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Experimental data for C5H10 (1-Butene, 2-methyl-)

22 02 02 11 45
Other names
γ-Isoamylene; 1-Butene, 2-methyl-; 1-Isoamylene; 2-Methyl-1-butene; 2-Methylbutene-1; Isopentene; gamma-Isoamylene; 2-methylbut-1-ene;
INChI INChIKey SMILES IUPAC name
InChI=1S/C5H10/c1-4-5(2)3/h2,4H2,1,3H3 MHNNAWXXUZQSNM-UHFFFAOYSA-N C=C(C)CC 2-methylbut-1-ene
State Conformation
1A C1
Enthalpy of formation (Hfg), Entropy, Integrated heat capacity (0 K to 298.15 K) (HH), Heat Capacity (Cp)
Property Value Uncertainty units Reference Comment
Hfg(298.15K) enthalpy of formation -34.90   kJ mol-1 TRC
Hfg(0K) enthalpy of formation -8.20   kJ mol-1 TRC
Entropy (298.15K) entropy 339.60   J K-1 mol-1 TRC
Integrated Heat Capacity (0 to 298.15K) integrated heat capacity 20.86   kJ mol-1 TRC
Heat Capacity (298.15K) heat capacity 109.96   J K-1 mol-1 webbook
Information can also be found for this species in the NIST Chemistry Webbook
Vibrational levels (cm-1) vibrations
Mode Number Symmetry Frequency Intensity Comment Description
Fundamental(cm-1) Harmonic(cm-1) Reference (km mol-1) unc. Reference
1 A' 3084   1993Cro:1923      
2 A' 2994   1993Cro:1923      
3 A' 2986   1993Cro:1923      
4 A' 2976   1993Cro:1923       renumbered for comparisons
5 A' 2945   1993Cro:1923       renumbered for comparisons
6 A' 2943   1993Cro:1923       renumbered for comparisons
7 A' 2880   1993Cro:1923       renumbered for comparisons
8 A' 1644   1993Cro:1923       renumbered for comparisons
9 A' 1467   1993Cro:1923       renumbered for comparisons
10 A' 1458   1993Cro:1923       renumbered for comparisons
11 A' 1447   1993Cro:1923       renumbered for comparisons
12 A' 1414   1993Cro:1923       renumbered for comparisons
13 A' 1379   1993Cro:1923       renumbered for comparisons
14 A' 1371   1993Cro:1923       renumbered for comparisons
15 A' 1329   1993Cro:1923       renumbered for comparisons
16 A' 1249   1993Cro:1923       renumbered for comparisons
17 A' 1089   1993Cro:1923       renumbered for comparisons
18 A' 1017   1993Cro:1923       renumbered for comparisons
19 A' 996   1993Cro:1923       renumbered for comparisons
20 A' 938   1993Cro:1923       renumbered for comparisons
21 A' 772   1993Cro:1923       renumbered for comparisons
22 A' 495   1993Cro:1923       renumbered for comparisons
23 A' 400   1993Cro:1923       renumbered for comparisons
24 A' 285   1993Cro:1923       renumbered for comparisons
25 A" 2984   1993Cro:1923       renumbered for comparisons
26 A" 2976   1993Cro:1923       renumbered for comparisons
27 A" 2900   1993Cro:1923       renumbered for comparisons
28 A" 1462   1993Cro:1923       renumbered for comparisons
29 A" 1460   1993Cro:1923       renumbered for comparisons
30 A" 1255   1993Cro:1923       renumbered for comparisons
31 A" 1082   1993Cro:1923       renumbered for comparisons
32 A" 1017   1993Cro:1923       renumbered for comparisons
33 A" 890   1993Cro:1923       renumbered for comparisons
34 A" 790   1993Cro:1923       renumbered for comparisons
35 A" 677   1993Cro:1923       renumbered for comparisons
36 A" 434   1993Cro:1923       renumbered for comparisons
37 A" 257   1993Cro:1923      
38 A" 170   1993Cro:1923      
39 A" 119   1993Cro:1923      

vibrational zero-point energy: 29015.5 cm-1 (from fundamental vibrations)
Calculated vibrational frequencies for C5H10 (1-Butene, 2-methyl-).
Gas-phase IR spectra can be found in the NIST Chemistry Webbook here.
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
       

Calculated rotational constants for C5H10 (1-Butene, 2-methyl-).
Product of moments of inertia moments of inertia
amu3Å6   0gm3 cm6
Geometric Data
picture of 1-Butene, 2-methyl-

Point Group C1


Internal coordinates
distances (r) in Å, angles (a) in degrees, dihedrals (d) in degrees
Description Value unc. Connectivity Reference Comment
Atom 1 Atom 2 Atom 3 Atom 4
aCCC 125.2 9 12 13 1976Hellwege(II/7) to ethyl
aCCC 122.5 1 12 13 1976Hellwege(II/7) to methyl
aCCC 116 5 9 12 1976Hellwege(II/7) ethyl

Cartesians
Atom x (Å) y (Å) z (Å)

Atom - Atom Distances bond lengths
Distances in Å
 

Calculated geometries for C5H10 (1-Butene, 2-methyl-).

Bond descriptions


Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
H-C 10
C-C 3
C=C 1

Connectivity
Atom 1 Atom 2
C1 H2
C1 H3
C1 H4
C1 C12
C5 H6
C5 H7
C5 H8
C5 C9
C9 H10
C9 H11
C9 C12
C12 C13
C13 H14
C13 H15
Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 1   1A

Ionization Energies (eV)
Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. reference
9.120 0.010 9.150 0.100 webbook
Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
State Config State description Conf description Exp. min. Dipole (Debye) Reference comment Point Group Components
x y z total dipole quadrupole
1 1 1A C1 True           C1 3 5
Experimental dipole measurement abbreviations: MW microwave; DT Dielectric with Temperature variation; DR Indirect (usually an upper limit); MB Molecular beam
Calculated electric dipole moments for C5H10 (1-Butene, 2-methyl-).
Electric quadrupole moment quadrupole
State Config State description Conf description Exp. min. Quadrupole (D Å) Reference comment Point Group Components
xx yy zz dipole quadrupole
1 1 1A C1 True       C1 3 5

Calculated electric quadrupole moments for C5H10 (1-Butene, 2-methyl-).
References
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squib reference DOI
1976Hellwege(II/7) Hellwege, KH and AM Hellwege (ed.). Landolt-Bornstein: Group II: Atomic and Molecular Physics Volume 7: Structure Data of Free Polyatomic Molecules. Springer-Verlag. Berlin. 1976.  
1993Cro:1923 Crowder. Vibrational and Conformational Analysis of 2-Methyl-1-Butene. Spectroscopy Letters. Vol. 26. #10. Pgs. 1923-1938. 10.1080/00387019308011642
TRC Frenkel, M; Marsh, K.N.; Wilhoit, R.C.; Kabo, G.J.; Roganov, G.N.,Thermodynamics of Organic Compounds in the Gas State,Thermodynamics Research Center, College Station, TX, 1994  
webbook NIST Chemistry Webbook (http://webbook.nist.gov/chemistry) 10.18434/T4D303

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