:Dimanganese decacarbonyl

Many procedures have been reported for the synthesis of Mn₂(CO)₁₀ since 1954. Some of these methods serendipitously produce Mn₂(CO)₁₀.

The carbonylation route involves treatment of Mn(II) salt under high pressure of CO and in the presence of a reductant. This is the method reported in 1954 by Brimm, Lynch, and Sesny, albeit in yields of ~1%. They used manganese(II) iodide with magnesium(0) as the reductant under 3000 psi (~200 atm) of carbon monoxide (CO):

:{{chem2|2 MnI2 + 2 Mg + 10 CO -> Mn2(CO)10 + 2 MgI2}}

A more efficient preparation was developed in 1958 and entails reduction of anhydrous manganese(II) chloride with sodium benzophenone ketyl radical under similarly high pressures (200 atm) of CO.{{Cite journal |last1=Closson |first1=Rex D. |last2=Buzbee |first2=Lloyd R. |last3=Ecke |first3=George G. |date=December 1958 |title=A New Metal Carbonyl Synthesis 1 |url=https://pubs.acs.org/doi/abs/10.1021/ja01556a005 |journal=Journal of the American Chemical Society |language=en |volume=80 |issue=23 |pages=6167–6170 |doi=10.1021/ja01556a005 |bibcode=1958JAChS..80.6167C |issn=0002-7863|url-access=subscription }} The yield is ~32%.

File:Mn2(CO)10CarbonylationSynth.png

An ambient pressure synthesis of Mn₂(CO)₁₀ was reported from the commercially available and inexpensive methylcyclopentadienyl manganese tricarbonyl (MMT) and sodium(0) as the reductant.{{Cite journal |last1=King |first1=R. B. |last2=Stokes |first2=J. C. |last3=Korenowski |first3=T. F. |date=1968-01-01 |title=A Convenient Synthesis of Dimanganese Decarbonyl from Inexpensive Starting Materials at Atmospheric Pressure |url=https://dx.doi.org/10.1016/0022-328X%2868%2980099-3 |journal=Journal of Organometallic Chemistry |language=en |volume=11 |pages=641–643 |doi=10.1016/0022-328X(68)80099-3 |issn=0022-328X|url-access=subscription }} The balanced equation being:

:{{chem2|2 Mn(\h{1}(5)\s(CH3C5H4)(CO)3 + 2 Na + 4 CO -> Mn2(CO)10 + 2NaCH3C5H4}}

The efficiency of the method ranged from 16 to 20% yield, lower than what was previously reported, however, it could be performed more conveniently and on mole scale.

