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Experimental data for C6H12 (2,3-dimethyl-but-2-ene)

22 02 02 11 45
Other names
1,1,2,2-Tetramethylethylene; 2,3-Dimethyl-2-butene; 2,3-Dimethylbut-2-ene; 2,3-Dimethylbutene-2; 2-Butene, 2,3-dimethyl-; Tetramethylethene; Tetramethylethylene;
INChI INChIKey SMILES IUPAC name
InChI=1S/C6H12/c1-5(2)6(3)4/h1-4H3 WGLLSSPDPJPLOR-UHFFFAOYSA-N CC(C)=C(C)C 2,3-Dimethylbut-2-ene
State Conformation
1A D2
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 -70.29 1.51 kJ mol-1 webbook
Hfg(0K) enthalpy of formation   1.51 kJ mol-1 webbook
Entropy (298.15K) entropy     J K-1 mol-1  
Integrated Heat Capacity (0 to 298.15K) integrated heat capacity     kJ mol-1  
Heat Capacity (298.15K) heat capacity 123.60   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 Ag 2999   1974sve/kov      
2 Ag 2862   1974sve/kov      
3 Ag 1683   1974sve/kov      
4 Ag 1456   1974sve/kov      
5 Ag 1397   1974sve/kov      
6 Ag 1027   1974sve/kov      
7 Ag 690   1974sve/kov      
8 Ag 411   1974sve/kov      
9 Au 2975   1974sve/kov      
10 Au 1464   1974sve/kov      
11 Au 979   1974sve/kov      
12 Au 182   1974sve/kov      
13 Au            
14 B1g 2999   1974sve/kov      
15 B1g 2900   1974sve/kov      
16 B1g 1456   1974sve/kov      
17 B1g 1374   1974sve/kov      
18 B1g 1269   1974sve/kov      
19 B1g 947   1974sve/kov      
20 B1g 505   1974sve/kov      
21 B1u 2930   1974sve/kov      
22 B1u 1460   1974sve/kov      
23 B1u 1028   1974sve/kov      
24 B1u 267   1974sve/kov      
25 B1u            
26 B2g 2999   1974sve/kov      
27 B2g 1456   1974sve/kov      
28 B2g 1071   1974sve/kov      
29 B2g 411   1974sve/kov      
30 B2g            
31 B2u 3006   1974sve/kov      
32 B2u 2879   1974sve/kov      
33 B2u 1453   1974sve/kov      
34 B2u 1382   1974sve/kov      
35 B2u 1165   1974sve/kov      
36 B2u 972   1974sve/kov      
37 B2u 181   1974sve/kov      
38 B3g 2999   1974sve/kov      
39 B3g 1456   1974sve/kov      
40 B3g 947   1974sve/kov      
41 B3g            
42 B3u 3006   1974sve/kov      
43 B3u 2879   1974sve/kov      
44 B3u 1460   1974sve/kov      
45 B3u 1382   1974sve/kov      
46 B3u 1172   1974sve/kov      
47 B3u 902   1974sve/kov      
48 B3u 394   1974sve/kov      

vibrational zero-point energy: 34416.0 cm-1 (from fundamental vibrations)
Calculated vibrational frequencies for C6H12 (2,3-dimethyl-but-2-ene).
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 C6H12 (2,3-dimethyl-but-2-ene).
Product of moments of inertia moments of inertia
amu3Å6   0gm3 cm6
Geometric Data
picture of 2,3-dimethyl-but-2-ene

Point Group D2


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
rCC 1.353   1 2 1976Hellwege(II/7)
rCC 1.511   1 3 1976Hellwege(II/7)
rCH 1.118   3 7 1976Hellwege(II/7)
aCCC 123.9 1 2 5 1976Hellwege(II/7)
aHCH 107 7 3 11 1976Hellwege(II/7)

Cartesians
Atom x (Å) y (Å) z (Å)

Atom - Atom Distances bond lengths
Distances in Å
 

Calculated geometries for C6H12 (2,3-dimethyl-but-2-ene).

Bond descriptions


Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
H-C 12
C-C 4
C=C 1

Connectivity
Atom 1 Atom 2
C1 C2
C1 C3
C1 C4
C2 C5
C2 C6
C3 H7
C3 H11
C3 H12
C4 H8
C4 H13
C4 H14
C5 H9
C5 H15
C5 H16
C6 H10
C6 H17
C6 H18
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
8.270 0.010 8.300   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 D2 True           D2 0 2
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 C6H12 (2,3-dimethyl-but-2-ene).
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 D2 True       D2 0 2

Calculated electric quadrupole moments for C6H12 (2,3-dimethyl-but-2-ene).
References
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squib reference DOI
1974sve/kov L.M. Sverdlov, M. A. Kovner, E. P. Krainov, "Vibrational Spectra of Polyatomic Molecules" Wiley, New York 1974  
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.  
webbook NIST Chemistry Webbook (http://webbook.nist.gov/chemistry) 10.18434/T4D303

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