Allyl radical

Formula: C₃H₅
Molecular weight: 41.0718
IUPAC Standard InChI: InChI=1S/C3H5/c1-3-2/h3H,1-2H2
IUPAC Standard InChIKey: RMRFFCXPLWYOOY-UHFFFAOYSA-N
CAS Registry Number: 1981-80-2
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript.
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Gas phase thermochemistry data

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

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	40.9 ± 0.7	kcal/mol	N/A	Tsang, 1996

Vibrational and/or electronic energy levels

Go To: Top, Gas phase thermochemistry data, References, Notes

Data compiled by: Marilyn E. Jacox

State: 8s

Energy (cm^-1)	Med.	References


T_o = 63398 ± 5	gas	Wu, Li, et al., 2000
		Liang, Chen, et al., 2002

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


a₁	7	C₃ bend	446 ± 5	gas	MPI	Liang, Chen, et al., 2002

State: 7s

Energy (cm^-1)	Med.	References


T_o = 62620 ± 5	gas	Wu, Li, et al., 2000
		Liang, Chen, et al., 2002

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


a₁	7	C₃ bend	449 ± 5	gas	MPI	Liang, Chen, et al., 2002

State: 6s

Energy (cm^-1)	Med.	References


T_o = 61337 ± 5	gas	Wu, Li, et al., 2000
		Liang, Chen, et al., 2002

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


a₁	7	C₃ bend	439 ± 5	gas	MPI	Wu, Li, et al., 2000 Liang, Chen, et al., 2002

State: 5s

Energy (cm^-1)	Med.	References


T_o = 58979 ± 5	gas	Liang, Chen, et al., 2002

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


a₁	7	C₃ bend	436 ± 5	gas	MPI	Liang, Chen, et al., 2002

State: 4s

Energy (cm^-1)	Med.	References


T_o = 53708 ± 5	gas	Wu, Li, et al., 2000
		Liang, Chen, et al., 2002

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


a₁	6	C₃ stretch	1034 ± 5	gas	MPI	Wu, Li, et al., 2000 Liang, Chen, et al., 2002
	7	C₃ bend	429 ± 5	gas	MPI	Wu, Li, et al., 2000 Liang, Chen, et al., 2002

State: 3d

Energy (cm^-1)	Med.	References


T_o = 52114 ± 5	gas	Wu, Li, et al., 2000
		Liang, Chen, et al., 2002

State: D

Energy (cm^-1)	Med.	References


T_o = 41557.8 ± 0.5	gas	Blush, Minsek, et al., 1992
		Getty, Liu, et al., 1992

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


a₂	9	CH₂ a-twist	596	gas	Ra	Getty, Liu, et al., 1992
b₁	12	CH₂ s-twist	564	gas	Ra	Getty, Liu, et al., 1992

State: C

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


T_o = 40305.5 ± 0.5		gas	C-X	220	250	Callear and Lee, 1968
						Minsek, Blush, et al., 1992
						Blush, Minsek, et al., 1992
						Minsek and Chen, 1993
T_x = 47000	T	Ar	C-X			Maier, Reisenauer, et al., 1983

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


a₁	7	CCC bend	385 ± 2	gas	MPI	Minsek, Blush, et al., 1992 Minsek and Chen, 1993

State: B

Energy (cm^-1)	Med.	References


T_o = 40056.5 ± 0.5	gas	Hudgens and Dulcey, 1985
		Sappey and Weisshaar, 1987
		Blush, Minsek, et al., 1992
		Minsek and Chen, 1993

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


a₁	7	C₃ bend	379 ± 2	gas	MPI	Hudgens and Dulcey, 1985 Sappey and Weisshaar, 1987 Minsek and Chen, 1993
a₂	9	CH₂ a-twist	596 ± 2	gas	MPI	Minsek and Chen, 1993
b₁	12	CH₂ s-twist	491 ± 7	gas	MPI	Sappey and Weisshaar, 1987

State: A

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


T_o = 24492.1	gas	A-X	370	410	Currie and Ramsay, 1966
					Tonokura and Koshi, 2000
					Achkasova, Araki, et al., 2005
					Castiglione, Bach, et al., 2006
					Kim, Araki, et al., 2006
T_o = 24480	Ar	A-X	360	410	Maier, Reisenauer, et al., 1983