Pentacarbonylhydridomanganese(-I) Mn source, oxidized by Se(PF₂)₂:{{Cite journal |last1=Arnold |first1=David E. J. |last2=Cromie |first2=Ernest R. |last3=Rankin |first3=David W. H. |date=1977 |title=Preparation and chemical and spectroscopic properties of bis(difluorophosphino) selenide |url=http://xlink.rsc.org/?DOI=dt9770001999 |journal=Journal of the Chemical Society, Dalton Transactions |language=en |issue=20 |pages=1999–2004 |doi=10.1039/dt9770001999 |issn=0300-9246|url-access=subscription }} 2 Mn(CO)5(H) + Se(PF2)2 -> Mn2(CO)10 + PF2H + Se=PF2H Other terminal oxidants achieve the same effect,{{Cite journal |last1=Sweany |first1=Ray |last2=Butler |first2=Steven C. |last3=Halpern |first3=Jack |date=1981-06-23 |title=The hydrogenation of 9,10-dimethylanthracene by hydridopentacarbonylmanganese(I). Evidence for a free-radical mechanism |url=https://www.sciencedirect.com/science/article/pii/S0022328X0082954X |journal=Journal of Organometallic Chemistry |language=en |volume=213 |issue=2 |pages=487–492 |doi=10.1016/S0022-328X(00)82954-X |issn=0022-328X|url-access=subscription }}{{Cite journal |last1=Booth |first1=Brian L. |last2=Haszeldine |first2=Robert N. |last3=Holmes |first3=Robert G. G. |date=1982 |title=Reactions involving transition metals. Part 16. Rhodium, iridium, platinum, and gold complexes containing the bis(trifluoromethyl)amino-oxy-ligand |url=http://xlink.rsc.org/?DOI=dt9820000523 |journal=Journal of the Chemical Society, Dalton Transactions |language=en |issue=3 |pages=523–529 |doi=10.1039/dt9820000523 |issn=0300-9246|url-access=subscription }}{{Cite journal |last1=Tam |first1=Wilson |last2=Marsi |first2=Marianne |last3=Gladysz |first3=J. A. |date=May 1983 |title=Bimetallic anionic formyl complexes: synthesis and properties |url=https://pubs.acs.org/doi/abs/10.1021/ic00152a001 |journal=Inorganic Chemistry |language=en |volume=22 |issue=10 |pages=1413–1421 |doi=10.1021/ic00152a001 |issn=0020-1669|url-access=subscription }} and stable pentacarbonylmanganate (Mn(CO){{su|b=5|p=−}}) salts can substitute for the hydride.{{Cite journal |last1=DuBois |first1=Donn A. |last2=Duesler |first2=Eileen N. |last3=Paine |first3=Robert T. |date=January 1985 |title=Formation and x-ray crystal structure determination of an unusual phosphorus-phosphorus coupled bicyclodiphosphazane complex |url=https://pubs.acs.org/doi/abs/10.1021/ic00195a003 |journal=Inorganic Chemistry |language=en |volume=24 |issue=1 |pages=3–5 |doi=10.1021/ic00195a003 |issn=0020-1669|url-access=subscription }}{{Cite journal |last1=Ozin |first1=Geoffrey A. |last2=Coleson |first2=Kraig M. |last3=Huber |first3=Helmut X. |date=March 1983 |title=Reactions of solvated metal atoms with organometallic complexes in solution. A metal atom microsolution spectroscopic and synthetic study of the reaction pathways available to singly metal-metal bonded organometallic complexes and their organometallic anions |url=https://pubs.acs.org/doi/abs/10.1021/om00075a011 |journal=Organometallics |language=en |volume=2 |issue=3 |pages=415–420 |doi=10.1021/om00075a011 |issn=0276-7333|url-access=subscription }}{{Cite journal |last1=Müller |first1=Manfred |last2=Vahrenkamp |first2=Heinrich |date=June 1983 |title=Cluster-Konstruktion: Schrittweiser Aufbau von μ 3 -RP-Trimetall-Clustern über P–Hal-Verbindungen |url=https://onlinelibrary.wiley.com/doi/10.1002/cber.19831160621 |journal=Chemische Berichte |language=en |volume=116 |issue=6 |pages=2322–2336 |doi=10.1002/cber.19831160621 |issn=0009-2940|url-access=subscription }} Thus for example triphenylcyclopropenium tetrafluoroborate reacts with sodium pentacarbonyl manganate to produce the dimer of each:{{Cite journal |last1=Hughes |first1=Russell P. |last2=Lambert |first2=James M. J. |last3=Reisch |first3=John W. |last4=Smith |first4=Wayne L. |date=October 1982 |title=Reinvestigations of some reactions of metal carbonyl anions with cyclopropenium cations. Conversion of .eta.3-cyclopropenyl to .eta.3-cyclobutenonyl ligands |url=https://pubs.acs.org/doi/abs/10.1021/om00070a027 |journal=Organometallics |language=en |volume=1 |issue=10 |pages=1403–1405 |doi=10.1021/om00070a027 |issn=0276-7333|url-access=subscription }}

File:Mn2(CO)10OxidationSynth.png

Similar methods exist for Mn(CO)₅X compounds where X = Cl, Br, or I; and, more rarely, for Mn(CO){{su|b=6|p=+}} bound with a weakly coordinating anion.{{Cite journal |last1=Kolthammer |first1=Brian W. S. |last2=Legzdins |first2=Peter |date=1978 |title=Organometallic nitrosyl chemistry. Part 3. Some aspects of the chemistry of bis[(η-cyclopentadienyl)dinitrosylchromium] |url=http://xlink.rsc.org/?DOI=DT9780000031 |journal=J. Chem. Soc., Dalton Trans. |language=en |issue=1 |pages=31–35 |doi=10.1039/DT9780000031 |issn=0300-9246|url-access=subscription }}{{Cite journal |last1=Manning |first1=Mark C. |last2=Trogler |first2=William C. |date=1981-01-01 |title=Reduction of metal carbonyls with alkali metal carbides |url=https://www.sciencedirect.com/science/article/pii/S0020169300837524 |journal=Inorganica Chimica Acta |language=en |volume=50 |pages=247–250 |doi=10.1016/S0020-1693(00)83752-4 |issn=0020-1693|url-access=subscription }}{{Cite journal |last1=Gibson |first1=Dorothy H. |last2=Hsu |first2=Wen-Liang |date=1982-01-01 |title=Reactions of manganese carbonyls with quaternary ammonium halides |url=https://www.sciencedirect.com/science/article/pii/S0020169300873144 |journal=Inorganica Chimica Acta |language=en |volume=59 |pages=93–99 |doi=10.1016/S0020-1693(00)87314-4 |issn=0020-1693|url-access=subscription }}{{Cite journal |last1=Kuchynka |first1=D. J. |last2=Amatore |first2=C. |last3=Kochi |first3=J. K. |date=November 1986 |title=Manganese(0) radicals and the reduction of cationic carbonyl complexes: selectivity in the ligand dissociation from 19-electron species |url=https://pubs.acs.org/doi/abs/10.1021/ic00243a009 |journal=Inorganic Chemistry |language=en |volume=25 |issue=23 |pages=4087–4097 |doi=10.1021/ic00243a009 |issn=0020-1669|url-access=subscription }}{{Cite journal |last1=Geier |first1=Jens |last2=Willner |first2=Helge |last3=Lehmann |first3=Christian W. |last4=Aubke |first4=Friedhelm |date=2007-08-01 |title=Formation of Hexacarbonylmanganese(I) Salts, [Mn(CO) 6 ] + X - , in Anhydrous HF |url=https://pubs.acs.org/doi/10.1021/ic700798z |journal=Inorganic Chemistry |language=en |volume=46 |issue=17 |pages=7210–7214 |doi=10.1021/ic700798z |pmid=17616186 |issn=0020-1669|url-access=subscription }}{{Cite journal |last1=Manning |first1=Peter J. |last2=Peterson |first2=Louis K. |last3=Wada |first3=Fumio |last4=Dhami |first4=Randi S. |date=1986-04-01 |title=Synthesis and reactions of [M(CO)4(Ph2PSiMe3)X] complexes (M = Mn, Re; X = Halogen) |url=https://www.sciencedirect.com/science/article/pii/S0020169300845818 |journal=Inorganica Chimica Acta |language=en |volume=114 |issue=1 |pages=15–20 |doi=10.1016/S0020-1693(00)84581-8 |issn=0020-1693|url-access=subscription }}

