Polynitroethyl- and Fluorodinitroethyl Substituted Boron Esters

Authors

  • Prof. Dr. Thomas M. Klapötke,

    Corresponding author
    1. Department of Chemistry, Ludwig-Maximilian University of Munich, Butenandtstr. 5–13 (D), 81377 Munich (Germany), Fax: (+49) 89-2180-77492
    • Department of Chemistry, Ludwig-Maximilian University of Munich, Butenandtstr. 5–13 (D), 81377 Munich (Germany), Fax: (+49) 89-2180-77492
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  • Dr. Burkhard Krumm,

    1. Department of Chemistry, Ludwig-Maximilian University of Munich, Butenandtstr. 5–13 (D), 81377 Munich (Germany), Fax: (+49) 89-2180-77492
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  • Richard Moll

    1. Department of Chemistry, Ludwig-Maximilian University of Munich, Butenandtstr. 5–13 (D), 81377 Munich (Germany), Fax: (+49) 89-2180-77492
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Abstract

The reaction of boron oxide with various nitro-substituted ethanols (2-nitroethanol, 2-fluoro-2,2-dinitroethanol, 2,2,2-trinitroethanol) furnished the corresponding nitroethyl borates B(OCH2CH2NO2)3 (1), B(OCH2CF(NO2)2)3 (2), and B(OCH2C(NO2)3)3 (3). Fluorination of the anion [(NO2)2CCH2OH] (4) resulted in 2-fluoro-2,2-dinitroethanol (5), a precursor for 2, and was thoroughly characterized. An interesting condensation was observed with the anion 4 to form the unusual dianion [(NO2)2CCH2C(NO2)2]2− (6). All compounds were fully characterized by multinuclear NMR spectroscopy, vibrational spectroscopy (IR, Raman), mass spectrometry and elemental analysis. The chemical, physical and energetic properties of 13 and 5 are reported, as well as quantum chemical calculations at the CBS-4M level of theory to predict the enthalpies and energies of formation. X-ray diffraction studies were performed, and the crystal structures for compounds 16 were determined and discussed thoroughly. The boron esters 13 are of interest as possible candidates for smoke-free, green colorants in pyrotechnic applications, and in case of 2 and 3 also as promising high energy oxidizers.

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