cyclopentadienide anion


Reaction thermochemistry data

Go To: Top, Gas phase ion energetics data, Ion clustering 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:
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

cyclopentadienide anion + Hydrogen cation = 1,3-Cyclopentadiene

By formula: C5H5- + H+ = C5H6

Quantity Value Units Method Reference Comment
Δr353.9 ± 2.2kcal/molG+TSBartmess, Scott, et al., 1979gas phase; value altered from reference due to change in acidity scale; B
Δr354.9 ± 2.9kcal/molG+TSCumming and Kebarle, 1978gas phase; B
Δr357.2 ± 2.0kcal/molD-EAEngelking and Lineberger, 1977gas phase; B
Quantity Value Units Method Reference Comment
Δr347.7 ± 2.0kcal/molIMREBartmess, Scott, et al., 1979gas phase; value altered from reference due to change in acidity scale; B
Δr348.7 ± 2.0kcal/molIMRECumming and Kebarle, 1978gas phase; B

cyclopentadienide anion + 1,3-Cyclopentadiene = (cyclopentadienide anion • 1,3-Cyclopentadiene)

By formula: C5H5- + C5H6 = (C5H5- • C5H6)

Quantity Value Units Method Reference Comment
Δr<8.60kcal/molIMRBMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr20.cal/mol*KN/AMeot-ner, 1988gas phase; Entropy change calculated or estimated, DG<, ΔrH<; M
Quantity Value Units Method Reference Comment
Δr<2.6 ± 1.0kcal/molIMRBMeot-ner, 1988gas phase; B

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
3.6250.PHPMSMeot-ner, 1988gas phase; Entropy change calculated or estimated, DG<, ΔrH<; M

(cyclopentadienide anion • 2C2D3N) + C2D3N = (cyclopentadienide anion • 3C2D3N)

By formula: (C5H5- • 2C2D3N) + C2D3N = (C5H5- • 3C2D3N)

Quantity Value Units Method Reference Comment
Δr10.2kcal/molPHPMSMeot-ner, 1988gas phase; Entropy change calculated or estimated, ΔrH<, CD3CN; M
Quantity Value Units Method Reference Comment
Δr22.cal/mol*KN/AMeot-ner, 1988gas phase; Entropy change calculated or estimated, ΔrH<, CD3CN; M

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
5.1232.PHPMSMeot-ner, 1988gas phase; Entropy change calculated or estimated, ΔrH<, CD3CN; M

cyclopentadienide anion + Water = (cyclopentadienide anion • Water)

By formula: C5H5- + H2O = (C5H5- • H2O)

Quantity Value Units Method Reference Comment
Δr11.0 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr16.1cal/mol*KPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr6.2 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

cyclopentadienide anion + Benzyl alcohol = (cyclopentadienide anion • Benzyl alcohol)

By formula: C5H5- + C7H8O = (C5H5- • C7H8O)

Quantity Value Units Method Reference Comment
Δr19.2 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr29.8cal/mol*KPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr10.3 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

cyclopentadienide anion + Ethanol, 2,2,2-trifluoro- = (cyclopentadienide anion • Ethanol, 2,2,2-trifluoro-)

By formula: C5H5- + C2H3F3O = (C5H5- • C2H3F3O)

Quantity Value Units Method Reference Comment
Δr20.6 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr24.3cal/mol*KPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr13.3 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

cyclopentadienide anion + Acetone = (cyclopentadienide anion • Acetone)

By formula: C5H5- + C3H6O = (C5H5- • C3H6O)

Quantity Value Units Method Reference Comment
Δr13.5 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr21.8cal/mol*KPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr7.0 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

cyclopentadienide anion + 2-Propanol, 2-methyl- = (cyclopentadienide anion • 2-Propanol, 2-methyl-)

By formula: C5H5- + C4H10O = (C5H5- • C4H10O)

Quantity Value Units Method Reference Comment
Δr17.0 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr32.0cal/mol*KPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr7.4 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

(cyclopentadienide anion • C2D3N) + C2D3N = (cyclopentadienide anion • 2C2D3N)

By formula: (C5H5- • C2D3N) + C2D3N = (C5H5- • 2C2D3N)

Quantity Value Units Method Reference Comment
Δr13.1kcal/molPHPMSMeot-ner, 1988gas phase; CD3CN; M
Quantity Value Units Method Reference Comment
Δr22.8cal/mol*KPHPMSMeot-ner, 1988gas phase; CD3CN; M

cyclopentadienide anion + Methyl Alcohol = (cyclopentadienide anion • Methyl Alcohol)