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


a	5	CH₂ s-rock	1032 ± 10	gas	CR PF	Currie and Ramsay, 1966 Tonokura and Koshi, 2000 Castiglione, Bach, et al., 2006
	7	CH₂ a-wag	553 ± 10	gas	PF	Castiglione, Bach, et al., 2006
	8	C₃ bend	339	gas	CR PF	Currie and Ramsay, 1966 Tonokura and Koshi, 2000 Achkasova, Araki, et al., 2005 Castiglione, Bach, et al., 2006
	9	CH₂ a-twist	101	gas	CR PF	Achkasova, Araki, et al., 2005 Castiglione, Bach, et al., 2006
b	12	C₃ a-stretch	1501 ± 10	gas	PF	Castiglione, Bach, et al., 2006
	14	CH rock	1232 ± 10	gas	CF PF	Currie and Ramsay, 1966 Tonokura and Koshi, 2000 Castiglione, Bach, et al., 2006
	15	CH₂ a-rock	934 ± 10	gas	CR PF	Currie and Ramsay, 1966 Tonokura and Koshi, 2000 Castiglione, Bach, et al., 2006
	16	Mixed	752 ± 10	gas	PF	Castiglione, Bach, et al., 2006

State: X

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


a₁	1	CH₂ s-stretch	3113.98		gas	LD CC	Uy, Davis, et al., 1998 DeSain, Thompson, et al., 1998
	1	CH₂ s-stretch	3109	w m	Ar	IR	Mal'tsev, Korolov, et al., 1982 Maier, Reisenauer, et al., 1983 Mal'tsev, Korolev, et al., 1984 Nandi, Arnold, et al., 2001
	2	CH stretch	3033.87		gas	LD	Han, Utkin, et al., 2002
	2	CH stretch	3052	w	Ar	IR	Mal'tsev, Korolov, et al., 1982 Maier, Reisenauer, et al., 1983 Mal'tsev, Korolev, et al., 1984 Nandi, Arnold, et al., 2001
	3	CH stretch	3023.46		gas	LD	Han, Utkin, et al., 2002
	3	CH stretch	3027	w	Ar	IR	Nandi, Arnold, et al., 2001
	4	CH₂ scissors	1488 ± 4		gas	Ra	Getty, Burmeister, et al., 1991 Getty and Kelly, 1992
	4	CH₂ scissors	1478	w	Ar	IR	Mal'tsev, Korolov, et al., 1982 Maier, Reisenauer, et al., 1983 Mal'tsev, Korolev, et al., 1984 Nandi, Arnold, et al., 2001
	5	Mixed	1245 ± 3		gas	Ra	Getty, Burmeister, et al., 1991 Getty and Kelly, 1992
	5	Mixed	1242	w	Ar	IR	Mal'tsev, Korolov, et al., 1982 Maier, Reisenauer, et al., 1983 Mal'tsev, Korolev, et al., 1984 Nandi, Arnold, et al., 2001
	6	Mixed	1066 ± 4		gas	Ra	Getty, Burmeister, et al., 1991 Getty and Kelly, 1992
	6	Mixed	990 ± 20		gas	PE	Wenthold, Polak, et al., 1996
	7	C₃ bend	427 ± 4		gas	MPI Ra	Hudgens and Dulcey, 1985 Sappey and Weisshaar, 1987 Getty, Burmeister, et al., 1991 Getty and Kelly, 1992 Minsek and Chen, 1993
	7	C₃ bend	427 ± 4		gas	PE	Wenthold, Polak, et al., 1996 Liang, Chen, et al., 2002
a₂	9	CH₂ a-twist	549 ± 4		gas	MPI Ra	Sappey and Weisshaar, 1987 Getty and Kelly, 1992 Getty, Liu, et al., 1993
b₁	10	CH OPLA	968	H	gas	Ra	Getty, Burmeister, et al., 1991
	10	CH OPLA	983.6	w m	Ar	IR	Mal'tsev, Korolov, et al., 1982 Maier, Reisenauer, et al., 1983 Mal'tsev, Korolev, et al., 1984 Holtzhauer, Cometta-Morini, et al., 1990 Nandi, Arnold, et al., 2001
	11	CH₂ s-wag	801.72		gas	DL PE	Hirota, Yamada, et al., 1992 Wenthold, Polak, et al., 1996
	11	CH₂ s-wag	801.1	vs	Ar	IR	Jacox and Milligan, 1974 Mal'tsev, Korolov, et al., 1982 Maier, Reisenauer, et al., 1983 Mal'tsev, Korolev, et al., 1984 Holtzhauer, Cometta-Morini, et al., 1990 Huang and Graham, 1990 Nandi, Arnold, et al., 2001
	12	CH₂ s-twist	518 ± 4		gas	MPI Ra	Hudgens and Dulcey, 1985 Sappey and Weisshaar, 1987 Getty, Burmeister, et al., 1991 Getty and Kelly, 1992 Getty, Liu, et al., 1993 Minsek and Chen, 1993
	12	CH₂ s-twist	510.1	w m	Ar	IR	Mal'tsev, Korolov, et al., 1982 Maier, Reisenauer, et al., 1983 Mal'tsev, Korolev, et al., 1984 Holtzhauer, Cometta-Morini, et al., 1990 Huang and Graham, 1990 Nandi, Arnold, et al., 2001
b₂	13	CH₂ a-stretch	3110.60		gas	LD CC	Uy, Davis, et al., 1998 DeSain, Thompson, et al., 1998 DeSain and Curl, 1999
	13	CH₂ a-stretch	3107	w	Ar	IR	Nandi, Arnold, et al., 2001
	14	CH stretch	3020.32		gas	LD	Han, Utkin, et al., 2002
	14	CH stretch	3020	w	Ar	IR	Mal'tsev, Korolov, et al., 1982 Maier, Reisenauer, et al., 1983 Mal'tsev, Korolev, et al., 1984 Nandi, Arnold, et al., 2001
	15	CH₂ scissors	1464	w m	Ar	IR	Mal'tsev, Korolov, et al., 1982 Maier, Reisenauer, et al., 1983 Mal'tsev, Korolev, et al., 1984 Nandi, Arnold, et al., 2001
	16	Mixed	1390	w	Ar	IR	Mal'tsev, Korolov, et al., 1982 Maier, Reisenauer, et al., 1983 Mal'tsev, Korolev, et al., 1984 Nandi, Arnold, et al., 2001
	17	C₃ stretch	1182		Ar	IR	Mal'tsev, Korolev, et al., 1984 Nandi, Arnold, et al., 2001