One additional interesting synthesis of Mn₂(CO)₁₀ occurs by combination of a hexacarbonylmanganese(I) tetrafluoroborate salt with a sodium pentacarbonyl manganate salt. In this instance, manganese is both the oxidant and reductant, producing two formal Mn(0) atoms:{{Cite journal |last1=Lee |first1=K. Y. |last2=Kuchynka |first2=D. J. |last3=Kochi |first3=J. K. |date=1987-09-01 |title=Formation of metal-metal bonds by ion-pair annihilation. Dimanganese carbonyls from manganate(I-) anions and manganese(I) cations |url=https://pubs.acs.org/doi/abs/10.1021/om00152a010 |journal=Organometallics |language=en |volume=6 |issue=9 |pages=1886–1897 |doi=10.1021/om00152a010 |issn=0276-7333|url-access=subscription }}

[Mn(CO)6](BF4) + Na[Mn(CO)5] -> Mn2(CO)10 + Na[BF4] + CO

This hypothesized structure was confirmed explicitly through x-ray diffraction studies, first in two dimensions in 1957,{{Cite journal |last1=Dahl |first1=Lawrence F. |last2=Ishishi |first2=Etsuro |last3=Rundle |first3=R. E. |date=2004-10-06 |title=Polynuclear Metal Carbonyls. I. Structures of Mn2(CO)10 and Re2(CO)10 |url=https://aip.scitation.org/doi/abs/10.1063/1.1743615 |journal=The Journal of Chemical Physics |language=en |volume=26 |issue=6 |pages=1750 |doi=10.1063/1.1743615 |issn=0021-9606|url-access=subscription }} followed by its single crystal three-dimensional analysis in 1963.{{Cite journal |last1=Dahl |first1=L. F. |last2=Rundle |first2=R. E. |date=1963-05-10 |title=The crystal structure of dimanganese decacarbonyl Mn2(CO)10 |url=https://scripts.iucr.org/cgi-bin/paper?a03815 |journal=Acta Crystallographica |language=en |volume=16 |issue=5 |pages=419–426 |doi=10.1107/S0365110X63001080 |bibcode=1963AcCry..16..419D |issn=0365-110X|url-access=subscription }} The crystal structure of Mn₂(CO)₁₀ was redetermined at high precision at room temperature in 1981 and bond lengths mentioned herein refer to results from that study.{{Cite journal |last1=Churchill |first1=Melvyn Rowen |last2=Amoh |first2=Kwame N. |last3=Wasserman |first3=Harvey J. |date=May 1981 |title=Redetermination of the crystal structure of dimanganese decacarbonyl and determination of the crystal structure of dirhenium decacarbonyl. Revised values for the manganese-manganese and rhenium-rhenium bond lengths in dimanganese decacarbonyl and dirhenium decacarbonyl |url=https://pubs.acs.org/doi/abs/10.1021/ic50219a056 |journal=Inorganic Chemistry |language=en |volume=20 |issue=5 |pages=1609–1611 |doi=10.1021/ic50219a056 |issn=0020-1669|url-access=subscription }} Mn₂(CO)₁₀ has no bridging CO ligands: it can be described as containing two axially-linked (CO)₅Mn- subunits. These Mn subunits are spaced at a distance of 290.38(6) pm, a bonding distance that is longer than that predicted.{{Cite journal |last=Pyykkö |first=Pekka |date=2015-03-19 |title=Additive Covalent Radii for Single-, Double-, and Triple-Bonded Molecules and Tetrahedrally Bonded Crystals: A Summary |url=https://pubs.acs.org/doi/10.1021/jp5065819 |journal=The Journal of Physical Chemistry A |language=en |volume=119 |issue=11 |pages=2326–2337 |doi=10.1021/jp5065819 |pmid=25162610 |bibcode=2015JPCA..119.2326P |issn=1089-5639|url-access=subscription }} Two CO ligands are linked to each Mn atom that is coaxial with the Mn-Mn bond and four “equatorial” carbonyls bonded to each Mn atom that are nearly perpendicular to the Mn-Mn bond (Mn’-Mn-CO(equatorial) angles range from 84.61(7) to 89.16(7) degrees). The axial carbonyl distance of (181.1 pm) is 4.5 pm shorter than the average equatorial manganese-carbonyl distance of 185.6 pm. In the stable rotamer, the two Mn(CO)₅ subunits are staggered. Thus, the overall molecule has approximate point group D_4d symmetry, which is an uncommon symmetry shared with S₂F₁₀. The Mn₂(CO)₁₀ molecule is isomorphous with the other group 7 binary metal carbonyls Tc₂(CO)₁₀ and Re₂(CO)₁₀.

