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Bis(dinitrogen)bis(1,2-bis(diphenylphosphino)ethane)molybdenum(0)

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Bis(dinitrogen)bis­(1,2-bis(diphenylphosphino)­ethane)molybdenum(0)
Identifiers
CAS Number
3D model (JSmol)
ChEBI
ChemSpider
Gmelin Reference 59731
PubChem CID
InChI
  • InChI=1S/2C26H24P2.Mo.2N2/c2*1-5-13-23(14-6-1)27(24-15-7-2-8-16-24)21-22-28(25-17-9-3-10-18-25)26-19-11-4-12-20-26;;2*1-2/h2*1-20H,21-22H2;;;Key: ZEYRIXZZLVGNMH-UHFFFAOYSA-N
SMILES
  • P(c1ccccc1)(c2ccccc2)CCP(c3ccccc3)c4ccccc4.P(c5ccccc5)(c6ccccc6)CCP(c7ccccc7)c8ccccc8.N#N.N#N.
Properties
Chemical formula C52H48MoN4P4
Molar mass 948.84
Appearance Yellow-orange crystals
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Infobox references
Chemical compound

trans-Bis(dinitrogen)bismolybdenum(0) is a coordination complex with the formula Mo(N2)2(dppe)2. It is a relatively air stable yellow-orange solid. It is notable as being the first discovered dinitrogen containing complex of molybdenum.

Structure

Mo(N2)2(dppe)2 is an octahedral complex with idealized D2h point group symmetry. The dinitrogen ligands are mutually trans across the metal center. The Mo-N bond has a length of 2.01 Å, and the N-N bond has a length of 1.10 Å. This length is close to the free nitrogen bond length, but coordination to the metal weakens the N-N bond making it susceptible to electrophilic attack.

Synthesis

The first synthetic route to Mo(N2)2(DPPE)2 involved a reduction of molybdenum(III) acetylacetonate with triethylaluminium in the presence of dppe and nitrogen.

A higher yielding synthesis involves a four-step process. In the first step, molybdenum(V) chloride is reduced by acetonitrile (CH3CN) to give . Acetonitrile is displaced by tetrahydrofuran (THF) to give . This Mo(IV) compound is reduced by tin powder to . The desired compound is formed in the presence of nitrogen gas, dppe ligand, and magnesium turnings as the reductant:

3 Mg + 2 MoCl3(THF)3 + 4 Ph2PCH2CH2PPh2 + 4 N2 → 2 trans- + 3 MgCl2 + 6 THF

Reactivity

The terminal nitrogen is susceptible to electrophilic attack, allowing for the fixation of nitrogen to ammonia in the presence of acid. In this way, Mo(N2)2(dppe)2 serves as a model for biological nitrogen fixation. Carbon-nitrogen bonds can also be formed with this complex through condensation reactions with ketones and aldehydes, and substitution reactions with acid chlorides. The terminal nitrogen can also be silylated.

See also

References

  1. ^ Hidai, Masanobu.; Mizobe, Yasushi. (1995). "Recent Advances in the Chemistry of Dinitrogen Complexes". Chemical Reviews. 95 (4): 1115. doi:10.1021/cr00036a008.
  2. Uchida, Tokiko; Uchida, Yasuzo; Hidai, Masanobu; Kodama, Teruyuki (1971). "The Crystal and Molecular Structure oftrans-Bis(dinitrogen)bis[1,2-bis(diphenylphosphino)ethane]molybdenum(0)". Bulletin of the Chemical Society of Japan. 44 (10): 2883. doi:10.1246/bcsj.44.2883.
  3. ^ Hidai, Masanobu; Mizobe, Yasushi (1993). "Chemical Transformations of Coordinated Dinitrogen in Molybdenum and Tungsten Phosphine Complexes". Molybdenum Enzymes, Cofactors, and Model Systems. ACS Symposium Series. Vol. 535. pp. 346. doi:10.1021/bk-1993-0535.ch022. ISBN 0-8412-2708-X.
  4. Jonathan R. Dilworth; Raymond L. Richards (1990). The Synthesis of Molybdenum and Tungsten Dinitrogen Complexes. Inorganic Syntheses. Vol. 28. pp. 33–45. doi:10.1002/9780470132593.ch7. ISBN 9780470132593.
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