Molybdenum hexacarbonyl: Difference between revisions - Wikipedia

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{{chemboxChembox

|Verifiedfields = changed

| Name = Molybdenum hexacarbonyl

|Watchedfields = changed

| ImageFile = Molybdenum-hexacarbonyl-2D.png

|verifiedrevid = 268875245

| IUPACName = hexacarbonylmolybdenum(0)

|ImageFileL1 = Molybdenum-hexacarbonyl-2D.png

| Section1 = {{Chembox Identifiers

|ImageFileL1_Ref = {{chemboximage|correct|??}}

| CASNo = 13939-06-5

|ImageSizeL1 = 121

| CASNo_Ref = {{cascite}}

|ImageNameL1 = Stereo, skeletal formula of molybdenum hexacarbonyl

}}

|ImageFileR1 = Molybdenum-hexacarbonyl-from-xtal-3D-balls.png

| Section2 = {{Chembox Properties

|ImageFileR1_Ref = {{chemboximage|correct|??}}

| Formula = C₆O₆Mo

|ImageSizeR1 = 121

| MolarMass = 264.00 g/mol

|ImageNameR1 = Ball and stick model of molybdenum hexacarbonyl

| Density = 1.96 g/cm³ solid

|ImageFile2 = Mocarbonyl.JPG

| Solubility = insoluble

|ImageFile2_Ref = {{chemboximage|correct|??}}

| MeltingPt = 150 °C

|ImageSize2 = 244

| BoilingPt = sublimes

|ImageName2 = Sample of molybdenum hexacarbonyl

}}

|IUPACName = Hexacarbonylmolybdenum(0)

| Section3 = {{Chembox Structure

|SystematicName = Hexacarbonylmolybdenum<ref>{{Cite web | title = Hexacarbonylmolybdenum (CHEBI:30508) | url = https://www.ebi.ac.uk/chebi/searchId.do?chebiId=30508 | work = Chemical Entities of Biological Interest (ChEBI) | location = UK | publisher = European Bioinformatics Institute }}</ref>

| Coordination = octahedral

|Section1={{Chembox Identifiers

| CrystalStruct =

|CASNo = 13939-06-5

| Dipole = 0 [[Debye|D]]

|CASNo_Ref = {{cascite|correct|CAS}}

}}

|PubChem = 98885

| Section7 = {{Chembox Hazards

|ChemSpiderID = 21428397

| ExternalMSDS = [http://ptcl.chem.ox.ac.uk/MSDS/HE/hexacarbonylmolybdenum.html External MSDS]

|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| EUIndex = Not listed

|EINECS = 237-713-3

| MainHazards = flammable, CO source

|UNNumber = 3466

| FlashPt =

|MeSHName = Hexacarbonylmolybdenum

| RPhrases =

|ChEBI_Ref = {{ebicite|correct|EBI}}

| SPhrases =

|ChEBI = 30508

}}

|Gmelin = 3798, 562210

| Section8 = {{Chembox Related

|SMILES = O=C=[Mo](=C=O)(=C=O)(=C=O)(=C=O)=C=O

| OtherCations = [[Chromium hexacarbonyl]]<br/>[[Tungsten hexacarbonyl]]

|StdInChI = 1S/6CO.Mo/c6*1-2;

}}

|StdInChI_Ref = {{stdinchicite|changed|chemspider}}

|StdInChIKey = KMKBZNSIJQWHJA-UHFFFAOYSA-N

|StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}

}}

|Section2={{Chembox Properties

|C=6 | Mo=1 | O=6

|Appearance = Vivid, white, translucent crystals

|Density = 1.96 g cm⁻³

|MeltingPtC = 150

|BoilingPtC = 156

|Solubility = insoluble

|SolubleOther = slightly soluble in [[Tetrahydrofuran|THF]], [[diglyme]], [[acetonitrile]]<ref>{{cite book |last1= Faller|first1= John W.|last2= Brummond|first2= Kay M.|last3=Mitasev |first3= Branko|date= 15 September 2006|title= Encyclopedia of Reagents for Organic Synthesis|chapter=Hexacarbonylmolybdenum |url= https://onlinelibrary.wiley.com/doi/10.1002/047084289X.rh004.pub2|location= |publisher= [[Wiley (publisher)|Wiley]]|page= |doi=10.1002/047084289X |hdl= 10261/236866|isbn=9780470842898}}</ref>

