Thioacetaldehyde

Formula: C₂H₄S
Molecular weight: 60.118
IUPAC Standard InChI: InChI=1S/C2H4S/c1-2-3/h2H,1H3
IUPAC Standard InChIKey: QJFUMFCCMJJLIE-UHFFFAOYSA-N
CAS Registry Number: 6851-93-0
Chemical structure:
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- Gas Phase Kinetics Database
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Gas phase ion energetics data

Go To: Top, Vibrational and/or electronic energy levels, References, Notes

Data compiled as indicated in comments:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi

View reactions leading to C₂H₄S⁺ (ion structure unspecified)

Ionization energy determinations

IE (eV)	Method	Reference	Comment
9.3	PE	Rao, 1975	Vertical value; LLK
8.98 ± 0.02	PE	Kroto, Landsberg, et al., 1974	Vertical value; LLK

De-protonation reactions

C₂H₃S^- + = Thioacetaldehyde

By formula: C₂H₃S^- + H⁺ = C₂H₄S

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	347.8 ± 3.4	kcal/mol	G+TS	Zhang and Grabowski, 1989	gas phase; Between MeCO2H, EtCO2H (Acid = MeCH=S); B
Δ_rH°	349.1 ± 4.1	kcal/mol	G+TS	Guillemin, Riague, et al., 2005	gas phase; Acid: CH3CH=S; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	341.0 ± 3.0	kcal/mol	IMRB	Zhang and Grabowski, 1989	gas phase; Between MeCO2H, EtCO2H (Acid = MeCH=S); B
Δ_rG°	342.3 ± 3.8	kcal/mol	IMRB	Guillemin, Riague, et al., 2005	gas phase; Acid: CH3CH=S; B

Vibrational and/or electronic energy levels

Go To: Top, Gas phase ion energetics data, References, Notes

Data compiled by: Marilyn E. Jacox

State: F

Energy (cm^-1)	Med.	References


T_o = 51560 ± 200	gas	Judge, Moule, et al., 1983

State: ?

Energy (cm^-1)	Med.	References


T_o = 52770 ± 100	gas	Judge, Moule, et al., 1983

State: C

Energy (cm^-1)	Med.	References


T_o = 45260 ± 100	gas	Judge, Moule, et al., 1983

State: B

Energy (cm^-1)	Med.	References


T_x = 47600 ± 100	gas	Judge, Moule, et al., 1983

Vib. sym.	Approximate type of mode	cm^-1	Med.	Method	References


a'	C=S stretch	1154	gas	AB	Judge, Moule, et al., 1983

State: A

Energy (cm^-1)	Med.	References


T_o = 17900 ± 100	gas	Judge, Moule, et al., 1983

State: a

Energy (cm^-1)	Med.	Transition	λ_min (nm)	λ_max (nm)	References


T_o = 16294.9	gas	a-X	571	630	Judge, Moule, et al., 1983
					Judge, Moule, et al., 1987
					Moule, Bascal, et al., 1992

Vib. sym.	No.	Approximate type of mode	cm^-1	Med.	Method	References


a'	9	CS stretch	747.2	gas	AB LF	Judge, Moule, et al., 1987 Moule, Bascal, et al., 1992
	10	CCS deform.	283.9	gas	LF	Moule, Bascal, et al., 1992
a	14	Wag	249.4	gas	LF	Moule, Bascal, et al., 1992
	15	Torsion	52.0	gas	LF	Moule, Bascal, et al., 1992

State: X

No.	Approximate type of mode	cm^-1		Med.	Method	References


	CH stretch	3010.4	w	Ar	IR	Maier, Flogel, et al., 1991 Suzuki, Watanabe, et al., 1993
	CH stretch	2982.0	w	Ar	IR	Maier, Flogel, et al., 1991 Suzuki, Watanabe, et al., 1993
	CH stretch	2944.4	m	Ar	IR	Maier, Flogel, et al., 1991 Suzuki, Watanabe, et al., 1993
	CH stretch	2908.7	w	Ar	IR	Maier, Flogel, et al., 1991
		1435.3	m	Ar	IR	Maier, Flogel, et al., 1991 Suzuki, Watanabe, et al., 1993
		1433.4	w m	Ar	IR	Maier, Flogel, et al., 1991
		1357.7	s	Ar	IR	Maier, Flogel, et al., 1991 Suzuki, Watanabe, et al., 1993
		1345.6	vs	Ar	IR	Maier, Flogel, et al., 1991 Suzuki, Watanabe, et al., 1993
	C=S stretch	1240		gas	AB	Judge, Moule, et al., 1987
		1140.7	s	Ar	IR	Maier, Flogel, et al., 1991 Suzuki, Watanabe, et al., 1993
		1065.0	w m	Ar	IR	Maier, Flogel, et al., 1991 Suzuki, Watanabe, et al., 1993
		1020.2	w m	Ar	IR	Maier, Flogel, et al., 1991 Suzuki, Watanabe, et al., 1993
		820.1	w	Ar	IR	Maier, Flogel, et al., 1991 Suzuki, Watanabe, et al., 1993
		747.8	s	Ar	IR	Maier, Flogel, et al., 1991 Suzuki, Watanabe, et al., 1993
15	Torsion	163.0		gas	LF	Moule, Bascal, et al., 1992

Additional references: Jacox, 1994, page 363; Jacox, 1998, page 324; Kroto and Landsberg, 1976; Bruno, Moule, et al., 1989; Smeyers, Nino, et al., 1990

Notes

Weak

Medium

Strong

Very strong

Energy separation between the v = 0 levels of the excited and electronic ground states.

