Methyldiborane

Methyldiborane
Names
IUPAC name
Methyldiborane
Other names
monomethyldiborane
methylated diborane
boraethane
Identifiers
3D model (JSmol)
  • InChI=1S/CH8B2/c1-3-4-2-5-3/h3H,2H2,1H3[2]
    Key: ALTSFFGCORZGRQ-UHFFFAOYSA-N[3]
  • C[BH]1[H][BH2][H]1
Properties
CH
3BH
3BH
2
Molar mass 41.70 g mol−1
Appearance Colorless gas
Density 0.546 at -126°
Boiling point −43 °C (−45 °F; 230 K)
Related compounds
Related alkyl boranes
 dimethyldiborane
trimethyldiborane
tetramethyldiborane
trimethylborane
ethyldiborane
Related compounds
 Diborane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Methyldiborane, CH3B2H5, or monomethyldiborane is the simplest of alkyldiboranes, consisting of a methyl group substituted for a hydrogen in diborane. As with other boranes it exists in the form of a dimer with a twin hydrogen bridge that uses three-center two-electron bonding between the two boron atoms, and can be imagined as methyl borane (CH3BH2) bound to borane (BH3).[4] Other combinations of methylation occur on diborane, including 1,1-dimethylborane, 1,2-dimethyldiborane, trimethyldiborane, tetramethyldiborane, and trimethylborane (which is not a dimer). At room temperature the substance is at equilibrium between these molecules.[5]

The methylboranes were first prepared by H. I. Schlesinger and A. O. Walker in the 1930s.[6][7]

  1. ^ Jane E. Macintyre, ed. (1994-11-10). Dictionary of Organometallic Compounds. CRC Press. p. 463. ISBN 978-0-412-43060-2.
  2. ^ http://cactus.nci.nih.gov/chemical/structure/C%5BBH%5D1H%5BBH2%5DH1/stdinchi [bare URL plain text file]
  3. ^ http://cactus.nci.nih.gov/chemical/structure/C%5BBH%5D1H%5BBH2%5DH1/stdinchikey [bare URL plain text file]
  4. ^ Srebnik, Morris; Cole, Thomas E.; Brown, Herbert C. (January 1987). "Methylborane - a remarkable unhindered monoalkylborane which achieves the controlled sequential hydroboration of representative alkenes". Tetrahedron Letters. 28 (33): 3771–3774. doi:10.1016/s0040-4039(00)96380-9.
  5. ^ Cite error: The named reference bell48 was invoked but never defined (see the help page).
  6. ^ Long, L. H.; Wallbridge, M. G. H. (1965). "646. The chemistry of boron. Part VI. New preparative methods and decomposition studies relating to methyldiboranes". Journal of the Chemical Society: 3513–3520. doi:10.1039/JR9650003513. (subscription required)
  7. ^ Schlesinger, H. I.; Walker, A. O. (April 1935). "Hydrides of Boron. IV. The Methyl Derivatives of Diborane". Journal of the American Chemical Society. 57 (4): 621–625. doi:10.1021/ja01307a009.