modification to be racemic. The spontaneous splitting of the racemates, which is responsible for the isolation of optically active compound, indicates that there should be some solubility differences between the racemates and pure enantiomers. 1H- and 13C-NMR measurements indicate that the complex 4 retains its “helical” structure in solution.

Zusätzliches Material: 6 Ill.

Materialart: Digitale Medien

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