Ethyl formate

Formula: C₃H₆O₂
Molecular weight: 74.0785
IUPAC Standard InChI: InChI=1S/C3H6O2/c1-2-5-3-4/h3H,2H2,1H3
IUPAC Standard InChIKey: WBJINCZRORDGAQ-UHFFFAOYSA-N
CAS Registry Number: 109-94-4
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
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Isotopologues:
- Formic-d acid,ethylester
Other names: Formic acid, ethyl ester; Areginal; Ethyl methanoate; HCOOC2H5; Ethylformic ester; Aethylformiat; Ethyle (formiate d'); Ethylformiaat; Etile (formiato di); Mrowczan etylu; Ethylester kyseliny mravenci; Formic ether; UN 1190; Ethyl ester of formic acid; NSC 406578
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Gas phase thermochemistry data

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Data compiled as indicated in comments:
DRB - Donald R. Burgess, Jr.
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	-361.7	kJ/mol	N/A	Frolova and Petrov, 1991	Value computed using Δ_fH_liquid° value of -394.2±0.8 kj/mol from Frolova and Petrov, 1991 and Δ_vapH° value of 32.5 kj/mol from Hine and Klueppet, 1974.; DRB
Δ_fH°_gas	-398.	kJ/mol	Cm	Hine and Klueppet, 1974	ALS

Reaction thermochemistry data

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Data compiled as indicated in comments:
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

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Individual Reactions

C₃H₇O₂⁺ + Ethyl formate = (C₃H₇O₂⁺ • )

By formula: C₃H₇O₂⁺ + C₃H₆O₂ = (C₃H₇O₂⁺ • C₃H₆O₂)

Bond type: Hydrogen bonds of the type OH-O between organics

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	126.	kJ/mol	ICR	Larson and McMahon, 1982	gas phase; switching reaction((CH3)2OH+)(CH3)2O, Entropy change calculated or estimated; Grimsrud and Kebarle, 1973, Lias, Liebman, et al., 1984, Keesee and Castleman, 1986; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	129.	J/mol*K	N/A	Larson and McMahon, 1982	gas phase; switching reaction((CH3)2OH+)(CH3)2O, Entropy change calculated or estimated; Grimsrud and Kebarle, 1973, Lias, Liebman, et al., 1984, Keesee and Castleman, 1986; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	87.0	kJ/mol	ICR	Larson and McMahon, 1982	gas phase; switching reaction((CH3)2OH+)(CH3)2O, Entropy change calculated or estimated; Grimsrud and Kebarle, 1973, Lias, Liebman, et al., 1984, Keesee and Castleman, 1986; M

C₄H₉O₂⁺ + Ethyl formate = (C₄H₉O₂⁺ • )

By formula: C₄H₉O₂⁺ + C₃H₆O₂ = (C₄H₉O₂⁺ • C₃H₆O₂)

Bond type: Hydrogen bonds of the type OH-O between organics

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	128.	kJ/mol	ICR	Larson and McMahon, 1982	gas phase; switching reaction((CH3)2OH+)(CH3)2O, Entropy change calculated or estimated; Grimsrud and Kebarle, 1973, Lias, Liebman, et al., 1984, Keesee and Castleman, 1986; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	125.	J/mol*K	N/A	Larson and McMahon, 1982	gas phase; switching reaction((CH3)2OH+)(CH3)2O, Entropy change calculated or estimated; Grimsrud and Kebarle, 1973, Lias, Liebman, et al., 1984, Keesee and Castleman, 1986; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	90.4	kJ/mol	ICR	Larson and McMahon, 1982	gas phase; switching reaction((CH3)2OH+)(CH3)2O, Entropy change calculated or estimated; Grimsrud and Kebarle, 1973, Lias, Liebman, et al., 1984, Keesee and Castleman, 1986; M

+ Ethyl formate = ( • )

By formula: C₆H₅S^- + C₃H₆O₂ = (C₆H₅S^- • C₃H₆O₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	83.7	kJ/mol	PHPMS	Sieck and Meot-ner, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	107.	J/mol*K	PHPMS	Sieck and Meot-ner, 1989	gas phase; M

+ Ethyl formate = ( • )

By formula: I^- + C₃H₆O₂ = (I^- • C₃H₆O₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	69.5	kJ/mol	PHPMS	Caldwell and Kebarle, 1984	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	85.4	J/mol*K	PHPMS	Caldwell and Kebarle, 1984	gas phase; M

+ = Ethyl formate + +

By formula: C₈H₁₄N₂O₂ + H₂O = C₃H₆O₂ + C₃H₄N₂ + C₂H₆O

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-34.6 ± 1.8	kJ/mol	Cm	Guthrie and Pike, 1987	liquid phase; Heat of hydrolysis; ALS

+ = Ethyl formate + 2

By formula: C₇H₁₆O₃ + H₂O = C₃H₆O₂ + 2C₂H₆O

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-13.25 ± 0.79	kJ/mol	Cm	Hine and Klueppet, 1974	liquid phase; Heat of hydrolysis; ALS