File:Mn2(CO)10Geometry.png

Initial fundamental experimental and theoretical studies on the electronic structure of Mn₂(CO)₁₀ were performed used a mixture of photoelectron spectroscopy, infrared spectroscopy, and an iterative extended-Hückel-type molecular orbital calculation.{{Cite journal |last1=Levenson |first1=Robert A. |last2=Gray |first2=Harry B. |last3=Ceasar |first3=Gerald P. |date=June 1970 |title=Electronic and vibrational spectroscopy in a nematic liquid crystal solvent. Band polarizations of binuclear metal carbonyls |url=https://pubs.acs.org/doi/abs/10.1021/ja00715a018 |journal=Journal of the American Chemical Society |language=en |volume=92 |issue=12 |pages=3653–3658 |doi=10.1021/ja00715a018 |bibcode=1970JAChS..92.3653L |issn=0002-7863|url-access=subscription }}{{Cite journal |last1=Levenson |first1=Robert A. |last2=Gray |first2=Harry B. |date=October 1975 |title=Electronic structure of compounds containing metal-metal bonds. Decacarbonyldimetal and related complexes |url=https://pubs.acs.org/doi/abs/10.1021/ja00854a015 |journal=Journal of the American Chemical Society |language=en |volume=97 |issue=21 |pages=6042–6047 |doi=10.1021/ja00854a015 |bibcode=1975JAChS..97.6042L |issn=0002-7863|url-access=subscription }} The electronic structure of Mn₂(CO)₁₀ was most reported in 2017 using the BP86D functional with TZP basis set.{{Cite journal |last1=Menacer |first1=Rafik |last2=May |first2=Abdelghani |last3=Belkhiri |first3=Lotfi |last4=Mousser |first4=Abdelhamid |date=2017-11-28 |title=Electronic structure and bonding of the dinuclear metal M2(CO)10 decacarbonyls: applications of natural orbitals for chemical valence |url=https://doi.org/10.1007/s00894-017-3523-5 |journal=Journal of Molecular Modeling |language=en |volume=23 |issue=12 |pages=358 |doi=10.1007/s00894-017-3523-5 |pmid=29185066 |s2cid=3814626 |issn=0948-5023|url-access=subscription }} The electronic structure described herein, along with relevant orbital plots, are reproduced from the methods used in that study using Orca (5.0.3){{Cite journal |last=Neese |first=Frank |date=January 2012 |title=The ORCA program system |url=https://onlinelibrary.wiley.com/doi/10.1002/wcms.81 |journal=WIREs Computational Molecular Science |language=en |volume=2 |issue=1 |pages=73–78 |doi=10.1002/wcms.81 |s2cid=62137389 |issn=1759-0876|url-access=subscription }} and visualized using IBOView (v20150427).{{Cite journal |last=Knizia |first=Gerald |date=2013-11-12 |title=Intrinsic Atomic Orbitals: An Unbiased Bridge between Quantum Theory and Chemical Concepts |url=https://pubs.acs.org/doi/10.1021/ct400687b |journal=Journal of Chemical Theory and Computation |language=en |volume=9 |issue=11 |pages=4834–4843 |doi=10.1021/ct400687b |pmid=26583402 |arxiv=1306.6884 |s2cid=17717923 |issn=1549-9618}} The two main interactions of interest in the system are the metal-to-ligand pi-backbonding interactions and the metal-metal sigma bonding orbital. The pi-backbonding interactions illustrated below occur between the t_2g d-orbital set and the CO π* antibonding orbitals. The degenerate d_xz and d_yz backbonding interactions with both axial and equatorial CO ligands is the HOMO-15. More total delocalization occurs onto the axial CO antibonding orbital than does the equatorial, which is thought to rationalize the shorter Mn-C bond length. The primary Mn-Mn σ-bonding orbital is composed of two d_z2 orbitals, represented by the HOMO-9.

