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II.A.1. (XV.A.)

Listing of experimental data for C5H8 (1,2-Pentadiene)

Other names
1-Methyl-2,3-butadiene; 1,2-Pentadiene; Ethylallene; pentadiene;
INChI
InChI=1/C5H8/c1-3-5-4-2/h5H,1,4H2,2H3
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 140.70   kJ mol-1 TRC
Hfg(0K) enthalpy of formation 160.50   kJ mol-1 TRC
Entropy (298.15K) entropy 334.90   J K-1 mol-1 TRC
Integrated Heat Capacity (0 to 298.15K) integrated heat capacity 19.35   kJ mol-1 TRC
Heat Capacity (298.15K) heat capacity 101.00   J K-1 mol-1 TRC
Information can also be found for this species in the NIST Chemistry Webbook
Vibrational levels (cm-1) vibrations
Mode Number Symmetry Frequency (cm-1) Frequency Reference Intensity (km mol-1) Int. unc. Intensity Reference Comment
1 A' 3041 1996Dur/Bel:1843      
2 A' 2981 1996Dur/Bel:1843      
3 A' 2963 1996Dur/Bel:1843      
4 A' 2902 1996Dur/Bel:1843      
5 A' 2912 1996Dur/Bel:1843      
6 A' 1965 1996Dur/Bel:1843      
7 A' 1463 1996Dur/Bel:1843      
8 A' 1451 1996Dur/Bel:1843      
9 A' 1442 1996Dur/Bel:1843      
10 A' 1377 1996Dur/Bel:1843      
11 A' 1343 1996Dur/Bel:1843      
12 A' 1309 1996Dur/Bel:1843      
13 A' 1127 1996Dur/Bel:1843      
14 A' 1071 1996Dur/Bel:1843      
15 A' 987 1996Dur/Bel:1843      
16 A' 850 1996Dur/Bel:1843      
17 A' 841 1996Dur/Bel:1843      
18 A' 618 1996Dur/Bel:1843      
19 A' 359 1996Dur/Bel:1843      
20 A' 147 1996Dur/Bel:1843      
21 A" 3054 1996Dur/Bel:1843      
22 A" 2977 1996Dur/Bel:1843      
23 A" 2937 1996Dur/Bel:1843      
24 A" 1463 1996Dur/Bel:1843      
25 A" 1261 1996Dur/Bel:1843      
26 A" 1085 1996Dur/Bel:1843      
27 A" 1002 1996Dur/Bel:1843      
28 A" 875 1996Dur/Bel:1843      
29 A" 781 1996Dur/Bel:1843      
30 A" 530 1996Dur/Bel:1843      
31 A" 340 1996Dur/Bel:1843      
32 A"          
33 A" 103 1996Dur/Bel:1843      

vibrational zero-point energy: 23,778.7 cm-1
Calculated vibrational frequencies for C5H8 (1,2-Pentadiene).
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 C5H8 (1,2-Pentadiene).

Product of moments of inertia moments of inertia
amu3Å6   0gm3 cm6

Geometric Data
picture of 1,2-Pentadiene

Point Group Cs

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

Cartesians
Atom x (Å) y (Å) z (Å)

Atom - Atom Distances bond lengths
Distances in Å
 

Calculated geometries for C5H8 (1,2-Pentadiene).

Bond descriptions
Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
H-C 8
C-C 2
C=C 2

Connectivity
Atom 1 Atom 2
C1 C2
C1 C3
C1 H6
C1 H7
C2 H8
C2 H9
C2 H10
C3 C4
C3 H11
C4 C5
C5 H12
C5 H13

Electronic energy levels (cm-1)
EnergyDegeneracysquib
0 1  

Ionization Energies (eV)
Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. Electron Affinity E.A. unc. reference
9.250 0.020 9.250       webbook

Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
Calculated electric dipole moments for C5H8 (1,2-Pentadiene).
Electric quadrupole moment quadrupole
Calculated electric quadrupole moments for C5H8 (1,2-Pentadiene).
References
squib reference
1996Dur/Bel:1843 Durig, Bell, and Guirgis. Infrared and Raman Spectra, Conformational Stability, ab initio Calculations and Vibrational Assignment for 1,2-pentadiene (ethyl allene). Spectrochimica Acta Part A. Vol. 52. pgs. 1843-1859.
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)

Got a better number? Please email us at cccbdb@nist.gov

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