Energy separation between the band maximum of the excited electronic state and the v = 0 level of the ground state.

References

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, Notes

Rao, 1975
Rao, C.N.R., Lone-pair ionization bands of chromophores in the photoelectron spectra of organic molecules, Indian J. Chem., 1975, 13, 950. [all data]

Kroto, Landsberg, et al., 1974
Kroto, H.W.; Landsberg, B.M.; Suffolk, R.J.; Vodden, A., The photoelectron and microwave spectra of the unstable species thioacetaldehyde, CH₃CHS, and thioacetone, (CH₃)₂CS, Chem. Phys. Lett., 1974, 29, 265. [all data]

Zhang and Grabowski, 1989
Zhang, L.; Grabowski, J.J., The Gas-Phase Basicity and H/D Exchange Characteristics of the Parent Thiocarbonyl Enolate Anions, J. Chem. Soc. Chem. Comm. 1819, 1989. [all data]

Guillemin, Riague, et al., 2005
Guillemin, J.C.; Riague, E.H.; Gal, J.F.; Maria, P.C.; Mo, O.; Yanez, M., Acidity trends in alpha,beta-unsaturated sulfur, selenium, and tellurium derivatives: Comparison with C-, Si-, Ge-, Sn-, N-, P-, As-, and Sb-containing analogues, Chem. Eur. J., 2005, 11, 7, 2145-2153, https://doi.org/10.1002/chem.200400989 . [all data]

Judge, Moule, et al., 1983
Judge, R.H.; Moule, D.C.; Bruno, A.E.; Steer, R.P., Thioketone spectroscopy: An analysis of the lower electronic transitions in thioacetone and thioacetaldehyde, Chem. Phys. Lett., 1983, 102, 4, 385, https://doi.org/10.1016/0009-2614(83)87061-4 . [all data]

Judge, Moule, et al., 1987
Judge, R.H.; Moule, D.C.; Bruno, A.E.; Steer, R.P., Thiocarbonyl spectroscopy: Methyl torsional vibrations and internal rotational barriers of thioacetaldehyde in its a 3A' and X 1A' states, J. Chem. Phys., 1987, 87, 1, 60, https://doi.org/10.1063/1.453554 . [all data]

Moule, Bascal, et al., 1992
Moule, D.C.; Bascal, H.A.; Smeyers, Y.G.; Clouthier, D.J.; Karolczak, J.; Nino, A., An analysis of the methyl rotation and aldehyde wagging dynamics in the S0 (X 1A') and T1 (a 3A') states of thioacetaldehyde from pyrolysis jet spectra, J. Chem. Phys., 1992, 97, 6, 3964, https://doi.org/10.1063/1.462935 . [all data]

Maier, Flogel, et al., 1991
Maier, G.; Flogel, U.; Reisenauer, H.P.; Hess, B.A., Jr.; Schaad, L.J., HCl-Abspaltung aus Ethansulfenylchlorid und Chlordimethylsulfid, Chem. Ber., 1991, 124, 11, 2609, https://doi.org/10.1002/cber.19911241134 . [all data]

Suzuki, Watanabe, et al., 1993
Suzuki, E.; Watanabe, O.; Happoya, A.; Watari, E., Photolysis of 2-methylthietane and 2,4-dimethylthietane in argon matrices: Matrix infrared spectra of thioacetaldehyde, Vib. Spectrosc., 1993, 5, 3, 353, https://doi.org/10.1016/0924-2031(93)87011-H . [all data]

Jacox, 1994
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules, American Chemical Society, Washington, DC, 1994, 464. [all data]

Jacox, 1998
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules: supplement A, J. Phys. Chem. Ref. Data, 1998, 27, 2, 115-393, https://doi.org/10.1063/1.556017 . [all data]

Kroto and Landsberg, 1976
Kroto, H.W.; Landsberg, B.M., The microwave spectrum, substitution structure, internal rotation barrier, and dipole moment of thioacetaldehyde, CH3CHS, J. Mol. Spectrosc., 1976, 62, 3, 346, https://doi.org/10.1016/0022-2852(76)90275-7 . [all data]

Bruno, Moule, et al., 1989
Bruno, A.E.; Moule, D.C.; Steer, R.P., Decay dynamics of the lowest triplet and lowest excited singlet states of thioacetaldehyde and thioacetone, J. Photochem. Photobiol. A: Chem., 1989, 46, 2, 169, https://doi.org/10.1016/1010-6030(89)80003-6 . [all data]

Smeyers, Nino, et al., 1990
Smeyers, Y.G.; Nino, A.; Moule, D.C., Dynamical and spectroscopic studies of nonrigid molecules. Application to the visible spectrum of thioacetaldehyde, J. Chem. Phys., 1990, 93, 8, 5786, https://doi.org/10.1063/1.459574 . [all data]

Notes

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, References

Symbols used in this document:

Δ_rG° Free energy of reaction at standard conditions

Δ_rH° Enthalpy of reaction at standard conditions
Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions