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

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Bis(dinitrogen)bis­(1,2-bis(diphenylphosphino)­ethane)molybdenum(0)
Mo(dppe)2(n2)2revd2.png
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
59731
PubChem CID
  • 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
  • P(c1ccccc1)(c2ccccc2)CCP(c3ccccc3)c4ccccc4.P(c5ccccc5)(c6ccccc6)CCP(c7ccccc7)c8ccccc8.N#N.N#N.[Mo]
Properties
C52H48MoN4P4
Molar mass 948.84
AppearanceYellow-orange crystals [1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

trans-Bis(dinitrogen)bis[1,2-bis(diphenylphosphino)ethane]molybdenum(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. [1]

Contents

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. [2] 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. [3]

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. [4] In the first step, molybdenum(V) chloride is reduced by acetonitrile (CH3CN) to give [MoCl4(CH3CN)2]. Acetonitrile is displaced by tetrahydrofuran (THF) to give [MoCl4(THF)2]. This Mo(IV) compound is reduced by tin powder to [MoCl3(thf)3]. 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-[Mo(N2)2(Ph2PCH2CH2PPh2)2] + 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. [3]

See also

Related Research Articles

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1,2-Bis(diphenylphosphino)ethane (dppe) is an organophosphorus compound with the formula (Ph2PCH2)2 (Ph = phenyl). It is a commonly used bidentate ligand in coordination chemistry. It is a white solid that is soluble in organic solvents.

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

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<span class="mw-page-title-main">Dihydrogen complex</span> Containing intact H2 as a ligand

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<span class="mw-page-title-main">1,1'-Bis(diphenylphosphino)ferrocene</span> Chemical compound

1,1-Bis(diphenylphosphino)ferrocene, commonly abbreviated dppf, is an organophosphorus compound commonly used as a ligand in homogeneous catalysis. It contains a ferrocene moiety in its backbone, and is related to other bridged diphosphines such as 1,2-bis(diphenylphosphino)ethane (dppe).

<span class="mw-page-title-main">Transition metal dinitrogen complex</span> Coordination compounds with N2

Transition metal dinitrogen complexes are coordination compounds that contain transition metals as ion centers the dinitrogen molecules (N2) as ligands.

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

Diphosphines, sometimes called bisphosphanes, are organophosphorus compounds most commonly used as bidentate phosphine ligands in inorganic and organometallic chemistry. They are identified by the presence of two phosphino groups linked by a backbone, and are usually chelating. A wide variety of diphosphines have been synthesized with different linkers and R-groups. Alteration of the linker and R-groups alters the electronic and steric properties of the ligands which can result in different coordination geometries and catalytic behavior in homogeneous catalysts.

<span class="mw-page-title-main">Bis(diphenylphosphino)methane</span> Chemical compound

1,1-Bis(diphenylphosphino)methane (dppm), is an organophosphorus compound with the formula CH2(PPh2)2. Dppm, a white, crystalline powder, is used in inorganic and organometallic chemistry as a ligand. It is more specifically a chelating ligand because it is a ligand that can bond to metals with two phosphorus donor atoms. The natural bite angle is 73°.

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<span class="mw-page-title-main">1,2-Bis(dimethylphosphino)ethane</span> Chemical compound

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<span class="mw-page-title-main">Chlorobis(dppe)iron hydride</span> Chemical compound

Chlorobis(dppe)iron hydride is a coordination complex with the formula HFeCl(dppe)2, where dppe is the bidentate ligand 1,2-bis(diphenylphosphino)ethane. It is a red-violet solid. The compound has attracted much attention as a precursor to dihydrogen complexes.

<span class="mw-page-title-main">Tris(trimethylsilyl)amine</span> Chemical compound

Tris(trimethylsilyl)amine is the simplest tris(trialkylsilyl)amine which are having the general formula (R3Si)3N, in which all three hydrogen atoms of the ammonia are replaced by trimethylsilyl groups (-Si(CH3)3). Tris(trimethylsilyl)amine has been for years in the center of scientific interest as a stable intermediate in chemical nitrogen fixation (i. e. the conversion of atmospheric nitrogen N2 into organic substrates under normal conditions).

<span class="mw-page-title-main">Transition metal nitrile complexes</span> Class of coordination compounds containing nitrile ligands (coordinating via N)

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<span class="mw-page-title-main">1,4-Bis(diphenylphosphino)butane</span> Chemical compound

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<span class="mw-page-title-main">Abiological nitrogen fixation using homogeneous catalysts</span> Chemical process that converts nitrogen to ammonia

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<span class="mw-page-title-main">Transition metal ether complex</span>

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References

  1. 1 2 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. 1 2 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.