Beryllium borohydride

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Beryllium borohydride
Beryllium-borohydride-chain-from-xtal-3D-bs-17.png
Beryllium-borohydride-xtal-packing-3D-bs-17.png
  Beryllium
  Boron
  Hydrogen
Names
IUPAC name
Beryllium borohydride
Other names
Beryllium tetrahydroborate(1−), Beryllium tetrahydroborate(III)
Identifiers
3D model (JSmol)
PubChem CID
UNII
  • InChI=1S/2BH4.Be/h2*1H4;/q2*-1;+2
    Key: ONQXRAXVSQRPSX-UHFFFAOYSA-N
  • [Be+2].[BH4-].[BH4-]
Properties
Be[BH4]2
Molar mass 38.70 g·mol−1
Appearancewhite crystals
Density 0.604 g/cm3
Melting point 91.3 °C (196.3 °F; 364.4 K)
Boiling point 123 °C (253 °F; 396 K) decomposes
reacts
Solubility soluble in benzene, diethyl ether
Structure
tetragonal
I41cd, No. 110
Thermochemistry
−108 kJ/mol
Hazards
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 0.002 mg/m3
C 0.005 mg/m3 (30 minutes), with a maximum peak of 0.025 mg/m3 (as Be) [1]
REL (Recommended)
Ca C 0.0005 mg/m3 (as Be) [1]
IDLH (Immediate danger)
Ca [4 mg/m3 (as Be)] [1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Beryllium borohydride is an inorganic compound with the chemical formula Be [ B H 4]2. [2]

Contents

Preparation

Beryllium borohydride is formed by the reaction of beryllium hydride with diborane in an ether solution.

It can also be formed by the reaction of beryllium chloride and lithium borohydride in a sealed tube at 120 °C: [2]

BeCl2 + 2 Li[BH4] → Be[BH4]2 + 2 LiCl

Structure

The chemical formula of beryllium borohydride can be written as Be2+([BH4])2. The crystal structure is made up of a helical polymer of BH4Be and BH4 structure units. [2] [3] The borohydride ions, [BH4], adopt a tetrahedral geometry. [3] Beryllium is 6-coordinate and adopts a distorted trigonal prismatic geometry. [2]

Application

The purest beryllium hydride is obtained by the reaction of triphenylphosphine, PPh 3, with beryllium borohydride, Be[BH4]2 at 180 °C: [2]

Be[BH4]2 + 2 PPh3 → 2 Ph3P+BH3 + BeH2

Related Research Articles

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Diborane(6), commonly known as diborane, is the chemical compound with the formula B2H6. It is a toxic, colorless, and pyrophoric gas with a repulsively sweet odor. Given its simple formula, borane is a fundamental boron compound. It has attracted wide attention for its electronic structure. Several of its derivatives are useful reagents.

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<span class="mw-page-title-main">Sodium borohydride</span> Chemical compound

Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, is an inorganic compound with the formula NaBH4. It is a white crystalline solid, usually encountered as an aqueous basic solution. Sodium borohydride is a reducing agent that finds application in papermaking and dye industries. It is also used as a reagent in organic synthesis.

<span class="mw-page-title-main">Nickel(II) chloride</span> Chemical compound

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<span class="mw-page-title-main">Germane</span> Chemical compound

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<span class="mw-page-title-main">Borohydride</span>

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Sodium metaborate is a chemical compound of sodium, boron, and oxygen with formula NaBO2. However, the metaborate ion is trimeric in the anhydrous solid, therefore a more correct formula is Na3B3O6 or (Na+)3[B3O6]3−. The formula can be written also as Na2O·B2O3 to highlight the relation to the main oxides of sodium and boron. The name is also applied to several hydrates whose formulas can be written NaBO2·nH2O for various values of n.

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Cadmium hydride is an inorganic compound with the chemical formula (CdH
2
)
n
. It is a solid, known only as a thermally unstable, insoluble white powder.

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<span class="mw-page-title-main">Organoberyllium chemistry</span> Organoberyllium Complex in Main Group Chemistry

Organoberyllium chemistry involves the synthesis and properties of organometallic compounds featuring the group 2 alkaline earth metal beryllium (Be). The area remains understudied, relative to the chemistry of other main-group elements, because although metallic beryllium is relatively unreactive, its dust causes berylliosis and compounds are toxic. Organoberyllium compounds are typically prepared by transmetallation or alkylation of beryllium chloride.

References

  1. 1 2 3 NIOSH Pocket Guide to Chemical Hazards. "#0054". National Institute for Occupational Safety and Health (NIOSH).
  2. 1 2 3 4 5 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 115–116. ISBN   978-0-08-037941-8.
  3. 1 2 Marynick, Dennis S.; Lipscomb, William N. (1 April 1972). "Crystal structure of beryllium borohydride". Inorg. Chem. 11 (4): 820–823. doi:10.1021/ic50110a033.