}}

|Section3={{Chembox Structure

|CrystalStruct = Orthogonal

|Coordination = Octahedral

|Dipole = 0 D

}}

|Section4={{Chembox Thermochemistry

|DeltaHf = −989.1 kJ mol⁻¹

|DeltaHc = −2123.4 kJ mol⁻¹

}}

|Section5={{Chembox Hazards

|ExternalSDS = [https://ereztech.com/wp-content/uploads/chemical_sds/SDS-MO9065.pdf External MSDS]

|GHSPictograms = {{GHS06}}

|GHSSignalWord = Danger

|HPhrases = {{H-phrases|300|310|315|319|330|413}}

|PPhrases = {{P-phrases|261|271|280|304+340+311|405|501}}

|NFPA-H = 4

|NFPA-F = 1

|NFPA-R = 0

}}

|Section6={{Chembox Related

|OtherCompounds = [[Chromium hexacarbonyl]]<br />

<br />[[Tungsten hexacarbonyl]]<br />[[Seaborgium hexacarbonyl]]<ref name="carbonyl">{{Cite journal | doi = 10.1126/science.1255720| pmid = 25237098| title = Synthesis and detection of a seaborgium carbonyl complex| journal = Science| volume = 345| issue = 6203| pages = 1491–3| year = 2014| last1 = Even | first1 = J.| last2 = Yakushev | first2 = A.| last3 = Dullmann | first3 = C. E.| last4 = Haba | first4 = H.| last5 = Asai | first5 = M.| last6 = Sato | first6 = T. K.| last7 = Brand | first7 = H.| last8 = Di Nitto | first8 = A.| last9 = Eichler | first9 = R.| last10 = Fan | first10 = F. L.| last11 = Hartmann | first11 = W.| last12 = Huang | first12 = M.| last13 = Jager | first13 = E.| last14 = Kaji | first14 = D.| last15 = Kanaya | first15 = J.| last16 = Kaneya | first16 = Y.| last17 = Khuyagbaatar | first17 = J.| last18 = Kindler | first18 = B.| last19 = Kratz | first19 = J. V.| last20 = Krier | first20 = J.| last21 = Kudou | first21 = Y.| last22 = Kurz | first22 = N.| last23 = Lommel | first23 = B.| last24 = Miyashita | first24 = S.| last25 = Morimoto | first25 = K.| last26 = Morita | first26 = K.| last27 = Murakami | first27 = M.| last28 = Nagame | first28 = Y.| last29 = Nitsche | first29 = H.| last30 = Ooe | first30 = K.| display-authors = 29| bibcode = 2014Sci...345.1491E| s2cid = 206558746}} {{subscription required}}</ref>

}}

}}

'''Molybdenum hexacarbonyl''' (also called '''molybdenum carbonyl''') is the [[chemical compound]] with the formula Mo(CO)₆. This colorless solid, like its [[chromium hexacarbonyl|chromium]] and [[tungsten hexacarbonyl|tungsten]] analogues, is noteworthy as a volatile, air-stable derivative of a metal in its zero oxidation state.

'''Molybdenum hexacarbonyl''' (also called '''molybdenum carbonyl''') is the [[chemical compound]] with the formula Mo(CO)₆. This colorless solid, like its [[chromium hexacarbonyl|chromium]], [[tungsten hexacarbonyl|tungsten]], and [[seaborgium hexacarbonyl|seaborgium]] analogues, is noteworthy as a volatile, air-stable derivative of a metal in its zero oxidation state.

