Phthalic anhydride

Formula: C₈H₄O₃
Molecular weight: 148.1156
IUPAC Standard InChI: InChI=1S/C8H4O3/c9-7-5-3-1-2-4-6(5)8(10)11-7/h1-4H
IUPAC Standard InChIKey: LGRFSURHDFAFJT-UHFFFAOYSA-N
CAS Registry Number: 85-44-9
Chemical structure:
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Other names: 1,3-Isobenzofurandione; ESEN; Phthalandione; Phthalic acid anhydride; Retarder AK; Retarder ESEN; Retarder PD; TGL 6525; Vulkalent B/C; 1,2-Benzenedicarboxylic anhydride; 1,3-Phthalandione; 1,2-Benzenedicarboxylic acid anhydride; 1,3-Dioxophthalan; o-Phthalic acid anhydride; Anhydride phtalique; Anidride ftalica; Ftaalzuuranhydride; Ftalowy bezwodnik; Isobenzofuran, 1,3-dihydro-1,3-dioxo-; NCI-C03601; Phthalsaeureanhydrid; Anhydrid kyseliny ftalove; Ftalanhydrid; Rcra waste number U190; Araldite HT 901; Phthalanhydride; Sconoc 7; HT 901; Isobenzofuran-1,3-dione; Retarder PX; NSC 10431
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Condensed phase thermochemistry data

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Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_solid	-460.37	kJ/mol	Ccb	Parks, Mosley, et al., 1950	see Richardson and Parks, 1939; ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_solid	-3259.4	kJ/mol	Ccb	Parks, Mosley, et al., 1950	see Richardson and Parks, 1939; Corresponding Δ_fHº_solid = -460.32 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity	Value	Units	Method	Reference	Comment
S°_{solid,1 bar}	180.0	J/mol*K	N/A	Busygina, Maslova, et al., 1987	DH
S°_{solid,1 bar}	179.5	J/mol*K	N/A	Parks, Todd, et al., 1936	Extrapolation below 90 K, 58.12 J/mol*K.; DH

Constant pressure heat capacity of solid

C_p,solid (J/mol*K)	Temperature (K)	Reference	Comment
160.0	298.15	Busygina, Maslova, et al., 1987	T = 13 to 350 K.; DH
161.80	298.1	Parks, Todd, et al., 1936	T = 90 to 300 K.; DH

Gas phase ion energetics data

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

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

Electron affinity determinations

EA (eV)	Method	Reference	Comment
1.245 ± 0.087	TDEq	Paul and Kebarle, 1989	ΔGea(423 K) = -27.4±1 kcal/mol, ΔS = 3±3 eu; B
1.279 ± 0.048	IMRE	Fukuda and McIver, 1985	ΔGea(355 K) = -28.4 kcal/mol; ΔSea =-3.0, est. from data in Paul and Kebarle, 1989; B

Ionization energy determinations

IE (eV)	Method	Reference	Comment
10.1	PE	Dewar and Tien, 1985	LBLHLM
10.25 ± 0.05	PE	Galasso, Colonna, et al., 1977	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
C₆H₄⁺	13.2 ± 0.2	?	EI	Grutzmacher and Lohmann, 1967	RDSH

References

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

Parks, Mosley, et al., 1950
Parks, G.S.; Mosley, J.R.; Peterson, P.V., Jr., Heats of combustion and formation of some organic compounds containing oxygen, J. Chem. Phys., 1950, 18, 152. [all data]

Richardson and Parks, 1939
Richardson, J.W.; Parks, G.S., Thermal data on organic compounds. XIX. Modern combustion data for some non-volatile compounds containing carbon, hydrogen and oxygen, J. Am. Chem. Soc., 1939, 61, 3543-3546. [all data]

Busygina, Maslova, et al., 1987
Busygina, G.I.; Maslova, V.A.; Shvetsova, K.G.; Babinkov, A.G.; Rabinovich, I.B.; Karyakin, N.V., Specific heat and thermodynamic functions of phthalic anhydride and 2-ethylhexanol at 13-350 K, Zhur. Fiz. Khim., 1987, 61, 2347-2351. [all data]

Parks, Todd, et al., 1936
Parks, G.S.; Todd, S.S.; Moore, W.A., Thermal data on organic compounds. XVI. Some heat capacity, entropy and free energy data for typical benzene derivatives and heterocyclic compounds, J. Am. Chem. Soc., 1936, 58, 398-401. [all data]

Paul and Kebarle, 1989
Paul, G.; Kebarle, P., Electron Affinities of Cyclic Unsaturated Dicarbonyls: Maleic Anhydrides, Maleimides, and Cyclopentendione, J. Am. Chem. Soc., 1989, 111, 2, 464, https://doi.org/10.1021/ja00184a009 . [all data]

Fukuda and McIver, 1985
Fukuda, E.K.; McIver, R.T., Jr., Relative electron affinities of substituted benzophenones, nitrobenzenes, and quinones. [Anchored to EA(SO₂) from 74CEL/BEN], J. Am. Chem. Soc., 1985, 107, 2291. [all data]

Dewar and Tien, 1985
Dewar, M.J.S.; Tien, T.-P., Photoelectron spectrum of benzyne, J. Chem. Soc., Chem. Commun., 1985, 1243. [all data]

Galasso, Colonna, et al., 1977
Galasso, V.; Colonna, F.P.; Distefano, G., Photoelectron spectra of 1,2-indandione, 1,3-indandione and heterocyclic analogues, J. Electron Spectrosc. Relat. Phenom., 1977, 10, 227. [all data]

Grutzmacher and Lohmann, 1967
Grutzmacher, H.-F.; Lohmann, J., Massenspektrometrie instabiler organischer Molekule. I. Ionisations-potential und Bildungsenthalpie von Dehydrobenzol, Ann. Chem., 1967, 705, 81. [all data]

Notes

Go To: Top, Condensed phase thermochemistry data, Gas phase ion energetics data, References

Symbols used in this document:

AE	Appearance energy
C_p,solid	Constant pressure heat capacity of solid
EA	Electron affinity
S°_{solid,1 bar}	Entropy of solid at standard conditions (1 bar)
Δ_cH°_solid	Enthalpy of combustion of solid at standard conditions
Δ_fH°_solid	Enthalpy of formation of solid at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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