α-Methylstyrene
- Formula: C9H10
- Molecular weight: 118.1757
- IUPAC Standard InChIKey: XYLMUPLGERFSHI-UHFFFAOYSA-N
- CAS Registry Number: 98-83-9
- 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. - Other names: Benzene, (1-methylethenyl)-; Styrene, α-methyl-; α-Methylstyrol; β-Phenylpropylene; Isopropenylbenzene; 1-Methyl-1-phenylethylene; 1-Phenyl-1-methylethylene; 1-Propene, 2-phenyl-; 2-Phenyl-1-propene; 2-Phenylpropene; (1-Methylethenyl)benzene; AS-Methylphenylethylene; β-phenylpropene; α-Methylstyreen; α-Metil-stirolo; Isopropenil-benzolo; Isopropenyl-benzeen; Isopropenyl-benzol; 2-Phenylpropylene; UN 2303; Benzene, isopropenyl-; 2-Phenyl-2-propene; 1-Methyl-1-phenylethene; NSC 9400; a-methylstyrene
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Phase change data
Go To: Top, 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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 438. ± 4. | K | AVG | N/A | Average of 15 out of 16 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 249.05 | K | N/A | Anonymous, 1952 | Uncertainty assigned by TRC = 0.3 K; TRC |
Tfus | 247.22 | K | N/A | Anonymous, 1946 | Uncertainty assigned by TRC = 0.6 K; TRC |
Tfus | 249.94 | K | N/A | Stull, 1945 | Uncertainty assigned by TRC = 0.25 K; TRC |
Tfus | 244.83 | K | N/A | Anonymous, 1943 | Uncertainty assigned by TRC = 0.4 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 645. | K | N/A | Steele, Chirico, et al., 1997 | Uncertainty assigned by TRC = 6. K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 35.50 | bar | N/A | Steele, Chirico, et al., 1997 | Uncertainty assigned by TRC = 3.00 bar; derived from fit of obs. vapor pressure; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.44 | mol/l | N/A | Steele, Chirico, et al., 1997 | Uncertainty assigned by TRC = 0.13 mol/l; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 48.9 ± 0.3 | kJ/mol | GS | Verevkin, 1999 | Based on data from 274. to 314. K.; AC |
ΔvapH° | 48.6 ± 0.4 | kJ/mol | EB | Steele, Chirico, et al., 1997, 2 | Based on data from 331. to 467. K.; AC |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
49.2 ± 0.3 | 294. | GS | Verevkin, 1999 | Based on data from 274. to 314. K.; AC |
45.9 ± 0.3 | 340. | EB | Steele, Chirico, et al., 1997, 2 | Based on data from 331. to 467. K.; AC |
43.3 ± 0.3 | 380. | EB | Steele, Chirico, et al., 1997, 2 | Based on data from 331. to 467. K.; AC |
40.6 ± 0.3 | 420. | EB | Steele, Chirico, et al., 1997, 2 | Based on data from 331. to 467. K.; AC |
37.7 ± 0.5 | 460. | EB | Steele, Chirico, et al., 1997, 2 | Based on data from 331. to 467. K.; AC |
44.3 | 358. | A | Stephenson and Malanowski, 1987 | Based on data from 343. to 493. K.; AC |
44.8 | 368. | A | Stephenson and Malanowski, 1987 | Based on data from 353. to 413. K.; AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)
View plot Requires a JavaScript / HTML 5 canvas capable browser.
Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
280.6 to 438.6 | 5.21967 | 2326.867 | 7.23 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
11.924 | 250.78 | Lebedev and Rabinovich, 1971 | DH |
11.92 | 250.8 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
47.55 | 250.78 | Lebedev and Rabinovich, 1971 | DH |
Gas phase ion energetics data
Go To: Top, Phase change data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
Data compiled as indicated in comments:
B - John E. Bartmess
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
View reactions leading to C9H10+ (ion structure unspecified)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Proton affinity (review) | 864.2 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 835.3 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
8.3 ± 0.1 | EI | Koppel, Schwarz, et al., 1974 | LLK |
8.18 ± 0.04 | EI | Benito, Seidl, et al., 1973 | LLK |
8.35 ± 0.01 | PI | Watanabe, Nakayama, et al., 1962 | RDSH |
8.50 | PE | Chizhov, Timoshenko, et al., 1986 | Vertical value; LBLHLM |
8.52 | PE | Kobayashi, Yokota, et al., 1973 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C9H9+ | 11.8 ± 0.1 | H | EI | Koppel, Schwarz, et al., 1974 | LLK |
De-protonation reactions
C9H9- + =
By formula: C9H9- + H+ = C9H10
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1613. ± 23. | kJ/mol | G+TS | Bartmess and Burnham, 1984 | gas phase; between H2O, MeOH; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1586. ± 23. | kJ/mol | IMRB | Bartmess and Burnham, 1984 | gas phase; between H2O, MeOH; B |
References
Go To: Top, Phase change data, Gas phase ion energetics data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Anonymous, 1952
Anonymous, R.,
, Physical Properties of Chemical Substances, Dow Chemical Co., 1952. [all data]
Anonymous, 1946
Anonymous, R.,
, Am. Pet. Inst. Res. Proj. 45, Ohio State Univ., 1946. [all data]
Stull, 1945
Stull, D.R.,
Personal Commun., Dow Chemical Co., 1945. [all data]
Anonymous, 1943
Anonymous, R.,
, Sunbury Rep. No. 2176, Anglo-Iranian Oil Co., 1943. [all data]
Steele, Chirico, et al., 1997
Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.,
Vapor Pressure, Heat Capacity, and Density along the Saturated Line, Measurements for Dimethyl Isophthalate, Dimethyl Carbonate, 1,3,5-Trimethyl benzene, Pentafluorophenol, 4-tert-Butylcatechol, .alp,
J. Chem. Eng. Data, 1997, 42, 1008-20. [all data]
Verevkin, 1999
Verevkin, Sergey P.,
Thermochemical investigation on α-methyl-styrene and parent phenyl substituted alkenes,
Thermochimica Acta, 1999, 326, 1-2, 17-25, https://doi.org/10.1016/S0040-6031(98)00585-1
. [all data]
Steele, Chirico, et al., 1997, 2
Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.,
Vapor Pressure, Heat Capacity, and Density along the Saturation Line, Measurements for Dimethyl Isophthalate, Dimethyl Carbonate, 1,3,5-Triethylbenzene, Pentafluorophenol, 4- tert -Butylcatechol, α-Methylstyrene, and N , N '-Bis(2-hydroxyethyl)ethylenediamine,
J. Chem. Eng. Data, 1997, 42, 6, 1008-1020, https://doi.org/10.1021/je970102d
. [all data]
Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw,
Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2
. [all data]
Stull, 1947
Stull, Daniel R.,
Vapor Pressure of Pure Substances. Organic and Inorganic Compounds,
Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022
. [all data]
Lebedev and Rabinovich, 1971
Lebedev, B.V.; Rabinovich, I.B.,
Heat capacities and thermodynamic functions of a-methylstyrene and poly(a-methylstyrene),
Tr. Khim. Khim. Tekhnol., 1971, 1, 12-15. [all data]
Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D.,
Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III,
J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985
. [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]
Koppel, Schwarz, et al., 1974
Koppel, C.; Schwarz, H.; Bohlmann, F.,
Elektronenstossinduzierte fragmentierung von acetylenverbindungen. VIII. Struktur der stabilen und instabilen ionen[C9H9]+ aus isomeren C9H10- kohlenwasserstoffen,
Org. Mass Spectrom., 1974, 8, 25. [all data]
Benito, Seidl, et al., 1973
Benito, I.; Seidl, H.; Bock, H.,
Efectos electronicos y estericos de sustituyentes alquilicos y silicicos sobre el sistema electronico π del estireno,
Rev. Fac. Cienc. Univ. Oviedo, 1973, 14, 95. [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]
Chizhov, Timoshenko, et al., 1986
Chizhov, Y.V.; Timoshenko, M.M.; Kleimenov, V.I.; Borisov, Y.A.; Zol'nikova, G.P.; Kravtsov, D.N.; Kritskaya, I.I.,
Investigation of the mechanism of fragment coordination of aromatic molecules with transition metals by photoelectron spectroscopy - tricarbonyliron complexes,
J. Struct. Chem., 1986, 27, 401. [all data]
Kobayashi, Yokota, et al., 1973
Kobayashi, T.; Yokota, K.; Nagakura, S.,
Photoelectron spectra of styrenes,
J. Electron Spectrosc. Relat. Phenom., 1973, 3, 449. [all data]
Bartmess and Burnham, 1984
Bartmess, J.E.; Burnham, R.,
Effect of central substituents on the gas phase acidities of propenes,
J. Org. Chem., 1984, 49, 1382. [all data]
Notes
Go To: Top, Phase change data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy Pc Critical pressure Tboil Boiling point Tc Critical temperature Tfus Fusion (melting) point ΔfusH Enthalpy of fusion ΔfusS Entropy of fusion ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔvapH Enthalpy of vaporization ΔvapH° Enthalpy of vaporization at standard conditions ρc Critical density - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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