Dicobalt octacarbonyl

Formula: C₈Co₂O₈
Molecular weight: 341.9472
IUPAC Standard InChI: InChI=1S/8CO.2Co/c8*1-2;;
IUPAC Standard InChIKey: NFWSABSVGZVHCA-UHFFFAOYSA-N
CAS Registry Number: 10210-68-1
Chemical structure:
This structure is also available as a 2d Mol file
Other names: Cobalt, di-μ-carbonylhexacarbonyldi-, (Co-Co); Cobalt carbonyl (Co2(CO)8); Cobalt tetracarbonyl dimer; Di-μ-carbonylhexacarbonyldicobalt; Dicobalt carbonyl (Co2(CO)8); Octacarbonyldicobalt; Co2(CO)8; Cobalt carbonyl; Cobalt, di-μ-carbonylhexacarbonyldi-; Cobalt octacarbonyl
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Other data available:
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Gas phase thermochemistry data

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Data compiled by: José A. Martinho Simões

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	-1183.0 ± 9.1	kJ/mol	Review	Martinho Simões
Δ_fH°_gas	-1185.2 ± 9.4	kJ/mol	Review	Martinho Simões
Δ_fH°_gas	-1184.1 ± 6.9	kJ/mol	Review	Martinho Simões	Selected data. Average of the values from Connor, Skinner, et al., 1973 and Gardner, Cartner, et al., 1975.

Condensed phase thermochemistry data

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Data compiled by: José A. Martinho Simões

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_solid	-1248.2 ± 8.5	kJ/mol	Review	Martinho Simões
Δ_fH°_solid	-1250.4 ± 8.8	kJ/mol	Review	Martinho Simões
Δ_fH°_solid	-1249.3 ± 6.1	kJ/mol	Review	Martinho Simões	Selected data. Average of the values from Connor, Skinner, et al., 1973 and Gardner, Cartner, et al., 1975.

Phase change data

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Data compiled as indicated in comments:
AC - William E. Acree, Jr., James S. Chickos
MS - José A. Martinho Simões

Quantity	Value	Units	Method	Reference	Comment
Δ_subH°	65.2 ± 3.3	kJ/mol	N/A	Pilcher and Skinner, 1983	See also Cardner, Gartner, et al., 1975.; AC
Δ_subH°	65.2 ± 3.3	kJ/mol	TD-HFC	Gardner, Cartner, et al., 1975	Another value for the enthalpy of sublimation has been reported: 75.3±6.3 Cartner, Robinson, et al., 1973.; MS

Enthalpy of sublimation

Δ_subH (kJ/mol)	Temperature (K)	Method	Reference	Comment
84.3 ± 0.5	271.	TE	Garner, Chandra, et al., 1995	Based on data from 264. to 278. K.; AC
103.8	301.5	A	Stephenson and Malanowski, 1987	Based on data from 288. to 315. K. See also Baev, 1968.; AC
75.3 ± 6.3	207. to 287.	EM	Cartner, Robinson, et al., 1973, 2	AC

Reaction thermochemistry data

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Data compiled by: José A. Martinho Simões

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Individual Reactions

Dicobalt octacarbonyl (solution) + (solution) = 2 (solution)

By formula: C₈Co₂O₈ (solution) + H₂ (solution) = 2C₄HCoO₄ (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	19.7 ± 0.8	kJ/mol	EqS	Rathke, Klingler, et al., 1992	solvent: Supercritical carbon dioxide; Temperature range: 333-453 K. The results corrected for 1 atm pressure of H2 are 16.7 kJ/mol and -17.6 J/(mol K) Rathke, Klingler, et al., 1992
Δ_rH°	13.0 ± 0.9	kJ/mol	EqS	Bor, 1986	solvent: n-Hexane; Temperature range: ca. 300-420 K
Δ_rH°	26.4	kJ/mol	KinS	Alemdaroglu, Penninger, et al., 1976	solvent: n-Heptane; The reaction enthalpy relies on the experimental values for the forward and reverse activation enthalpies, 72.4 and 46.0 kJ/mol, respectively Alemdaroglu, Penninger, et al., 1976. A rather different value has, however, been reported for the activation enthalpy of the forward reaction, 104.6 kJ/mol Ungváry, 1972
Δ_rH°	27.6	kJ/mol	EqS	Alemdaroglu, Penninger, et al., 1976	solvent: n-Heptane; Temperature range: 353-428 K
Δ_rH°	13.4	kJ/mol	EqS	Ungváry, 1972	solvent: n-Heptane; Temperature range: 307-428 K. The results corrected for 1 atm pressure of H2 are 18.0 kJ/mol and -10.9 J/(mol K) Rathke, Klingler, et al., 1992

Dicobalt octacarbonyl (g) = 2 (g)

By formula: C₈Co₂O₈ (g) = 2C₄CoO₄ (g)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	64.	kJ/mol	EST	Connor, 1977	Please also see Pilcher and Skinner, 1982 and Martinho Simões and Beauchamp, 1990. The enthalpy of formation relies on -1184.1 ± 6.9 kJ/mol for the enthalpy of formation of Co2(CO)8(g).
Δ_rH°	60. ± 13.	kJ/mol	EG/EIMS	Bidinosti and McIntyre, 1970	The reaction enthalpy includes an estimated correction to 298 K. A value of 60.7 ± 8.4 kJ/mol was reported at an average temperature of 330 K Bidinosti and McIntyre, 1970.