==Preparation, properties, and structure==

Mo(CO)₆ is prepared by the [[Redox|reduction]] of molybdenum chlorides or oxides under a pressure of [[carbon monoxide]], although it would be unusual to prepare this inexpensive compound in the laboratory. The compound is somewhat air-stable and sparingly soluble in nonpolar organic solvents.

==Structure and properties==

Mo(CO)₆ adopts an [[octahedral geometry]] consisting of six rod-like CO [[ligand]]s radiating from the central Mo atom. A recurring minor debate in some chemical circles concerns the definition of an "[[organometallic]]" compound. Usually, organometallic indicates the presence of a metal directly bonded via a M-C bond to an organic fragment, which must in turn a C-H bond. By this strict definition, Mo(CO)₆ is not organometallic.

Mo(CO)₆ adopts an [[octahedral geometry]] consisting of six rod-like CO [[ligand]]s radiating from the central Mo atom. A recurring minor debate in some chemical circles concerns the definition of an "[[organometallic]]" compound. Usually, organometallic indicates the presence of a metal directly bonded via a M–C bond to an organic fragment, which must in turn have a C–H bond.

Like many [[metal carbonyl]]s, Mo(CO)₆ is generally prepared by "reductive carbonylation", which involves reduction of a metal halide with under an atmosphere of [[carbon monoxide]]. As described in a 2023 survey of methods "most cost-effective routes for the synthesis of group 6 hexacarbonyls are based on the reduction of the metal chlorides (CrCl₃, MoCl₅ or WCl₆) with magnesium, zinc or aluminium powders... under CO pressures".<ref>{{cite journal |doi=10.1016/j.ccr.2022.214983|title=Group 6 Carbonyl Complexes of N,O,P-Ligands as Precursors of High-Valent Metal-Oxo Catalysts for Olefin Epoxidation |year=2023 |last1=Bruno |first1=Sofia M. |last2=Valente |first2=Anabela A. |last3=Gonçalves |first3=Isabel S. |last4=Pillinger |first4=Martyn |journal=Coordination Chemistry Reviews |volume=478 |page=214983 |s2cid=255329673 |doi-access=free |hdl=10773/40120 |hdl-access=free }}</ref>

==Applications in inorganic and organometallic synthesis==

Mo(CO)₆ is a popular reagent in organometallic synthesis<ref>Faller, J. W. "Hexacarbonylmolybdenum" in [[Encyclopedia of Reagents for Organic Synthesis]] (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. {{doi|10.1002/047084289}}.</ref> because one or more CO ligands can be displaced by other donor ligands.<ref>http://www.chm.bris.ac.uk/teaching-labs/inorganic2ndyear/2004-2005labmanual/Experiment3.pdf</ref> For example, Mo(CO)₆ reacts with [[2,2'-bipyridine]] to afford Mo(CO)₄(bipy). UV-photolysis of a [[THF]] solution of Mo(CO)₆ gives Mo(CO)₅(THF). Many metal carbonyls are similarly photo-activatable.

==Occurrence==

Mo(CO)₆ has been detected in [[landfill]]s and [[sewage]] plants, the reducing, anaerobic environment being conducive to formation of Mo(CO)₆.<ref>{{cite journal | last= Feldmann |first=J. | title = Determination of Ni(CO)₄, Fe(CO)₅, Mo(CO)₆, and W(CO)₆ in Sewage Gas by Using Cryotrapping Gas Chromatography Inductively Coupled Plasma Mass Spectrometry | journal = [[Journal of Environmental Monitoring]] | year = 1999 | volume = 1 | issue = 1 | pages = 33–37 | doi = 10.1039/a807277i | pmid=11529076}}</ref>

==Inorganic and organometallic research==

Molybdenum hexacarbonyl is a popular reagent in academic research.<ref>{{cite encyclopedia | last1= Faller |first1=J. W. |last2=Brummond |first2=K. M. |last3=Mitasev |first3=B. | chapter = Hexacarbonylmolybdenum | encyclopedia = [[Encyclopedia of Reagents for Organic Synthesis]] | editor-first = L. |editor-last=Paquette | year = 2006 | publisher = J. Wiley & Sons | location = New York | doi = 10.1002/047084289X.rh004.pub2 |isbn=0471936235}}</ref>