Other large contributions made in this area were by Ahmed Zewail using ultrafast, femtosecond spectroscopy en route to his 1999 Nobel Prize.{{Citation |last=Zewail |first=Ahmed H. |title=Femtochemistry: Atomic-Scale Dynamics of the Chemical Bond Using Ultrafast Lasers (Nobel Lecture) |url=http://dx.doi.org/10.1002/3527600183.ch1 |work=Femtochemistry |year=2001 |pages=1–85 |access-date=2023-03-13 |place=Weinheim, FRG |publisher=Wiley-VCH Verlag GmbH|doi=10.1002/3527600183.ch1 |isbn=352730259X |url-access=subscription }} His discoveries elucidated much about the time scales and energies associated with the molecular motions of Mn₂(CO)₁₀, as well as the Mn-Mn and Mn-C bond cleavage events.{{Cite journal |last1=Kyu Kim |first1=Sang |last2=Pedersen |first2=Soren |last3=Zewail |first3=Ahmed H. |date=1995-02-24 |title=Femtochemistry of organometallics: dynamics of metal-metal and metal-ligand bond cleavage in M2(CO)10 |url=https://dx.doi.org/10.1016/0009-2614%2895%2900050-E |journal=Chemical Physics Letters |language=en |volume=233 |issue=5 |pages=500–508 |doi=10.1016/0009-2614(95)00050-E |bibcode=1995CPL...233..500K |issn=0009-2614|url-access=subscription }}

Mn₂(CO)₁₀ is air stable as a crystalline solid, but solutions require Schlenk techniques. Mn₂(CO)₁₀ is chemically active at both the Mn-Mn and Mn-CO bonds due to low, and similar, bond dissociation energies of ~36 kcal/mol (151 kJ/mol){{Cite journal |last1=Hughey |first1=Joseph L. |last2=Anderson |first2=Craig P. |last3=Meyer |first3=Thomas J. |date=1977-02-01 |title=Photochemistry of Mn2(CO)10 |url=https://www.sciencedirect.com/science/article/pii/S0022328X00894553 |journal=Journal of Organometallic Chemistry |language=en |volume=125 |issue=2 |pages=C49–C52 |doi=10.1016/S0022-328X(00)89455-3 |issn=0022-328X|url-access=subscription }} and ~38 kcal/mol (160 kJ/mol),{{Cite journal |last=Smith |first=G. P. |date=1988-01-01 |title=Gas-phase first bond dissociation energies in transition-metal carbonyls |url=https://www.sciencedirect.com/science/article/pii/S0277538700817854 |journal=Polyhedron |language=en |volume=7 |issue=16 |pages=1605–1608 |doi=10.1016/S0277-5387(00)81785-4 |issn=0277-5387|url-access=subscription }} respectively. For this reason, reactivity can happen at either site of the molecule, sometimes selectively.

The Mn-Mn bond is sensitive to both oxidation and reduction, producing two equivalents of the corresponding Mn(I) and Mn(-I) species, respectively. Both of the potential resultant species can be derived further. Redox neutral cleavage is possible both thermally and photochemically, producing two equivalents of the Mn(0) radical.

Selective mono-oxidation of the Mn-Mn bond is most often done via addition of classical metal oxidants (e.g. Ce^IV, Pb^IV, etc) or weak homonuclear single covalent bonds of the form X-X (X is group 16 or 17 element).{{Cite journal |last1=Davidson |first1=J. L. |last2=Sharp |first2=D. W. A. |date=1973-01-01 |title=Metal perfluoro-alkyl- and -aryl-thiolates. Part II. Molybdenum, tungsten, manganese, iron, and nickel derivatives |url=https://pubs.rsc.org/en/content/articlelanding/1973/dt/dt9730001957 |journal=Journal of the Chemical Society, Dalton Transactions |language=en |issue=19 |pages=1957–1960 |doi=10.1039/DT9730001957 |issn=1364-5447|url-access=subscription }}{{Cite journal |last1=Chaudhuri |first1=M. K. |last2=Haas |first2=A. |last3=Wensky |first3=A. |date=1976-08-24 |title=Photoinduced reactions of (CF3S)3N and CF3SeSeCF3 with Mn2(CO)10 and Fe(CO)5 |url=https://www.sciencedirect.com/science/article/pii/S0022328X00944693 |journal=Journal of Organometallic Chemistry |language=en |volume=116 |issue=3 |pages=323–326 |doi=10.1016/S0022-328X(00)94469-3 |issn=0022-328X|url-access=subscription }}{{Cite journal |last1=Arsenault |first1=Clément |last2=Bougeard |first2=Peter |last3=Sayer |first3=Brian G. |last4=Yeroushalmi |first4=Shahin |last5=McGlinchey |first5=Michael J. |date=1984-04-17 |title=[η5-1,2,3,4,5-pentakis(carbomethoxy)cyclopentadienyl]tricarbonylmanganese(I): Synthesis, spectroscopy and reactivity |url=https://dx.doi.org/10.1016/0022-328X%2884%2980092-3 |journal=Journal of Organometallic Chemistry |language=en |volume=265 |issue=3 |pages=283–290 |doi=10.1016/0022-328X(84)80092-3 |issn=0022-328X|url-access=subscription }}{{Cite journal |last1=Schmidt |first1=Steven P. |last2=Trogler |first2=William C. |last3=Basolo |first3=Fred |date=March 1984 |title=Mechanism of halogenation of dimanganese, manganese-rhenium, and dirhenium decacarbonyls |url=https://pubs.acs.org/doi/abs/10.1021/ja00317a023 |journal=Journal of the American Chemical Society |language=en |volume=106 |issue=5 |pages=1308–1313 |doi=10.1021/ja00317a023 |bibcode=1984JAChS.106.1308S |issn=0002-7863|url-access=subscription }}{{Cite journal |last1=Hernández |first1=José G. |last2=Butler |first2=Ian S. |last3=Friščić |first3=Tomislav |date=2014-06-16 |title=Multi-step and multi-component organometallic synthesis in one pot using orthogonal mechanochemical reactions |url=http://xlink.rsc.org/?DOI=C4SC01252F |journal=Chemical Science |language=en |volume=5 |issue=9 |pages=3576 |doi=10.1039/C4SC01252F |issn=2041-6520|url-access=subscription }} These reactions yield the [Mn(CO)₅]⁺ cation with a bound weakly coordinating anion, or the Mn(CO)₅X complex. The general reaction schemes for each are seen as balanced equations below:Mn2(CO)10 + 2 M^{n}X_{n} -> 2Mn(CO)5X + 2M^{(n-1)}X_{(n-1)}or for two-electron oxidantsMn2(CO)10 + M^{n}X_{n} -> 2Mn(CO)5X + M^{(n-2)}X_{(n-2)}andMn2(CO)10 + RE-ER -> 2Mn(CO)5(ER)for E = O, S, Se, TeMn2(CO)10 + X-X -> 2Mn(CO)5Xfor X = F, Cl, Br, I