Additional references: Jacox, 1994, page 372; Jacox, 1998, page 334; Jacox, 2003, page 356; Liu, Getty, et al., 1993; Schultz and Fischer, 1998

Notes

Weak

Medium

Very strong

(1/2)(2ν)

Tentative assignment or approximate value

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 thermochemistry data, Vibrational and/or electronic energy levels, Notes

Tsang, 1996
Tsang, W., Heats of Formation of Organic Free Radicals by Kinetic Methods in Energetics of Organic Free Radicals, Martinho Simoes, J.A.; Greenberg, A.; Liebman, J.F., eds., Blackie Academic and Professional, London, 1996, 22-58. [all data]

Wu, Li, et al., 2000
Wu, J.-C.; Li, R.; Chang, J.-L.; Chen, Y.-T., Rydberg states of the allyl radical observed by two-photon resonant ionization spectroscopy, J. Chem. Phys., 2000, 113, 17, 7286, https://doi.org/10.1063/1.1313560 . [all data]

Liang, Chen, et al., 2002
Liang, C.-W.; Chen, C.-C.; Wei, C.-Y.; Chen, Y.-T., Two-photon resonant ionization spectroscopy of the allyl-h[sub 5] and allyl-d[sub 5] radicals: Rydberg states and ionization energies, J. Chem. Phys., 2002, 116, 10, 4162, https://doi.org/10.1063/1.1450553 . [all data]

Blush, Minsek, et al., 1992
Blush, J.A.; Minsek, D.W.; Chen, P., Electronic spectrum of allyl and allyl-d5 radicals: the B[12A1] .rarw. X[12A2], C[22B1] .rarw. X[12A2], and D[12B2] .rarw. X[12A2] band systems, J. Phys. Chem., 1992, 96, 25, 10150, https://doi.org/10.1021/j100204a013 . [all data]

Getty, Liu, et al., 1992
Getty, J.D.; Liu, X.; Kelly, P.B., Vibronic coupling of the allyl radical excited states, J. Phys. Chem., 1992, 96, 25, 10155, https://doi.org/10.1021/j100204a014 . [all data]

Callear and Lee, 1968
Callear, A.B.; Lee, H.K., Electronic spectra of the free allyl radical and some of its simple derivatives, Trans. Faraday Soc., 1968, 64, 308, https://doi.org/10.1039/tf9686400308 . [all data]

Minsek, Blush, et al., 1992
Minsek, D.W.; Blush, J.A.; Chen, P., The 1 + 1 resonant multiphoton ionization spectrum of the allyl radical. Rotational structure in the ~C[22B1] .fwdarw. ~X[12A2] origin band, J. Phys. Chem., 1992, 96, 5, 2025, https://doi.org/10.1021/j100184a003 . [all data]

