chromium
- Formula: Cr
- Molecular weight: 51.9961
- IUPAC Standard InChIKey: VYZAMTAEIAYCRO-UHFFFAOYSA-N
- CAS Registry Number: 7440-47-3
- Chemical structure:
This structure is also available as a 2d Mol file - Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Data at other public NIST sites:
- NIST Atomic Spectra Database - Lines Holdings (on physics web site)
- NIST Atomic Spectra Database - Levels Holdings (on physics web site)
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- Gas Phase Kinetics Database
- X-ray Photoelectron Spectroscopy Database, version 5.0
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Gas phase thermochemistry data
Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | 95.000 | kcal/mol | Review | Chase, 1998 | Data last reviewed in June, 1973 |
Quantity | Value | Units | Method | Reference | Comment |
S°gas,1 bar | 41.661 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1973 |
Gas Phase Heat Capacity (Shomate Equation)
Cp° = A + B*t + C*t2 + D*t3 +
E/t2
H° − H°298.15= A*t + B*t2/2 +
C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 −
E/(2*t2) + G
Cp = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
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Temperature (K) | 2952.078 to 6000. |
---|---|
A | 2.759661 |
B | 3.276181 |
C | -0.817024 |
D | 0.094066 |
E | -3.994931 |
F | 91.47531 |
G | 43.71171 |
H | 95.00010 |
Reference | Chase, 1998 |
Comment | Data last reviewed in June, 1973 |
Condensed phase thermochemistry data
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°liquid | 6.231 | kcal/mol | Review | Chase, 1998 | Data last reviewed in June, 1973 |
Quantity | Value | Units | Method | Reference | Comment |
S°liquid,1 bar | 8.652 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1973 |
Quantity | Value | Units | Method | Reference | Comment |
S°solid | 5.645 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1973 |
Liquid Phase Heat Capacity (Shomate Equation)
Cp° = A + B*t + C*t2 + D*t3 +
E/t2
H° − H°298.15= A*t + B*t2/2 +
C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 −
E/(2*t2) + G
Cp = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
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Temperature (K) | 2130. to 2952.078 |
---|---|
A | 9.400110 |
B | 0.000000 |
C | 0.000000 |
D | 0.000000 |
E | 0.000000 |
F | 1.143631 |
G | 16.18330 |
H | 6.230412 |
Reference | Chase, 1998 |
Comment | Data last reviewed in June, 1973 |
Solid Phase Heat Capacity (Shomate Equation)
Cp° = A + B*t + C*t2 + D*t3 +
E/t2
H° − H°298.15= A*t + B*t2/2 +
C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 −
E/(2*t2) + G
Cp = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
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Temperature (K) | 298. to 600. | 600. to 2130. |
---|---|---|
A | 1.790091 | 4.413261 |
B | 17.09010 | 1.309271 |
C | -21.91100 | 1.889180 |
D | 11.00490 | -0.274342 |
E | 0.033020 | 0.302531 |
F | -1.010670 | -0.639804 |
G | 3.778471 | 11.49460 |
H | 0.000000 | 0.000000 |
Reference | Chase, 1998 | Chase, 1998 |
Comment | Data last reviewed in June, 1973 | Data last reviewed in June, 1973 |
Reaction thermochemistry data
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
B - John E. Bartmess
MS - José A. Martinho Simões
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.