One or more CO ligands can be displaced by other ligands.<ref>{{cite web |url=http://www.chm.bris.ac.uk/teaching-labs/inorganic2ndyear/2004-2005labmanual/Experiment3.pdf |title=THE SYNTHESIS & SPECTROSCOPIC CHARACTERISATION OF METAL CARBONYL COMPLEXES |website=www.chm.bris.ac.uk |archive-url=https://web.archive.org/web/20080309162142/http://www.chm.bris.ac.uk/teaching-labs/inorganic2ndyear/2004-2005labmanual/Experiment3.pdf |archive-date=March 9, 2008}}</ref> Mo(CO)₆, [Mo(CO)₃(MeCN)₃], and related derivatives are employed as [[catalyst]]s in [[organic synthesis]] for example, [[alkyne metathesis]] and the [[Pauson–Khand reaction]].

Mo(CO)₆ reacts with [[2,2′-bipyridine]] to afford Mo(CO)₄(bipy). UV-photolysis of a [[THF]] solution of Mo(CO)₆ gives Mo(CO)₅(THF).

===[Mo(CO)₄(piperidine)₂]===

The thermal reaction of Mo(CO)₆ with [[piperidine]] affords Mo(CO)₄(piperidine)₂. The two piperidine ligands in this yellow-colored compound are labile, which allows other ligands to be introduced under mild conditions. For instance, the reaction of [Mo(CO)₄(piperidine)₂] with [[triphenyl phosphine]] in [[boiling]] [[dichloromethane]] (b.p. ca. 40 &nbsp;°C) gives [[Cis-trans isomerism|''cis'']]-[Mo(CO)₄(PPh₃)₂],. thisThis ''cis-'' complex [[isomer]]izes in [[toluene]] to [[trans isomer|''trans'']]-[Mo(CO)₄(PPh₃)₂].<ref>{{cite journal | last1 = Darensbourg | first1 = D. J. | last2 = Kump | first2 = R. L. | title = A Convenient Synthesis of ''cis''-Mo(CO)₄L₂ Derivatives (L = Group 5a Ligand) and a Qualitative Study of Their Thermal Reactivity toward Ligand Dissociation |journal = [[Inorganic Chemistry (journal)|Inorg. Chem.]] | year = 1978 | volume = 17 | issue = 9 | pages = 2680–2682 | doi = 10.1021/ic50187a062 }}</ref>

===[Mo(CO)₃(MeCN)₃]===

Upon heating in a solution of [[acetonitrile]], Mo(CO)₆ convertsalso can be converted to its tris(acetonitrile) derivative. The resulting compound serves as a source of "Mo(CO)₃". For instance treatment with allyl chloride gives [MoCl(allyl)(CO)₂(MeCN)₂], whereas treatment with [[Scorpionate ligand|KTp]] and Na[[cyclopentadienylsodium cyclopentadienide]] gives [MoTp(CO)₃]^-− and [MoCp(CO)₃]^-− anions, respectively. These anions can be reactedreact with electrophiles to form a wide rangevariety of productselectrophiles.<ref>{{cite book | last1= Elschenbroich, |first1=C.; |last2=Salzer, |first2=A. ”Organometallics| title = Organometallics: A Concise Introduction”Introduction | edition = (2nd Ed)| year = (1992) | publisher = Wiley-VCH: | location = Weinheim. ISBN| isbn = 3-527-28165-7 }}</ref> A related source of Mo(CO)₃ is [[cycloheptatrienemolybdenum tricarbonyl]].