Reductive cleavage is almost always done with sodium metal,{{Cite journal |last1=Warnock |first1=Garry F. P. |last2=Moodie |first2=Lyn Cammarano |last3=Ellis |first3=John E. |date=March 1989 |title=Highly reduced organometallics. Part 25. Reactions of trisodium tetracarbonylmetalates(3-) of manganese and rhenium with Broensted acids and other electrophiles. Synthesis of H2M(CO)4- (M = Mn and Re), (CH3)2Re(CO)4-, the first dialkyl derivative of a carbonylmetalate trianion, and related anionic species |url=https://pubs.acs.org/doi/abs/10.1021/ja00188a029 |journal=Journal of the American Chemical Society |language=en |volume=111 |issue=6 |pages=2131–2141 |doi=10.1021/ja00188a029 |bibcode=1989JAChS.111.2131W |issn=0002-7863|url-access=subscription }}{{Cite journal |last1=Kuchynka |first1=D. J. |last2=Kochi |first2=J. K. |date=March 1989 |title=Equilibrium of 17-electron and 19-electron organometallic radicals derived from carbonylmanganese anions and cations |url=https://pubs.acs.org/doi/abs/10.1021/ic00304a012 |journal=Inorganic Chemistry |language=en |volume=28 |issue=5 |pages=855–863 |doi=10.1021/ic00304a012 |issn=0020-1669|url-access=subscription }} yielding the [Mn(CO)₅]⁻ anion with the sodium counterion. The balanced general reactions are given below:Mn2(CO)10 + 2 Na^{0} -> 2Na[Mn(CO)5]The resultant manganate anion is a potent nucleophile, which can be protonated to give the manganese hydride,{{Cite journal |last1=Nappa |first1=Mario J. |last2=Santi |first2=Roberto |last3=Halpern |first3=Jack |date=January 1985 |title=Mechanisms of the carbon-hydrogen bond-forming binuclear reductive elimination reactions of benzyl- and hydridomanganese carbonyls |url=https://pubs.acs.org/doi/abs/10.1021/om00120a007 |journal=Organometallics |language=en |volume=4 |issue=1 |pages=34–41 |doi=10.1021/om00120a007 |issn=0276-7333|url-access=subscription }}{{Cite journal |last1=Wassink |first1=Berend |last2=Thomas |first2=Marian J. |last3=Wright |first3=Steven C. |last4=Gillis |first4=Daniel J. |last5=Baird |first5=Michael C. |date=April 1987 |title=Mechanisms of the hydrometalation (insertion) and stoichiometric hydrogenation reactions of conjugated dienes effected by manganese pentacarbonyl hydride: processes involving the radical pair mechanism |url=https://pubs.acs.org/doi/abs/10.1021/ja00241a016 |journal=Journal of the American Chemical Society |language=en |volume=109 |issue=7 |pages=1995–2002 |doi=10.1021/ja00241a016 |bibcode=1987JAChS.109.1995W |issn=0002-7863|url-access=subscription }} or alkylated with organic halides{{Cite journal |last1=Casey |first1=Charles P. |last2=Scheck |first2=Daniel M. |date=April 1980 |title=Mechanism of reductive elimination of acetophenone from Me4+[cis-(CO)4Mn(COMe)(COPh)]- |url=https://pubs.acs.org/doi/abs/10.1021/ja00528a034 |journal=Journal of the American Chemical Society |language=en |volume=102 |issue=8 |pages=2728–2731 |doi=10.1021/ja00528a034 |bibcode=1980JAChS.102.2728C |issn=0002-7863|url-access=subscription }}{{Cite journal |last1=Benson |first1=Ian B. |last2=Hunt |first2=James |last3=Knox |first3=Selby A. R. |last4=Oliphant |first4=Valerie |date=1978 |title=Organosulphur–transition-metal chemistry. Part 1. Reactions of carbon disulphide with metal carbonyl anions |url=http://xlink.rsc.org/?DOI=DT9780001240 |journal=J. Chem. Soc., Dalton Trans. |language=en |issue=10 |pages=1240–1246 |doi=10.1039/DT9780001240 |issn=0300-9246|url-access=subscription }} to give a large swath of organomanganese(I) complexes.

