Difluoramination of Heterocyclic Ketones:  Control of Microbasicity

Chapman, Robert D.; Welker, Mark F.; Kreutzberger, Charles B.

doi:10.1021/jo9718399

Cited by 31 publications

(13 citation statements)

References 31 publications

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“…Difluoramine was generated by acidic hydrolysis of N , N ‐difluorourea, prepared by direct fluorination of aqueous urea 15, 16. A description of the difluoramine reaction set‐up and generation process was described by Chapman et al 17 1,1,4,4‐Tetranitrocyclohexane was prepared according to the method of Prakash et al 18 1,1,4,4‐Tetrakis(difluoramino)cyclohexane was prepared according to the method of Baum 19. 3,3,7,7‐Tetrakis(diflu‐oramino)octahydro‐1,5‐dinitro‐1,5‐diazocine was synthe‐sized and provided by Chapman et al 17 4,4‐Bis(difluora‐mino)‐1‐nitropiperidine and 1,4,4‐trinitropiperidine were prepared as described below.…”

Section: Methodsmentioning

confidence: 99%

Mass spectral fragmentation pathways in cyclic difluoramino and nitro compounds

et al. 2000

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The recently synthesized compounds 4, 4-bis(difluoramino)-1-nitropiperidine (I), 1,4,4-trinitropiperidine (II), 1,1,4,4-tetranitrocyclohexane (III), 1,1,4, 4-tetrakis(difluoramino)cyclohexane (IV) and 3,3,7, 7-tetrakis(difluora-mino)octahydro-1,5-dinitro-1,5-diazocine (HNFX, V) are being considered as potential energetic materials. The mass spectra of these compounds were studied using electron ionization (EI) mass spectrometry. A collision-induced dissociation (CID) study of the major EI peaks was carried out using a Finnigan TSQ 700 tandem mass spectrometer. The mass fragmentation pathways are constructed and discussed. The decomposition of HNFX (V), under EI, appeared to parallel the thermal decomposition of nitramines where N-NO(2) cleavage is often the first step. However, the two nitramines with a six-membered ring structure (I and II) underwent initial loss of a geminal substituent; loss of a nitramine nitro group was the secondary step. The two cyclohexane structures (III and IV) showed similar initial fragmentation pathways, featuring successive losses of nitro or difluoramino groups. Copyright 2000 John Wiley & Sons, Ltd.

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Section: Methodsmentioning

confidence: 99%

Mass spectral fragmentation pathways in cyclic difluoramino and nitro compounds

et al. 2000

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“…The first high-yield synthesis and structural characterization of the HNFX crystal, with stoichiometry C 6 H 8 F 8 N 8 O 4 , were carried out by Chapman et al [5,6] X-ray crystallographic analysis indicates that HNFX recrystallizes at ambient pressure and temperature from a variety of solvents in the rhombohedral space group R3∼, C3i.2, with nine molecules per unit cell (cf. Fig.…”

Section: Introductionmentioning

confidence: 99%

Organic cyclic difluoramino‐nitramines: infrared and Raman spectroscopy of 3,3,7,7‐tetrakis(difluoramino)octahydro 1,5‐dinitro‐1,5‐diazocine (HNFX)

Weck

Gobin

Kim

et al. 2009

J Raman Spectroscopy

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We present the first vibrational structure investigation of 3,3,7,7-tetrakis(difluoramino)octahydro-1,5-dinitro-1,5-diazocine (HNFX) -and, more generally, of a member of the new class of gem-bis(difluoramino)-substituted heterocyclic nitramine energetic materials -using combined theoretical and experimental approaches. Optimized molecular structure and vibrational spectra of the Ci . . . symmetry conformer constituting the HNFX crystal were computed using density functional theory methods. Fourier transform infrared and Raman spectra of HNFX crystalline samples were also collected at ambient temperature and pressure. The average deviation of calculated structural parameters from X-ray diffraction data is ∼1% at the B3LYP/6-311++G(d,p) level of theory, suggesting the absence of significant molecular distortion induced by the crystal field. Very good agreement was found between simulated and measured spectra, allowing reliable assignment of the fundamental normal modes of vibration of the HNFX crystal. Detailed analysis of the normal modes of the C-(NF 2 ) 2 and N-NO 2 moieties was performed due to their critical importance in the initial steps of the molecular homolytic fragmentation process.

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“…3,3,7,7-Tetrakis(difluoroamino)octahydro-1,5-dinitro-1,5-diazocine (HNFX), 3,3-dinitro-7,7-bis(difluoroamino)octahydro-1,5-dinitro-1,5-diazocine (TNBDFADZ) and 1,3,3,5,7,7-hexanitro-1,5-diazacyclooctane (HNDZ) are analogue energetic compounds [10][11][12][13]. The ring structures of the title compounds are similar to HMX.…”

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confidence: 99%