1-Heptyne

Formula: C₇H₁₂
Molecular weight: 96.1702
IUPAC Standard InChI: InChI=1S/C7H12/c1-3-5-7-6-4-2/h1H,4-7H2,2H3
IUPAC Standard InChIKey: YVXHZKKCZYLQOP-UHFFFAOYSA-N
CAS Registry Number: 628-71-7
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: Amylacetylene; n-C5H11C≡CH; hept-1-yne
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- Gas Phase Kinetics Database
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Gas phase thermochemistry data

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Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	24.80 ± 0.61	kcal/mol	Chyd	Rogers, Dagdagan, et al., 1979	ALS
Δ_fH°_gas	24.31	kcal/mol	N/A	Moureu and Andre, 1914	Value computed using Δ_fH_liquid° value of 62.8 kj/mol from Moureu and Andre, 1914 and Δ_vapH° value of 38.9 kj/mol from n-alkyne correlation.; DRB

Constant pressure heat capacity of gas

C_p,gas (cal/mol*K)	Temperature (K)	Reference	Comment
13.62	50.	Thermodynamics Research Center, 1997	p=1 bar.; GT
18.69	100.
22.87	150.
26.398	200.
32.048	273.15
34.175	298.15
34.336	300.
43.109	400.
51.231	500.
58.246	600.
64.242	700.
69.391	800.
73.826	900.
77.658	1000.
80.98	1100.
83.82	1200.
86.30	1300.
88.43	1400.
90.30	1500.

Condensed 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°_liquid	24.16 ± 0.96	kcal/mol	Ccb	N/A	recalculated with modern CO2,H2O thermo; estimated uncertainty (NOTE all values in source also have wrong sign); DRB
Δ_fH°_liquid	-15.0	kcal/mol	Ccb	Moureu and Andre, 1914	ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_liquid	-1092.4	kcal/mol	Ccb	Moureu and Andre, 1914	Corresponding Δ_fHº_liquid = 24.2 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS

Gas phase ion energetics data

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

View reactions leading to C₇H₁₂⁺ (ion structure unspecified)

Ionization energy determinations

IE (eV)	Method	Reference	Comment
10.044 ± 0.005	PE	Carlier, Dubois, et al., 1975	LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
C₅H₇⁺	10.1	C₂H₅	EI	Wagner-Redeker, Levsen, et al., 1981	LLK
C₆H₉⁺	9.9	CH₃	EI	Wagner-Redeker, Levsen, et al., 1981	LLK

References

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

Rogers, Dagdagan, et al., 1979
Rogers, D.W.; Dagdagan, O.A.; Allinger, N.L., Heats of hydrogenation and formation of linear alkynes and a molecular mechanics interpretation, J. Am. Chem. Soc., 1979, 101, 671-676. [all data]

Moureu and Andre, 1914
Moureu, C.; Andre, E., Thermochimie des composes acetyleniques, Ann. Chim. Phys., 1914, 1, 113-145. [all data]

Thermodynamics Research Center, 1997
Thermodynamics Research Center, Selected Values of Properties of Chemical Compounds., Thermodynamics Research Center, Texas A&M University, College Station, Texas, 1997. [all data]

Carlier, Dubois, et al., 1975
Carlier, P.; Dubois, J.E.; Masclet, P.; Mouvier, G., Spectres de photoelectrons des alcynes, J. Electron Spectrosc. Relat. Phenom., 1975, 7, 55. [all data]

Wagner-Redeker, Levsen, et al., 1981
Wagner-Redeker, W.; Levsen, K.; Schwarz, H.; Zummack, W., Gaseous alkyne ions, J. Am. Chem. Soc., 1981, 16, 361. [all data]

Notes

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Symbols used in this document:

AE	Appearance energy
C_p,gas	Constant pressure heat capacity of gas
Δ_cH°_liquid	Enthalpy of combustion of liquid at standard conditions
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_fH°_liquid	Enthalpy of formation of liquid at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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