Individual Reactions
By formula: Cr+ + Cr = (Cr+ • Cr)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 37. ± 5. | kcal/mol | ICRCD | Houriet and Vulpius, 1989 | gas phase; M |
ΔrH° | 42. | kcal/mol | EI | Hilpert and Ruthardt, 1987 | gas phase; from IP(Cr2) by EI and D(Cr2) by Knudsen cell, and IP(Cr); M |
ΔrH° | 43. ± 5. | kcal/mol | KC-MS | Hilpert and Ruthardt, 1987 | gas phase; data as evaluated by Houriet and Vulpius, 1989; M |
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
29.9 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
(CAS Reg. No. 136056-49-0 • 4294967295) +
= CAS Reg. No. 136056-49-0
By formula: (CAS Reg. No. 136056-49-0 • 4294967295Cr) + Cr = CAS Reg. No. 136056-49-0
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 88.4 ± 9.1 | kcal/mol | TDEq | Boltalina, Borshchevskii, et al., 1991 | gas phase; Data at 0 K. See also Pramann and Rademann, 1999; value altered from reference due to conversion from electron convention to ion convention; B |
By formula: C6CrO6 (cr) = 6CO (g) + Cr (cr)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 63.6 ± 1. | kcal/mol | TD-HFC | Al-Takhin, Connor, et al., 1984 | MS |
ΔrH° | 75.3 ± 0.2 | kcal/mol | TD-HZC | Pittam, Pilcher, et al., 1975 | Please also see Pedley and Rylance, 1977 and Tel'noi and Rabinovich, 1977.; MS |
ΔrH° | 64.4 ± 1.1 | kcal/mol | TD-HFC | Connor, Skinner, et al., 1972 | MS |
(CAS Reg. No. 135774-12-8 • 4294967295) +
= CAS Reg. No. 135774-12-8
By formula: (CAS Reg. No. 135774-12-8 • 4294967295Cr) + Cr = CAS Reg. No. 135774-12-8
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 29.3 ± 1.6 | kcal/mol | N/A | Casey, Villata, et al., 1991 | gas phase; See also Casey and Leopold, 1993 for more analysis.; B |
C14H10CrN2O4 (cr) = 2 (g) + 4
(g) +
(cr)
By formula: C14H10CrN2O4 (cr) = 2C4H4N2 (g) + 4CO (g) + Cr (cr)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | >47.6 | kcal/mol | TD-HFC | Adedeji, Connor, et al., 1978 | The reaction enthalpy is a low limit Adedeji, Connor, et al., 1978.; MS |
By formula: (Cr+ • 10Cr) + Cr = (Cr+ • 11Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
61.7 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 11Cr) + Cr = (Cr+ • 12Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
69.1 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 12Cr) + Cr = (Cr+ • 13Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
70.3 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 13Cr) + Cr = (Cr+ • 14Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
63.8 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 14Cr) + Cr = (Cr+ • 15Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
67.4 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 15Cr) + Cr = (Cr+ • 16Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
65.3 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 16Cr) + Cr = (Cr+ • 17Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
49.7 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 17Cr) + Cr = (Cr+ • 18Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
55.7 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 18Cr) + Cr = (Cr+ • 19Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
69.1 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 19Cr) + Cr = (Cr+ • 20Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
60.5 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 9Cr) + Cr = (Cr+ • 10Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
59.3 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 2Cr) + Cr = (Cr+ • 3Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
23.9 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 3Cr) + Cr = (Cr+ • 4Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
51.4 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 4Cr) + Cr = (Cr+ • 5Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
40.9 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 5Cr) + Cr = (Cr+ • 6Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
58.8 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 6Cr) + Cr = (Cr+ • 7Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
51.9 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 7Cr) + Cr = (Cr+ • 8Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