+ = Ethyl formate + 2

By formula: C₅H₁₂O₃ + H₂O = C₃H₆O₂ + 2CH₄O

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-26.3 ± 2.7	kJ/mol	Cm	Hine and Klueppet, 1974	liquid phase; ALS

Gas phase ion energetics data

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Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard

View reactions leading to C₃H₆O₂⁺ (ion structure unspecified)

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	10.61 ± 0.01	eV	N/A	N/A	L
Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	799.4	kJ/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	768.4	kJ/mol	N/A	Hunter and Lias, 1998	HL

Ionization energy determinations

IE (eV)	Method	Reference	Comment
10.61 ± 0.05	PIPECO	Zha, Nishimura, et al., 1992	LL
10.61 ± 0.05	PE	Benoit, Harrison, et al., 1977	LLK
10.62	PE	Sweigart and Turner, 1972	LLK
10.61 ± 0.01	PI	Watanabe, Nakayama, et al., 1962	RDSH
10.61	PE	Benoit and Harrison, 1977	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
CHO⁺	12.7	H₂O+C₂H₃	EI	Holmes, Mommers, et al., 1985	LBLHLM
CHO⁺	11.39 ± 0.01	?	EI	Brion and Dunning, 1963	RDSH
CH₃⁺	11.07 ± 0.04	?	EI	Brion and Dunning, 1963	RDSH
CH₃O⁺	11.89 ± 0.07	CH₃+CO	PIPECO	Zha, Nishimura, et al., 1992	LL
CH₃O⁺	12.0 ± 0.1	?	EI	VanRaalte and Harrison, 1963	RDSH
CH₃O₂⁺	11.37 ± 0.08	C₂H₃	PIPECO	Zha, Nishimura, et al., 1992	LL
CH₃O₂⁺	11.02 ± 0.05	C₂H₃	EI	Holmes and Lossing, 1984	LBLHLM
CH₃O₂⁺	10.9 ± 0.05	C₂H₃	EI	Benoit, Harrison, et al., 1977	LLK
CH₃O₂⁺	11.3 ± 0.1	?	EI	Munson and Franklin, 1964	RDSH
CH₃O₂⁺	11.6 ± 0.1	?	EI	VanRaalte and Harrison, 1963	RDSH
C₂H₂⁺	14.9	?	EI	King and Long, 1958	RDSH
C₂H₃⁺	15.0	?	EI	King and Long, 1958	RDSH
C₂H₃O⁺	12.2	?	EI	King and Long, 1958	RDSH
C₂H₃O₂⁺	11.60 ± 0.16	CH₃	PIPECO	Zha, Nishimura, et al., 1992	LL
C₂H₃O₂⁺	11.5 ± 0.1	CH₃	EI	Godbole and Kebarle, 1962	RDSH
C₂H₄⁺	10.89 ± 0.05	CH₂O₂	PIPECO	Zha, Nishimura, et al., 1992	LL
C₂H₄⁺	11.2	?	EI	King and Long, 1958	RDSH
C₂H₅⁺	11.28 ± 0.25	HCO₂	PIPECO	Zha, Nishimura, et al., 1992	LL
C₂H₅⁺	12.0	?	EI	King and Long, 1958	RDSH
C₂H₅O⁺	11.40 ± 0.08	CHO	PIPECO	Zha, Nishimura, et al., 1992	LL
C₂H₅O⁺	11.34	CHO?	EI	Haney and Franklin, 1969	RDSH
C₃H₄O⁺	10.79 ± 0.05	H₂O	PIPECO	Zha, Nishimura, et al., 1992	LL
C₃H₅O₂⁺	11.1 ± 0.1	H	EI	Godbole and Kebarle, 1962	RDSH
H₃O⁺	11.8	C₂H₃+CO	EI	Holmes, Mommers, et al., 1985	LBLHLM

References

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

Frolova and Petrov, 1991
Frolova, E.I.; Petrov, A.A., Chemical equilibrium in the system formic acid-ethanol-ethyl formate-water, J. Appl. Chem. USSR, 1991, 64, 2361-2365. [all data]

Hine and Klueppet, 1974
Hine, J.; Klueppet, A.W., Structural effects on rates and equilibria. XVIII. Thermodynamic stability of ortho esters, J. Am. Chem. Soc., 1974, 96, 2924-2929. [all data]

Larson and McMahon, 1982
Larson, J.W.; McMahon, T.B., Formation, Thermochemistry, and Relative Stabilities of Proton - Bound dimers of Oxygen n - Donor Bases from Ion Cyclotron Resonance Solvent - Exchange Equilibria Measurements, J. Am. Chem. Soc., 1982, 104, 23, 6255, https://doi.org/10.1021/ja00387a016 . [all data]