Dicobalt octacarbonyl (solution) = C₇Co₂O₇ (solution) + (solution)

By formula: C₈Co₂O₈ (solution) = C₇Co₂O₇ (solution) + CO (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	92.7	kJ/mol	KinS	Ungváry and Markó, 1974	solvent: Heptane; Temperature range: 298-328 K
Δ_rH°	87.9	kJ/mol	KinS	Ungváry, 1972	solvent: Heptane; Temperature range: 307-337 K

0.5 Dicobalt octacarbonyl (solution) + (cr) = C₄CoNaO₄ (solution)

By formula: 0.5C₈Co₂O₈ (solution) + Na (cr) = C₄CoNaO₄ (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-318. ± 11.	kJ/mol	RSC	Kiss, Nolan, et al., 1994	solvent: Tetrahydrofuran; The reaction enthalpy was calculated from the enthalpies of the following reactions: 0.5Co2(CO)8(solution) + (Na)(Ph2CO)(solution) = (Na)[Co(CO)4](solution) + Ph2CO(solution), -157. ± 11. kJ/mol, and Ph2CO(solution) + Na(cr) = (Na)(Ph2CO)(solution), -161.1 ± 2.5 kJ/mol Kiss, Nolan, et al., 1994.

(solution) + Dicobalt octacarbonyl (solution) = 2C₉CoMnO₉ (solution)

By formula: C₁₀Mn₂O₁₀ (solution) + C₈Co₂O₈ (solution) = 2C₉CoMnO₉ (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	3.3 ± 1.3	kJ/mol	EqS	Klingler R.J. and Rathke, 1992	solvent: Supercritical carbon dioxide; Temperature range: 353-453 K

2 Dicobalt octacarbonyl (solution) = C₁₂Co₄O₁₂ (solution) + 4 (solution)

By formula: 2C₈Co₂O₈ (solution) = C₁₂Co₄O₁₂ (solution) + 4CO (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	123.4 ± 2.1	kJ/mol	EqS	Bor and Dietler, 1980	solvent: Hexane; Temperature range: 378-418 K

C₁₃H₁₀NaO (solution) + 0.5 Dicobalt octacarbonyl (solution) = C₄CoNaO₄ (solution) + (solution)

By formula: C₁₃H₁₀NaO (solution) + 0.5C₈Co₂O₈ (solution) = C₄CoNaO₄ (solution) + C₁₃H₁₀O (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-157. ± 11.	kJ/mol	RSC	Kiss, Nolan, et al., 1994	solvent: Tetrahydrofuran

Dicobalt octacarbonyl (cr) = 8 (g) + 2 (cr)

By formula: C₈Co₂O₈ (cr) = 8CO (g) + 2Co (cr)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	364.0 ± 8.4	kJ/mol	TD-HFC	Connor, Skinner, et al., 1973	Please also see Pedley and Rylance, 1977.

Gas phase ion energetics data

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Data compiled as indicated in comments:
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Ionization energy determinations

IE (eV)	Method	Reference	Comment
8.3 ± 0.1	EI	Bidinosti and McIntyre, 1970	RDSH
8.12 ± 0.22	EI	Winters and Kiser, 1965	RDSH

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
CoCO⁺	14.4 ± 0.5	?	EI	Winters and Kiser, 1965	RDSH
Co₂CO⁺	16.7 ± 0.3	7CO	EI	Winters and Kiser, 1965	RDSH
CoC₂O₂⁺	12.7 ± 0.4	?	EI	Winters and Kiser, 1965	RDSH
Co₂C₂O₂⁺	14.7 ± 0.5	6CO	EI	Winters and Kiser, 1965	RDSH
CoC₃O₃⁺	10.9 ± 0.3	?	EI	Winters and Kiser, 1965	RDSH
CoC₄O₄⁺	8.8 ± 0.1	?	EI	Bidinosti and McIntyre, 1967	RDSH
Co₂C₄O₄⁺	12.2 ± 0.3	4CO	EI	Winters and Kiser, 1965	RDSH
Co₂C₅O₅⁺	10.1 ± 0.4	3CO	EI	Winters and Kiser, 1965	RDSH
Co₂C₆O₆⁺	9.4 ± 0.3	2CO	EI	Winters and Kiser, 1965	RDSH
Co₂C₇O₇⁺	8.6 ± 0.3	CO	EI	Winters and Kiser, 1965	RDSH
Co⁺	16.9 ± 0.4	?	EI	Winters and Kiser, 1965	RDSH
Co₂⁺	17.8 ± 0.4	8CO	EI	Winters and Kiser, 1965	RDSH

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, Notes

Martinho Simões
Martinho Simões, J.A., Private communication (see http://webbook.nist.gov/chemistry/om/). [all data]