59.5 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • 8Cr) + Cr = (Cr+ • 9Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
55.4 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
By formula: (Cr+ • Cr) + Cr = (Cr+ • 2Cr)
Enthalpy of reaction
ΔrH° (kcal/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
46.4 | CID | Armentrout and Kickel, 1994 | gas phase; guided ion beam CID; M |
(CAS Reg. No. 64911-49-5 • 4294967295) +
= CAS Reg. No. 64911-49-5
By formula: (CAS Reg. No. 64911-49-5 • 4294967295Cr) + Cr = CAS Reg. No. 64911-49-5
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 96.8 ± 7.0 | kcal/mol | N/A | Wenthold, Gunion, et al., 1996 | gas phase; B |
CrF18P6 (cr) = (cr) + 6
(g)
By formula: CrF18P6 (cr) = Cr (cr) + 6F3P (g)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 73.0 ± 3.0 | kcal/mol | HAL-HFC | Brown and Connor, 1974 | MS |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Chase, 1998
Chase, M.W., Jr.,
NIST-JANAF Themochemical Tables, Fourth Edition,
J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]
Houriet and Vulpius, 1989
Houriet, R.; Vulpius, T.,
Formation of Metal Cluster Ions by Gas - Phase Ion - Molecule Reactions: the Bond Energies of Cr2+ and Mn2+,
Chem. Phys. Lett., 1989, 154, 5, 454, https://doi.org/10.1016/0009-2614(89)87130-1
. [all data]
Hilpert and Ruthardt, 1987
Hilpert, K.; Ruthardt, K.,
Determination of the dissociation energy of the Cr2 molecule,
Ber. Bunsen-Ges. Phys. Chem., 1987, 91, 724. [all data]
Armentrout and Kickel, 1994
Armentrout, P.B.; Kickel, B.L.,
Gas Phase Thermochemistry of Transition Metal Ligand Systems: Reassessment of Values and Periodic Trends, in Organometallic Ion Chemistry, B. S. Freiser, ed, 1994. [all data]
Boltalina, Borshchevskii, et al., 1991
Boltalina, O.V.; Borshchevskii, A.Y.; Sidorov, L.N.,
Thermochemistry of Chromium Gaseous Fluorides and Their Negative Ions,
Zh. Fiz. Khim. SSSR, 1991, 65, 884. [all data]
Pramann and Rademann, 1999
Pramann, A.; Rademann, K.,
Mass-spectrometric study of formation and stability of manganese and manganese oxide cluster anions,
Int. J. Mass Spectrom., 1999, 187, 673-683, https://doi.org/10.1016/S1387-3806(98)14197-0
. [all data]
Al-Takhin, Connor, et al., 1984
Al-Takhin, G.; Connor, J.A.; Skinner, H.A.; Zaharani-Moettar, M.T.,
J. Organomet. Chem., 1984, 260, 189. [all data]
Pittam, Pilcher, et al., 1975
Pittam, D.A.; Pilcher, G.; Barnes, D.S.; Skinner, H.A.; Todd, D.,
J. Less-Common Met., 1975, 42, 217. [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]
Tel'noi and Rabinovich, 1977
Tel'noi, V.I.; Rabinovich, I.B.,
Russ. Chem. Rev., 1977, 46, 689. [all data]
Connor, Skinner, et al., 1972
Connor, J.A.; Skinner, H.A.; Virmani, Y.,
Microcalorimetric studies. Thermal decomposition and iodination of metal carbonyls,
J. Chem. Soc., Faraday Trans. 1, 1972, 68, 0, 1754, https://doi.org/10.1039/f19726801754
. [all data]
Casey, Villata, et al., 1991
Casey, S.M.; Villata, P.W.; Bengali, A.A.; Cheng, C.-L.; Dick, J.P.; Fenn, P.T.; Leopold, D.G.,
A Study of Cr2 by Negative ion Photoelectron Spectroscopy,
J. Am. Chem. Soc., 1991, 113, 17, 6688, https://doi.org/10.1021/ja00017a058
. [all data]
Casey and Leopold, 1993
Casey, S.M.; Leopold, D.G.,
Negative Ion Photoelectron Spectroscopy of Cr2,
J. Phys. Chem., 1993, 97, 4, 816, https://doi.org/10.1021/j100106a005
. [all data]
Adedeji, Connor, et al., 1978
Adedeji, F.A.; Connor, J.A.; Demain, C.P.; Martinho Simões, J.A.; Skinner, H.A.; Zafarani- Moattar, M.T.,
J. Organometal. Chem., 1978, 149, 333. [all data]
Wenthold, Gunion, et al., 1996
Wenthold, P.G.; Gunion, R.F.; Lineberger, W.C.,
Ultraviolet Negative-ion Photoelectron Spectroscopy of the Chromium Oxide Negative Ion,
Chem. Phys. Lett., 1996, 258, 1-2, 101, https://doi.org/10.1016/0009-2614(96)00611-2
. [all data]
Brown and Connor, 1974
Brown, D.L.S.; Connor, J.A.,
Skinner, H. A. J. Chem. Soc., Faraday Trans. I, 1974, 70, 1649. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, References
- Symbols used in this document:
S°gas,1 bar Entropy of gas at standard conditions (1 bar) S°liquid,1 bar Entropy of liquid at standard conditions (1 bar) S°solid Entropy of solid at standard conditions T Temperature ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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