Minsek and Chen, 1993
Minsek, D.W.; Chen, P., The 1 + 1 and 2 + 2 resonant multiphoton ionization of allyl and allyl-dn (C3H5, C3H4D, C3HD4, and C3D5) radicals, J. Phys. Chem., 1993, 97, 50, 13375, https://doi.org/10.1021/j100152a050 . [all data]

Maier, Reisenauer, et al., 1983
Maier, G.; Reisenauer, H.P.; Rohde, B.; Dehnicke, K., IR-, UV- und ESR-Spektrum des Allylradikals in einer Argon-Matrix, Chem. Ber., 1983, 16, 2, 732, https://doi.org/10.1002/cber.19831160230 . [all data]

Hudgens and Dulcey, 1985
Hudgens, J.W.; Dulcey, C.S., Observation of the 3s 2A1 Rydberg states of allyl and 2-methylallyl radicals with multiphoton ionization spectroscopy, J. Phys. Chem., 1985, 89, 8, 1505, https://doi.org/10.1021/j100254a039 . [all data]

Sappey and Weisshaar, 1987
Sappey, A.D.; Weisshaar, J.C., Vibronic spectrum of cold, gas-phase allyl radicals by multiphoton ionization, J. Phys. Chem., 1987, 91, 14, 3731, https://doi.org/10.1021/j100298a004 . [all data]

Currie and Ramsay, 1966
Currie, C.L.; Ramsay, D.A., Electronic Absorption Spectrum and Dissociation Energy of the Allyl Radical, J. Chem. Phys., 1966, 45, 2, 488, https://doi.org/10.1063/1.1727594 . [all data]

Tonokura and Koshi, 2000
Tonokura, K.; Koshi, M., Absorption Spectrum and Cross Sections of the Allyl Radical Measured Using Cavity Ring-Down Spectroscopy: The Ã ← X Band, J. Phys. Chem. A, 2000, 104, 37, 8456, https://doi.org/10.1021/jp001129y . [all data]

Achkasova, Araki, et al., 2005
Achkasova, E.; Araki, M.; Denisov, A.; Maier, J.P., Rotational analysis of the electronic spectrum of the allyl radical, Mol. Phys., 2005, 103, 11-12, 1555, https://doi.org/10.1080/00268970500044830 . [all data]

Castiglione, Bach, et al., 2006
Castiglione, L.; Bach, A.; Chen, P., Spectroscopy and dynamics of A [2B1] allyl radical, Phys. Chem. Chem. Phys., 2006, 8, 22, 2591, https://doi.org/10.1039/b602412b . [all data]

Kim, Araki, et al., 2006
Kim, E.; Araki, M.; Chauhan, R.; Birza, P.; Maier, J.P., Electronic spectrum of the hydrocarbon cation, Mol. Phys.104, 2006, 104, 18, 2885, https://doi.org/10.1080/00268970600866694 . [all data]

Uy, Davis, et al., 1998
Uy, D.; Davis, S.; Nesbitt, D.J., High-resolution infrared spectroscopy of jet-cooled allyl radical (CH[sub 2]--CH--CH[sub 2]): In-phase (ν[sub 1]) and out-of-phase (ν[sub 13]) antisymmetric CH[sub 2] stretching vibrations, J. Chem. Phys., 1998, 109, 18, 7793, https://doi.org/10.1063/1.477425 . [all data]

DeSain, Thompson, et al., 1998
DeSain, J.D.; Thompson, R.I.; Sharma, S.D.; Curl, R.F., The rotationally resolved infrared spectrum of the ν[sub 1] stretch of the allyl radical, J. Chem. Phys., 1998, 109, 18, 7803, https://doi.org/10.1063/1.477426 . [all data]

Mal'tsev, Korolov, et al., 1982
Mal'tsev, A.K.; Korolov, V.A.; Nefedov, O.M., Izv. Akad. Nauk SSSR, 1982, Ser. Khim., 2415. [all data]

Mal'tsev, Korolev, et al., 1984
Mal'tsev, A.K.; Korolev, V.A.; Nefedov, O.M., Izv. Akad. Naul SSSR, 1984, Ser. Khim., 555. [all data]