Further reduction gives Na₃Mn(CO)₄.{{Cite journal |last=Ellis |first=John E. |date=2006-04-17 |title=Adventures with Substances Containing Metals in Negative Oxidation States |url=https://pubs.acs.org/doi/10.1021/ic052110i |journal=Inorganic Chemistry |language=en |volume=45 |issue=8 |pages=3175–3176 |doi=10.1021/ic052110i |issn=0020-1669}}

Homolytic cleavage, usually via light,{{Cite journal |last1=Herrick |first1=Richard S. |last2=Brown |first2=Theodore L. |date=December 1984 |title=Flash photolytic investigation of photoinduced carbon monoxide dissociation from dinuclear manganese carbonyl compounds |url=https://pubs.acs.org/doi/abs/10.1021/ic00194a028 |journal=Inorganic Chemistry |language=en |volume=23 |issue=26 |pages=4550–4553 |doi=10.1021/ic00194a028 |issn=0020-1669|url-access=subscription }} but sometimes heat,{{Cite journal |last1=Wegman |first1=R. W. |last2=Olsen |first2=R. J. |last3=Gard |first3=D. R. |last4=Faulkner |first4=L. R. |last5=Brown |first5=Theodore L. |date=October 1981 |title=Flash photolysis study of the metal-metal bond homolysis in dimanganese decacarbonyl and dirhenium decacarbonyl |url=https://pubs.acs.org/doi/abs/10.1021/ja00410a017 |journal=Journal of the American Chemical Society |language=en |volume=103 |issue=20 |pages=6089–6092 |doi=10.1021/ja00410a017 |bibcode=1981JAChS.103.6089W |issn=0002-7863|url-access=subscription }} gives the Mn(0) metalloradical, which can react with itself to reform Mn₂(CO)₁₀, or combine with other radical species that usually result in formal oxidation to Mn(I). This reactivity is comparable to that of organic, carbon-based radicals via the isolobal analogy. The homolytic cleavage is given by:Mn2(CO)10 + h\nu -> 2[Mn(CO)5]^{.}The use of the produced radical species, [Mn(CO)₅]*, has found several applications as a radical initiator for various organic methodologies{{Cite journal |last1=Gilbert |first1=Bruce C. |last2=Kalz |first2=Wilhelm |last3=Lindsay |first3=Chris I. |last4=McGrail |first4=P. Terry |last5=Parsons |first5=Andrew F. |last6=Whittaker |first6=David T. E. |date=1999-08-13 |title=Radical cyclisations promoted by dimanganese decacarbonyl: A new and flexible approach to 5-membered N-heterocycles |url=https://www.sciencedirect.com/science/article/pii/S004040399901271X |journal=Tetrahedron Letters |language=en |volume=40 |issue=33 |pages=6095–6098 |doi=10.1016/S0040-4039(99)01271-X |issn=0040-4039|url-access=subscription }}{{Cite journal |last1=Gilbert |first1=Bruce C. |last2=Parsons |first2=Andrew F. |date=2002-02-25 |title=The use of free radical initiators bearing metal–metal, metal–hydrogen and non-metal–hydrogen bonds in synthesis |url=https://pubs.rsc.org/en/content/articlelanding/2002/p2/b102044g |journal=Journal of the Chemical Society, Perkin Transactions 2 |language=en |issue=3 |pages=367–387 |doi=10.1039/B102044G |issn=1364-5471|url-access=subscription }}{{Cite journal |last1=Fukuyama |first1=Takahide |last2=Nishitani |first2=Satoshi |last3=Inouye |first3=Takaya |last4=Morimoto |first4=Keisuke |last5=Ryu |first5=Ilhyong |date=2006-03-01 |title=Effective Acceleration of Atom Transfer Carbonylation of Alkyl Iodides by Metal Complexes. Application to the Synthesis of the Hinokinin Precursor and Dihydrocapsaicin |url=https://pubs.acs.org/doi/10.1021/ol060123%2B |journal=Organic Letters |language=en |volume=8 |issue=7 |pages=1383–1386 |doi=10.1021/ol060123+ |pmid=16562897 |issn=1523-7060|url-access=subscription }} and polymerization reactions.{{Cite journal |last1=Ciftci |first1=Mustafa |last2=Tasdelen |first2=Mehmet Atilla |last3=Yagci |first3=Yusuf |date=2013-12-11 |title=Sunlight induced atom transfer radical polymerization by using dimanganese decacarbonyl |url=https://pubs.rsc.org/en/content/articlelanding/2014/py/c3py01009k |journal=Polymer Chemistry |language=en |volume=5 |issue=2 |pages=600–606 |doi=10.1039/C3PY01009K |issn=1759-9962|url-access=subscription }}{{Cite journal |last1=Gilbert |first1=Bruce C. |last2=Harrison |first2=Richard J. |last3=Lindsay |first3=Chris I. |last4=McGrail |first4=P. Terry |last5=Parsons |first5=Andrew F. |last6=Southward |first6=Richard |last7=Irvine |first7=Derek J. |date=2003-12-01 |title=Polymerization of Methyl Methacrylate Using Dimanganese Decacarbonyl in the Presence of Organohalides |url=https://pubs.acs.org/doi/10.1021/ma034712w |journal=Macromolecules |language=en |volume=36 |issue=24 |pages=9020–9023 |doi=10.1021/ma034712w |bibcode=2003MaMol..36.9020G |issn=0024-9297|url-access=subscription }}{{Cite journal |last1=Ciftci |first1=Mustafa |last2=Norsic |first2=Sébastien |last3=Boisson |first3=Christophe |last4=D'Agosto |first4=Franck |last5=Yagci |first5=Yusuf |date=May 2015 |title=Synthesis of Block Copolymers Based on Polyethylene by Thermally Induced Controlled Radical Polymerization Using Mn 2 (CO) 10 |url=https://onlinelibrary.wiley.com/doi/10.1002/macp.201500016 |journal=Macromolecular Chemistry and Physics |language=en |volume=216 |issue=9 |pages=958–963 |doi=10.1002/macp.201500016|url-access=subscription }}

Ligand substitution reactions that do not disrupt the Mn-Mn bonding is done by using strongly sigma donating L-type ligands that can outcompete CO without participating in redox reactivity.{{Cite journal |last1=Coville |first1=N. J. |last2=Stolzenberg |first2=A. M. |last3=Muetterties |first3=E. L. |date=April 1983 |title=Mechanism of ligand substitution in dimanganese decacarbonyl |url=https://pubs.acs.org/doi/abs/10.1021/ja00346a079 |journal=Journal of the American Chemical Society |language=en |volume=105 |issue=8 |pages=2499–2500 |doi=10.1021/ja00346a079 |bibcode=1983JAChS.105.2499C |issn=0002-7863|url-access=subscription }} This requirement usually necessitates phosphines{{Cite journal |last1=Herrinton |first1=Thomas |last2=Brown |first2=Theodore |date=October 1, 1985 |title=Substitution of manganese pentacarbonyl is associative |url=https://pubs.acs.org/doi/10.1021/ja00306a016 |journal=Journal of the American Chemical Society |volume=107 |issue=20 |pages=5700–5703|doi=10.1021/ja00306a016 |bibcode=1985JAChS.107.5700H |url-access=subscription }}{{Cite journal |last1=Reimann |first1=Rolf H. |last2=Singleton |first2=Eric |date=1976-01-01 |title=Reactions of metal carbonyls. Part 7. Substitution reactions of decacarbonyldimanganese with tertiary phosphorus and arsenic ligands |url=https://pubs.rsc.org/en/content/articlelanding/1976/dt/dt9760002109 |journal=Journal of the Chemical Society, Dalton Transactions |language=en |issue=20 |pages=2109–2114 |doi=10.1039/DT9760002109 |issn=1364-5447|url-access=subscription }} or N-heterocyclic carbenes (NHCs),{{Cite journal |last1=Fraser |first1=Roan |last2=van Sittert |first2=Cornelia G. C. E. |last3=van Rooyen |first3=Petrus H. |last4=Landman |first4=Marilé |date=2017-05-01 |title=Synthesis and structural investigation of mono- and dimetallic N-heterocyclic carbene complexes of group VII transition metals |url=https://www.sciencedirect.com/science/article/pii/S0022328X17301158 |journal=Journal of Organometallic Chemistry |language=en |volume=835 |pages=60–69 |doi=10.1016/j.jorganchem.2017.02.031 |issn=0022-328X|url-access=subscription }} with substitution occurring at the axial position according to the reactions below:

File:Mn2(CO)10LigandSubstitution.png

Mn₂(CO)₁₀ is a volatile source of a metal and a source of CO.

{{Manganese compounds}}

{{Carbonyl complexes}}

{{DEFAULTSORT:Dimanganese Decacarbonyl}}

Category:Carbonyl complexes

Category:Organomanganese compounds

Category:Chemical compounds containing metal–metal bonds