cyclopentadienide anion
- Formula: C5H5-
- Molecular weight: 65.0937
- IUPAC Standard InChI: InChI=1S/C5H5/c1-2-4-5-3-1/h1-5H/q-1
- IUPAC Standard InChIKey: SINKOGOPEQSHQD-UHFFFAOYSA-N
- CAS Registry Number: 12127-83-2
- Chemical structure:
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Reaction thermochemistry data
Go To: Top, 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:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
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
+
=
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 1481. ± 9.2 | kJ/mol | G+TS | Bartmess, Scott, et al., 1979 | gas phase; value altered from reference due to change in acidity scale; B |
| ΔrH° | 1485. ± 12. | kJ/mol | G+TS | Cumming and Kebarle, 1978 | gas phase; B |
| ΔrH° | 1495. ± 8.4 | kJ/mol | D-EA | Engelking and Lineberger, 1977 | gas phase; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 1455. ± 8.4 | kJ/mol | IMRE | Bartmess, Scott, et al., 1979 | gas phase; value altered from reference due to change in acidity scale; B |
| ΔrG° | 1459. ± 8.4 | kJ/mol | IMRE | Cumming and Kebarle, 1978 | gas phase; B |
+
= (
•
)
By formula: C5H5- + C5H6 = (C5H5- • C5H6)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | <36.0 | kJ/mol | IMRB | Meot-ner, 1988 | gas phase; B,M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 84. | J/mol*K | N/A | Meot-ner, 1988 | gas phase; Entropy change calculated or estimated, DG<, ΔrH<; M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | <11. ± 4.2 | kJ/mol | IMRB | Meot-ner, 1988 | gas phase; B |
Free energy of reaction
| ΔrG° (kJ/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 15. | 250. | PHPMS | Meot-ner, 1988 | gas phase; Entropy change calculated or estimated, DG<, ΔrH<; M |
( • 2C2D3N) + C2D3N = (
• 3C2D3N)
By formula: (C5H5- • 2C2D3N) + C2D3N = (C5H5- • 3C2D3N)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 42.7 | kJ/mol | PHPMS | Meot-ner, 1988 | gas phase; Entropy change calculated or estimated, ΔrH<, CD3CN; M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 92. | J/mol*K | N/A | Meot-ner, 1988 | gas phase; Entropy change calculated or estimated, ΔrH<, CD3CN; M |
Free energy of reaction
| ΔrG° (kJ/mol) | T (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 21. | 232. | PHPMS | Meot-ner, 1988 | gas phase; Entropy change calculated or estimated, ΔrH<, CD3CN; M |
+
= (
•
)
By formula: C5H5- + H2O = (C5H5- • H2O)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 46.0 ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B,M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 67.4 | J/mol*K | PHPMS | Meot-ner, 1988 | gas phase; M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 26. ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B |
+
= (
•
)
By formula: C5H5- + C7H8O = (C5H5- • C7H8O)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 80.3 ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B,M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 125. | J/mol*K | PHPMS | Meot-ner, 1988 | gas phase; M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 43.1 ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B |
+
= (
•
)
By formula: C5H5- + C2H3F3O = (C5H5- • C2H3F3O)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 86.2 ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B,M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 102. | J/mol*K | PHPMS | Meot-ner, 1988 | gas phase; M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 55.6 ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B |
+
= (
•
)
By formula: C5H5- + C3H6O = (C5H5- • C3H6O)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 56.5 ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B,M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 91.2 | J/mol*K | PHPMS | Meot-ner, 1988 | gas phase; M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 29. ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B |
+
= (
•
)
By formula: C5H5- + C4H10O = (C5H5- • C4H10O)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 71.1 ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B,M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 134. | J/mol*K | PHPMS | Meot-ner, 1988 | gas phase; M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 31. ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B |
( • C2D3N) + C2D3N = (
• 2C2D3N)
By formula: (C5H5- • C2D3N) + C2D3N = (C5H5- • 2C2D3N)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 54.8 | kJ/mol | PHPMS | Meot-ner, 1988 | gas phase; CD3CN; M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 95.4 | J/mol*K | PHPMS | Meot-ner, 1988 | gas phase; CD3CN; M |
+
= (
•
)
By formula: C5H5- + CH4O = (C5H5- • CH4O)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 55.2 ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 29. ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B |
+
= (
•
)
By formula: C5H5- + C2H3N = (C5H5- • C2H3N)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 64.9 ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 36. ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B |
( •
) +
= (
• 2
)
By formula: (C5H5- • H2O) + H2O = (C5H5- • 2H2O)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 41.8 | kJ/mol | PHPMS | Meot-ner, 1988 | gas phase; M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 72.8 | J/mol*K | PHPMS | Meot-ner, 1988 | gas phase; M |
( •
) +
= (
• 2
)
By formula: (C5H5- • C3H6O) + C3H6O = (C5H5- • 2C3H6O)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 41. | kJ/mol | PHPMS | Meot-ner, 1988 | gas phase; M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 68.6 | J/mol*K | PHPMS | Meot-ner, 1988 | gas phase; M |
By formula: C5H5- + C2D3N = (C5H5- • C2D3N)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 64.9 | kJ/mol | PHPMS | Meot-ner, 1988 | gas phase; M |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 95.4 | J/mol*K | PHPMS | Meot-ner, 1988 | gas phase; M |
By formula: C5H5- + CCoO = C6H5CoO-
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 42.7 ± 3.3 | kJ/mol | N/A | Sunderlin and Squires, 1999 | gas phase; B |
+
= C5H5Co-
By formula: C5H5- + Co = C5H5Co-
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 29.3 ± 2.5 | kJ/mol | N/A | Sunderlin and Squires, 1999 | gas phase; B |
References
Go To: Top, Reaction thermochemistry data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Bartmess, Scott, et al., 1979
Bartmess, J.E.; Scott, J.A.; McIver, R.T., Jr.,
The gas phase acidity scale from methanol to phenol,
J. Am. Chem. Soc., 1979, 101, 6047. [all data]
Cumming and Kebarle, 1978
Cumming, J.B.; Kebarle, P.,
Summary of gas phase measurements involving acids AH. Entropy changes in proton transfer reactions involving negative ions. Bond dissociation energies D(A-H) and electron affinities EA(A),
Can. J. Chem., 1978, 56, 1. [all data]
Engelking and Lineberger, 1977
Engelking, P.C.; Lineberger, W.C.,
Laser photoelectron spectrometry of C5H5-: A determination of the electron affinity and Jahn-Teller coupling in cyclopentadienyl,
J. Chem. Phys., 1977, 67, 1412. [all data]
Meot-ner, 1988
Meot-ner, M.,
The Ionic Hydrogen Bond and Solvation. 7. Interaction Energies of Carbanions with Solvent Molecules,
J. Am. Chem. Soc., 1988, 110, 12, 3858, https://doi.org/10.1021/ja00220a022
. [all data]
Sunderlin and Squires, 1999
Sunderlin, L.S.; Squires, R.R.,
Bond strengths in cyclopentadienyl metal carbonyl anions,
Int. J. Mass Spectrom., 1999, 183, 149-161, https://doi.org/10.1016/S1387-3806(98)14230-6
. [all data]
Notes
Go To: Top, Reaction thermochemistry data, References
- Symbols used in this document:
T Temperature ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔrS° Entropy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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