Nandi, Arnold, et al., 2001
Nandi, S.; Arnold, P.A.; Carpenter, B.K.; Nimlos, M.R.; Dayton, D.C.; Ellison, G.B., Polarized Infrared Absorption Spectra of Matrix-Isolated Allyl Radicals, J. Phys. Chem. A, 2001, 105, 32, 7514, https://doi.org/10.1021/jp011163s . [all data]

Han, Utkin, et al., 2002
Han, J.-X.; Utkin, Yu.G.; Chen, H.-B.; Hunt, N.T.; Curl, R.F., High-resolution infrared spectra of jet-cooled allyl radical (CH[sub 2]--CH--CH[sub 2]): ν[sub 2], ν[sub 3], and ν[sub 14] C--H stretch vibrations, J. Chem. Phys., 2002, 116, 15, 6505, https://doi.org/10.1063/1.1459417 . [all data]

Getty, Burmeister, et al., 1991
Getty, J.D.; Burmeister, M.J.; Westre, S.G.; Kelly, P.B., Examination of allyl radical excited-state dynamics and ground-state vibrational frequencies by ultraviolet resonance Raman spectroscopy, M. Am. Chem. Soc., 1991, 113, 3, 801, https://doi.org/10.1021/ja00003a011 . [all data]

Getty and Kelly, 1992
Getty, J.D.; Kelly, P.B., Vibrational analysis of the X 2A2 state of the allyl radical, Chem. Phys., 1992, 168, 2-3, 357, https://doi.org/10.1016/0301-0104(92)87169-A . [all data]

Wenthold, Polak, et al., 1996
Wenthold, P.G.; Polak, M.L.; Lineberger, W.C., Photoelectron Spectroscopy of the Allyl and 2-Methylallyl Anions, J. Phys. Chem., 1996, 100, 17, 6920, https://doi.org/10.1021/jp953401n . [all data]

Getty, Liu, et al., 1993
Getty, J.D.; Liu, X.; Kelly, P.B., Anomalous polarization: evidence for vibronic coupling in the allyl radical, Chem. Phys. Lett., 1993, 201, 1-4, 236, https://doi.org/10.1016/0009-2614(93)85062-S . [all data]

Holtzhauer, Cometta-Morini, et al., 1990
Holtzhauer, K.; Cometta-Morini, C.; Oth, J.F.M., Photochemical electrocyclization of the allyl radical into the cyclopropyl radical, J. Phys. Org. Chem., 1990, 3, 4, 219, https://doi.org/10.1002/poc.610030403 . [all data]

Hirota, Yamada, et al., 1992
Hirota, E.; Yamada, C.; Okunishi, M., Infrared diode laser spectroscopy of the allyl radical. The ν11 band, J. Chem. Phys., 1992, 97, 5, 2963, https://doi.org/10.1063/1.463037 . [all data]

Jacox and Milligan, 1974
Jacox, M.E.; Milligan, D.E., Matrix isolation study of the vacuum ultraviolet photolysis of allene and methylacetylene. Vibrational and electronic spectra of the species C3, C3H, C3H2, and C3H3, Chem. Phys., 1974, 4, 1, 45, https://doi.org/10.1016/0301-0104(74)80047-9 . [all data]

Huang and Graham, 1990
Huang, J.W.; Graham, W.R.M., Fourier transform infrared study of tricarbon hydride radicals trapped in Ar at 10 K, J. Chem. Phys., 1990, 93, 3, 1583, https://doi.org/10.1063/1.459137 . [all data]

DeSain and Curl, 1999
DeSain, J.D.; Curl, R.F., Rotational Analysis of ν13 of Allyl Radical, J. Mol. Spectrosc., 1999, 196, 2, 324, https://doi.org/10.1006/jmsp.1999.7868 . [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]

Jacox, 2003
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules: supplement B, J. Phys. Chem. Ref. Data, 2003, 32, 1, 1-441, https://doi.org/10.1063/1.1497629 . [all data]

Liu, Getty, et al., 1993
Liu, X.; Getty, J.D.; Kelly, P.B., Resonance Raman spectrum of the allyl-d5 radical and the force field analysis of the allyl radical, J. Chem. Phys., 1993, 99, 3, 1522, https://doi.org/10.1063/1.465320 . [all data]

Schultz and Fischer, 1998
Schultz, T.; Fischer, I., Time-resolved photoelectron spectroscopy of the allyl radical: The lifetimes of the ultraviolet bands, J. Chem. Phys., 1998, 109, 14, 5812, https://doi.org/10.1063/1.477203 . [all data]

Notes

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

Symbols used in this document:

Δ_fH°_gas Enthalpy of formation of gas at standard conditions
Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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