By formula: C5H5- + CH4O = (C5H5- • CH4O)

Quantity Value Units Method Reference Comment
Δr13.2 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B
Quantity Value Units Method Reference Comment
Δr6.9 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

cyclopentadienide anion + Acetonitrile = (cyclopentadienide anion • Acetonitrile)

By formula: C5H5- + C2H3N = (C5H5- • C2H3N)

Quantity Value Units Method Reference Comment
Δr15.5 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B
Quantity Value Units Method Reference Comment
Δr8.7 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

(cyclopentadienide anion • Water) + Water = (cyclopentadienide anion • 2Water)

By formula: (C5H5- • H2O) + H2O = (C5H5- • 2H2O)

Quantity Value Units Method Reference Comment
Δr10.0kcal/molPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr17.4cal/mol*KPHPMSMeot-ner, 1988gas phase; M

(cyclopentadienide anion • Acetone) + Acetone = (cyclopentadienide anion • 2Acetone)

By formula: (C5H5- • C3H6O) + C3H6O = (C5H5- • 2C3H6O)

Quantity Value Units Method Reference Comment
Δr9.8kcal/molPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr16.4cal/mol*KPHPMSMeot-ner, 1988gas phase; M

cyclopentadienide anion + C2D3N = (cyclopentadienide anion • C2D3N)

By formula: C5H5- + C2D3N = (C5H5- • C2D3N)

Quantity Value Units Method Reference Comment
Δr15.5kcal/molPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr22.8cal/mol*KPHPMSMeot-ner, 1988gas phase; M

cyclopentadienide anion + CCoO = C6H5CoO-

By formula: C5H5- + CCoO = C6H5CoO-

Quantity Value Units Method Reference Comment
Δr10.20 ± 0.80kcal/molN/ASunderlin and Squires, 1999gas phase; B

cyclopentadienide anion + cobalt = C5H5Co-

By formula: C5H5- + Co = C5H5Co-

Quantity Value Units Method Reference Comment
Δr7.00 ± 0.60kcal/molN/ASunderlin and Squires, 1999gas phase; B

Gas phase ion energetics data

Go To: Top, Reaction thermochemistry data, Ion clustering 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 by: John E. Bartmess

Protonation reactions

cyclopentadienide anion + Hydrogen cation = 1,3-Cyclopentadiene

By formula: C5H5- + H+ = C5H6

Quantity Value Units Method Reference Comment
Δr353.9 ± 2.2kcal/molG+TSBartmess, Scott, et al., 1979gas phase; value altered from reference due to change in acidity scale
Δr354.9 ± 2.9kcal/molG+TSCumming and Kebarle, 1978gas phase
Δr357.2 ± 2.0kcal/molD-EAEngelking and Lineberger, 1977gas phase
Quantity Value Units Method Reference Comment
Δr347.7 ± 2.0kcal/molIMREBartmess, Scott, et al., 1979gas phase; value altered from reference due to change in acidity scale
Δr348.7 ± 2.0kcal/molIMRECumming and Kebarle, 1978gas phase

Ion clustering data

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics 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:
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. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

cyclopentadienide anion + CCoO = C6H5CoO-

By formula: C5H5- + CCoO = C6H5CoO-

Quantity Value Units Method Reference Comment
Δr10.20 ± 0.80kcal/molN/ASunderlin and Squires, 1999gas phase; B

cyclopentadienide anion + Methyl Alcohol = (cyclopentadienide anion • Methyl Alcohol)

By formula: C5H5- + CH4O = (C5H5- • CH4O)

Quantity Value Units Method Reference Comment
Δr13.2 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B
Quantity Value Units Method Reference Comment
Δr6.9 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

cyclopentadienide anion + C2D3N = (cyclopentadienide anion • C2D3N)

By formula: C5H5- + C2D3N = (C5H5- • C2D3N)

Quantity Value Units Method Reference Comment
Δr15.5kcal/molPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr22.8cal/mol*KPHPMSMeot-ner, 1988gas phase; M

(cyclopentadienide anion • C2D3N) + C2D3N = (cyclopentadienide anion • 2C2D3N)

By formula: (C5H5- • C2D3N) + C2D3N = (C5H5- • 2C2D3N)

Quantity Value Units Method Reference Comment
Δr13.1kcal/molPHPMSMeot-ner, 1988gas phase; CD3CN; M
Quantity Value Units Method Reference Comment
Δr22.8cal/mol*KPHPMSMeot-ner, 1988gas phase; CD3CN; M