Connor, Skinner, et al., 1973
Connor, J.A.; Skinner, H.A.; Virmani, Y., High temperature microcalorimetric studies of the thermal decomposition and iodination of polynuclear carbonyls of Fe, Co, Ru, Rh, Re, Os and Ir, Faraday Symp. Chem. Soc., 1973, 8, 18, https://doi.org/10.1039/fs9730800018 . [all data]

Gardner, Cartner, et al., 1975
Gardner, P.J.; Cartner, A.; Cunninghame, R.G.; Robinson, B.H., J. Chem. Soc., Dalton Trans., 1975, 2582.. [all data]

Pilcher and Skinner, 1983
Pilcher, G.; Skinner, H.A., Thermochemistry of organometallic compounds, 1983, 43-90, https://doi.org/10.1002/9780470771686.ch2 . [all data]

Cardner, Gartner, et al., 1975
Cardner, Peter J.; Gartner, Anthony; Cunninghame, Robert G.; Robinson, Brian H., Bond energies in dicobalt octacarbonyl and bromo- and chloro-methylidynetricobalt enneacarbonyls, J. Chem. Soc., Dalton Trans., 1975, 23, 2582, https://doi.org/10.1039/dt9750002582 . [all data]

Cartner, Robinson, et al., 1973
Cartner, A.; Robinson, B.; Gardner, P.J., J. Chem. Soc., Chem. Commun., 1973, 317.. [all data]

Garner, Chandra, et al., 1995
Garner, M.L.; Chandra, D.; Lau, K.H., Low-temperature vapor pressures of W-, Cr-, and Co-carbonyls, JPE, 1995, 16, 1, 24-29, https://doi.org/10.1007/BF02646245 . [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

Baev, 1968
Baev, A.K., Vestsi Akad. Navak BSSR, Ser. Khim. Navuk, 1968, 4, 76. [all data]

Cartner, Robinson, et al., 1973, 2
Cartner, Anthony; Robinson, Brian; Gardner, Peter J., Heat of formation of dicobalt octacarbonyl and the metal?carbon monoxide bond strength in carbonyls, J. Chem. Soc., Chem. Commun., 1973, 9, 317b, https://doi.org/10.1039/c3973000317b . [all data]

Rathke, Klingler, et al., 1992
Rathke, J.W.; Klingler, R.J.; Krause, T.R., Organometallics, 1992, 11, 585. [all data]

Bor, 1986
Bor, G., Pure & Appl. Chem., 1986, 58, 543. [all data]

Alemdaroglu, Penninger, et al., 1976
Alemdaroglu, N.H.; Penninger, J.M.L.; Oltay, E., Monatsh. Chem., 1976, 107, 1043. [all data]

Ungváry, 1972
Ungváry, F., J. Organometal. Chem., 1972, 36, 363. [all data]

Connor, 1977
Connor, J.A., Top. Curr. Chem., 1977, 71, 71. [all data]

Pilcher and Skinner, 1982
Pilcher, G.; Skinner, H.A., In The Chemistry of the Metal-Carbon Bond Wiley: New York, Hartley, F. R.; Patai, S., ed(s)., 1982. [all data]

Martinho Simões and Beauchamp, 1990
Martinho Simões, J.A.; Beauchamp, J.L., Chem. Rev., 1990, 90, 629. [all data]

Bidinosti and McIntyre, 1970
Bidinosti, D.R.; McIntyre, N.S., Mass spectrometric study of the thermal decomposition of dimanganese decacarbonyl and dicobalt octacarbonyl, Can. J. Chem., 1970, 48, 593. [all data]

Ungváry and Markó, 1974
Ungváry, F.; Markó, L., J. Organometal. Chem., 1974, 71, 283. [all data]

Kiss, Nolan, et al., 1994
Kiss, G.; Nolan, S.P.; Hoff, C.D., Inorg. Chim. Acta, 1994, 227, 285. [all data]

Klingler R.J. and Rathke, 1992
Klingler R.J.; Rathke, J.W., Inorg. Chem., 1992, 31, 804. [all data]

Bor and Dietler, 1980
Bor, G.; Dietler, U.K., J. Organometal. Chem., 1980, 191, 295. [all data]

Pedley and Rylance, 1977
Pedley, J.B.; Rylance, J., Computer Analysed Thermochemical Data: Organic and Organometallic Compounds, University of Sussex, Brigton, 1977. [all data]

Winters and Kiser, 1965
Winters, R.E.; Kiser, R.W., Ions produced by electron impact with the dimetallic carbonyls of cobalt and manganese, J. Phys. Chem., 1965, 69, 1618. [all data]

Bidinosti and McIntyre, 1967
Bidinosti, D.R.; McIntyre, N.S., The metal-metal bond dissociation energy in cobalt octacarbonyl, Chem. Commun., 1967, 1. [all data]

Notes

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Symbols used in this document:

AE	Appearance energy
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_fH°_solid	Enthalpy of formation of solid at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions
Δ_rS°	Entropy of reaction at standard conditions
Δ_subH	Enthalpy of sublimation
Δ_subH°	Enthalpy of sublimation at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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