Grimsrud and Kebarle, 1973
Grimsrud, E.P.; Kebarle, P., Gas Phase Ion Equilibria Studies of the Solvation of the Hydrogen Ion by Methanol, Dimethyl Ether and Water. Effect of Hydrogen Bonding, J. Am. Chem. Soc., 1973, 95, 24, 7939, https://doi.org/10.1021/ja00805a002 . [all data]

Lias, Liebman, et al., 1984
Lias, S.G.; Liebman, J.F.; Levin, R.D., Evaluated gas phase basicities and proton affinities of molecules heats of formation of protonated molecules, J. Phys. Chem. Ref. Data, 1984, 13, 695. [all data]

Keesee and Castleman, 1986
Keesee, R.G.; Castleman, A.W., Jr., Thermochemical data on Ggs-phase ion-molecule association and clustering reactions, J. Phys. Chem. Ref. Data, 1986, 15, 1011. [all data]

Sieck and Meot-ner, 1989
Sieck, L.W.; Meot-ner, M., Ionic Hydrogen Bond and Ion Solvation. 8. RS-..HOR Bond Strengths. Correlation with Acidities., J. Phys. Chem., 1989, 93, 4, 1586, https://doi.org/10.1021/j100341a079 . [all data]

Caldwell and Kebarle, 1984
Caldwell, G.; Kebarle, P., Binding energies and structural effects in halide anion-ROH and -RCOOH complexes from gas phase equilibria measurements, J. Am. Chem. Soc., 1984, 106, 967. [all data]

Guthrie and Pike, 1987
Guthrie, J.P.; Pike, D.C., Hydration of acylimidazoles: tetrahedral intermediates in acylimidazole hydrolysis and nucleophilic attack by imidazole on esters. The question of concerted mechanisms for acyl transfers, Can. J. Chem., 1987, 65, 1951-1969. [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Zha, Nishimura, et al., 1992
Zha, Q.; Nishimura, T.; Meisels, G.G., Unimolecular dissociation of energy-selected ethyl formate ions, Int. J. Mass Spectrom. Ion Processes, 1992, 120, 85. [all data]

Benoit, Harrison, et al., 1977
Benoit, F.M.; Harrison, A.G.; Lossing, F.P., Hydrogen migrations in mass spectrometry III-Energetics of formation of [R'CO₂H₂]⁺ in the mass spectra of R'CO₂R, Org. Mass Spectrom., 1977, 12, 78. [all data]

Sweigart and Turner, 1972
Sweigart, D.A.; Turner, D.W., Lone pair orbitals and their interactions studied by photoelectron spectroscopy. I. Carboxylic acids and their derivatives, J. Am. Chem. Soc., 1972, 94, 5592. [all data]

Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J., Ionization potentials of some molecules, J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]

Benoit and Harrison, 1977
Benoit, F.M.; Harrison, A.G., Predictive value of proton affinity. Ionization energy correlations involving oxygenated molecules, J. Am. Chem. Soc., 1977, 99, 3980. [all data]

Holmes, Mommers, et al., 1985
Holmes, J.; Mommers, A.; DeKoster, C.; Heerma, W.; Terlouw, J., Four isomeric [C,H₃,O₂] ions, Chem. Phys. Lett., 1985, 115, 437. [all data]

Brion and Dunning, 1963
Brion, C.E.; Dunning, W.J., Electron impact studies of simple carboxylic esters, J. Chem. Soc. Faraday Trans., 1963, 59, 647. [all data]

VanRaalte and Harrison, 1963
VanRaalte, D.; Harrison, A.G., Ionization and dissociation of formate esters by electron impact, Can. J. Chem., 1963, 41, 2054. [all data]

Holmes and Lossing, 1984
Holmes, J.L.; Lossing, F.P., Heats of formation of organic radicals from appearance energies, Int. J. Mass Spectrom. Ion Processes, 1984, 58, 113. [all data]

Munson and Franklin, 1964
Munson, M.S.B.; Franklin, J.L., Energetics of some gaseous oxygenated organic ions, J. Phys. Chem., 1964, 68, 3191. [all data]

King and Long, 1958
King, A.B.; Long, F.A., Mass spectra of some simple esters and their interpretation by quasi-equilibrium theory, J. Chem. Phys., 1958, 29, 374. [all data]

Godbole and Kebarle, 1962
Godbole, E.W.; Kebarle, P., Ionization and dissociation of deuterated ethyl and isopropyl acetates and ethyl formate under electron impact, J. Chem. Soc. Faraday Trans., 1962, 58, 1897. [all data]

Haney and Franklin, 1969
Haney, M.A.; Franklin, J.L., Excess energies in mass spectra of some oxygen-containing organic compounds, J. Chem. Soc. Faraday Trans., 1969, 65, 1794. [all data]

Notes

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Symbols used in this document:

AE	Appearance energy
IE (evaluated)	Recommended ionization energy
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions
Δ_rS°	Entropy of reaction at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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