(cyclopentadienide anion • 2C2D3N) + C2D3N = (cyclopentadienide anion • 3C2D3N)

By formula: (C5H5- • 2C2D3N) + C2D3N = (C5H5- • 3C2D3N)

Quantity Value Units Method Reference Comment
Δr10.2kcal/molPHPMSMeot-ner, 1988gas phase; Entropy change calculated or estimated, ΔrH<, CD3CN; M
Quantity Value Units Method Reference Comment
Δr22.cal/mol*KN/AMeot-ner, 1988gas phase; Entropy change calculated or estimated, ΔrH<, CD3CN; M

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
5.1232.PHPMSMeot-ner, 1988gas phase; Entropy change calculated or estimated, ΔrH<, CD3CN; M

cyclopentadienide anion + Ethanol, 2,2,2-trifluoro- = (cyclopentadienide anion • Ethanol, 2,2,2-trifluoro-)

By formula: C5H5- + C2H3F3O = (C5H5- • C2H3F3O)

Quantity Value Units Method Reference Comment
Δr20.6 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr24.3cal/mol*KPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr13.3 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

cyclopentadienide anion + Acetonitrile = (cyclopentadienide anion • Acetonitrile)

By formula: C5H5- + C2H3N = (C5H5- • C2H3N)

Quantity Value Units Method Reference Comment
Δr15.5 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B
Quantity Value Units Method Reference Comment
Δr8.7 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

cyclopentadienide anion + Acetone = (cyclopentadienide anion • Acetone)

By formula: C5H5- + C3H6O = (C5H5- • C3H6O)

Quantity Value Units Method Reference Comment
Δr13.5 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr21.8cal/mol*KPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr7.0 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

(cyclopentadienide anion • Acetone) + Acetone = (cyclopentadienide anion • 2Acetone)

By formula: (C5H5- • C3H6O) + C3H6O = (C5H5- • 2C3H6O)

Quantity Value Units Method Reference Comment
Δr9.8kcal/molPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr16.4cal/mol*KPHPMSMeot-ner, 1988gas phase; M

cyclopentadienide anion + 2-Propanol, 2-methyl- = (cyclopentadienide anion • 2-Propanol, 2-methyl-)

By formula: C5H5- + C4H10O = (C5H5- • C4H10O)

Quantity Value Units Method Reference Comment
Δr17.0 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr32.0cal/mol*KPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr7.4 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

cyclopentadienide anion + 1,3-Cyclopentadiene = (cyclopentadienide anion • 1,3-Cyclopentadiene)

By formula: C5H5- + C5H6 = (C5H5- • C5H6)

Quantity Value Units Method Reference Comment
Δr<8.60kcal/molIMRBMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr20.cal/mol*KN/AMeot-ner, 1988gas phase; Entropy change calculated or estimated, DG<, ΔrH<; M
Quantity Value Units Method Reference Comment
Δr<2.6 ± 1.0kcal/molIMRBMeot-ner, 1988gas phase; B

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
3.6250.PHPMSMeot-ner, 1988gas phase; Entropy change calculated or estimated, DG<, ΔrH<; M

cyclopentadienide anion + Benzyl alcohol = (cyclopentadienide anion • Benzyl alcohol)

By formula: C5H5- + C7H8O = (C5H5- • C7H8O)

Quantity Value Units Method Reference Comment
Δr19.2 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr29.8cal/mol*KPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr10.3 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

cyclopentadienide anion + cobalt = C5H5Co-

By formula: C5H5- + Co = C5H5Co-

Quantity Value Units Method Reference Comment
Δr7.00 ± 0.60kcal/molN/ASunderlin and Squires, 1999gas phase; B

cyclopentadienide anion + Water = (cyclopentadienide anion • Water)

By formula: C5H5- + H2O = (C5H5- • H2O)

Quantity Value Units Method Reference Comment
Δr11.0 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B,M
Quantity Value Units Method Reference Comment
Δr16.1cal/mol*KPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr6.2 ± 1.0kcal/molTDAsMeot-ner, 1988gas phase; B

(cyclopentadienide anion • Water) + Water = (cyclopentadienide anion • 2Water)

By formula: (C5H5- • H2O) + H2O = (C5H5- • 2H2O)

Quantity Value Units Method Reference Comment
Δr10.0kcal/molPHPMSMeot-ner, 1988gas phase; M
Quantity Value Units Method Reference Comment
Δr17.4cal/mol*KPHPMSMeot-ner, 1988gas phase; M

References

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering 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, Gas phase ion energetics data, Ion clustering data, References