===Source of Mo atoms===

==Applications in organic synthesis==

Molybdenum hexacarbonyl is widely used in [[electron beam-induced deposition]] technique - it is easily vaporized and decomposed by the electron beam providing a convenient source of molybdenum atoms.<ref name="r1">{{ cite journal | last1 = Randolph | first1 = S. J. | last2 = Fowlkes | first2 = J. D. | last3 = Rack | first3 = P. D. | title = Focused, Nanoscale Electron-Beam-Induced Deposition and Etching | journal = Critical Reviews of Solid State and Materials Sciences | volume = 31 | year = 2006 | issue = 3 | pages = 55–89 | doi = 10.1080/10408430600930438 | bibcode = 2006CRSSM..31...55R | s2cid = 93769658 }}</ref>

Mo(CO)₆, [Mo(CO)₃(MeCN)₃], and related derivatives are employed as [[catalyst]]s in [[organic synthesis]]. For example, these catalysts can be used for [[alkyne metathesis]] and the [[Pauson–Khand reaction]].

==Occurrence in [[nature]] ==

Mo(CO)₆ has been detected in [[landfill]]s and [[sewage]] plants, the reducing, anaerobic environment being conducive to formation of Mo(CO)₆.<ref>Feldmann, J. “Determination of Ni(CO)₄, Fe(CO)₅, Mo(CO)₆, and W(CO)₆ in sewage gas by using cryotrapping gas chromatography inductively coupled plasma mass spectrometry” Journal of Environmental Monitoring, 1999, 1, page 33-37. DOI: 10.1039/a807277i.</ref>

==Safety and handling==

Like all metal carbonyls, Mo(CO)₆ is a dangerous source of volatile metal as well as [[Carbon monoxide|CO. It diffuses readily into plastic stoppers]].

==References==

{{reflist}}

==OtherFurther reading==

* {{cite journal | last= Marradi |first=M. | title = Synlett Spotlight 119: Molybdenum Hexacarbonyl <nowiki>[</nowiki>Mo(CO)₆<nowiki>]</nowiki> | journal = [[Synlett]] | year = 2005 | volume = 2005 | issue = 7 | pages = 1195–1196 | doi = 10.1055/s-2005-865206 | url = https://www.thieme-connect.de/ejournals/pdf/synlett/doi/10.1055/s-2005-865206.pdf | doi-access = free}}

* Marradi, "Synlett spotlight 119", SYNLETT 2005, No. 7, pp 1195-1196 {{doi|10.1055/s-2005-865206}}

* {{cite journal | last1= Feldmann |first1=J. Feldmann,|last2=Cullen |first2=W. R. Cullen,| title = Occurrence of volatileVolatile transitionTransition metalMetal compoundsCompounds in landfillLandfill gasGas: synthesisSynthesis of molybdenumMolybdenum and tungstenTungsten carbonylsCarbonyls in the environment,Environment | journal = ''Environ. Sci. Technol''. | year = 1997, '''| volume = 31''', 2125-2129| issue = 7 | pages = 2125–2129 | doi = 10.1021/es960952y |bibcode=1997EnST...31.2125F}}

* {{cite journal | last1= Feldmann |first1=J. |last2=Grümping |first2=R. |last3=Hirner |first3=A. V. | title = Determination of Volatile Metal and Metalloid Compounds in Gases from Domestic Waste Deposits with GC/ICP-MS | journal = Fresenius' J. Anal. Chem. | year = 1994 | volume = 350 | issue = 4–5 | pages = 228–234 | doi = 10.1007/BF00322474 |s2cid=95405500 }}

* J. Feldmann, Determination of Ni(CO)4, Fe(CO)5, Mo(CO)6 and W(CO)6 in sewage gas by using cryotrapping gas chromatography inductively coupled plasma mass spectrometry, ''J. Environm. Mon.'', 1999, '''1''', 33-37.

* J. Feldmann, R. Grümping, A.V. Hirner, Determination of volatile metal and metalloid compounds in gases from domestic waste deposits with GC-ICP-MS, ''Fresenius J. Anal. Chem.'', 1994, '''350''', 228-235.

{{Molybdenum compounds}}

[[Category:Molybdenum(0) compounds]]

[[Category:Carbonyl complexes]]

[[Category:Inorganic carbonOrganomolybdenum compounds]]

[[Category:Octahedral compounds]]