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Experimental data for C4H6 (1-Methylcyclopropene)

22 02 02 11 45
Other names
1-Methylcyclopropene; Cyclopropene, 1-methyl-; 1-methylcycloprop-1-ene;
INChI INChIKey SMILES IUPAC name
InChI=1S/C4H6/c1-4-2-3-4/h2H,3H2,1H3 SHDPRTQPPWIEJG-UHFFFAOYSA-N CC1=CC1 1-methylcycloprop-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 243.60 1.20 kJ mol-1 1970COX/PIL
Hfg(0K) enthalpy of formation 257.90 1.20 kJ mol-1 1970COX/PIL
Entropy (298.15K) entropy 287.38   J K-1 mol-1 TRC
Integrated Heat Capacity (0 to 298.15K) integrated heat capacity 15.32   kJ mol-1 TRC
Heat Capacity (298.15K) heat capacity 74.68   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' 3133   1969MIt/Mer:1881      
2 A' 3049   1969MIt/Mer:1881      
3 A' 2929   1969MIt/Mer:1881      
4 A' 2895   1969MIt/Mer:1881      
5 A' 1788   1969MIt/Mer:1881      
6 A' 1487   1969MIt/Mer:1881      
7 A' 1450   1969MIt/Mer:1881      
8 A' 1390   1969MIt/Mer:1881      
9 A' 1308   1969MIt/Mer:1881      
10 A' 1059   1969MIt/Mer:1881      
11 A' 1032   1969MIt/Mer:1881      
12 A' 964   1969MIt/Mer:1881      
13 A' 919   1969MIt/Mer:1881      
14 A' 665   1969MIt/Mer:1881      
15 A' 331   1969MIt/Mer:1881      
16 A" 3071   1969MIt/Mer:1881      
17 A" 2973   1969MIt/Mer:1881      
18 A" 1400   1969MIt/Mer:1881      
19 A" 1168   1969MIt/Mer:1881      
20 A" 1097   1969MIt/Mer:1881      
21 A" 950   1969MIt/Mer:1881      
22 A" 696   1969MIt/Mer:1881      
23 A" 283   1969MIt/Mer:1881      
24 A"            

vibrational zero-point energy: 18017.5 cm-1 (from fundamental vibrations)
Calculated vibrational frequencies for C4H6 (1-Methylcyclopropene).
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
0.68547 0.21205 0.17267  

Calculated rotational constants for C4H6 (1-Methylcyclopropene).
Product of moments of inertia moments of inertia
190876.3amu3Å6   8.74017218854313E-115gm3 cm6
Geometric Data
picture of 1-Methylcyclopropene

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
rCH 1.070   1 2 1976Hellwege(II/7) !assumed
rCC 1.515   2 6 1976Hellwege(II/7) !assumed, opp extra C
rCC 1.300   2 3 1976Hellwege(II/7) !assumed
rCH 1.087   4 6 1976Hellwege(II/7) !assumed, C with 2 H
rCH 1.087   5 6 1976Hellwege(II/7) !assumed, C with 2 H
rCH 1.085   7 10 1976Hellwege(II/7) !assumed, C outside ring
rCH 1.098   8 10 1976Hellwege(II/7) !assumed, C outside ring
rCH 1.098   9 10 1976Hellwege(II/7) !assumed, C outside ring
rCC 1.476   3 6 1976Hellwege(II/7)
aHCC 150 1 2 3 1976Hellwege(II/7) !assumed
aHCH 114.7 4 6 5 1976Hellwege(II/7) !assumed, C with 2 H
aCCC 50.8 2 5 3 1976Hellwege(II/7) !assumed, C with 2 H in middle
aHCC 111 3 10 7 1976Hellwege(II/7) !assumed, to methyl
aCCC 152.8 2 3 10 1976Hellwege(II/7) to methyl C
aHCH 109 7 10 8 1976Hellwege(II/7) !assumed, C outside ring
aHCH 109 8 10 9 1976Hellwege(II/7) !assumed, C outside ring

These cartesians were determined using some assumed coordinate values. Cartesians
Atom x (Å) y (Å) z (Å)

Atom - Atom Distances bond lengths
Distances in Å
 

Calculated geometries for C4H6 (1-Methylcyclopropene).

Bond descriptions


Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
H-C 6
C-C 3
C=C 1

Connectivity
Atom 1 Atom 2
H1 C2
C2 C3
C2 C6
C3 C6
C3 C10
H4 C6
H5 C6
H7 C10
H8 C10
H9 C10
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
9.430 0.020 9.430 0.030 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       0.840 NISThydrocarbon μa = 0.818(8), μb= 0.19(2) 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 C4H6 (1-Methylcyclopropene).
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 C4H6 (1-Methylcyclopropene).

References
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squib reference DOI
1969MIt/Mer:1881 Mitchell and Merritt. Infrared and Raman spectra of 1-methylcyclopropene. Spectrochimica Acta. Vol. 25A. pgs. 1881-1889. 10.1016/0584-8539(69)80219-9
1970COX/PIL J.D. Cox, G. Pilcher, "Thermochemistry of Organic and Organometallic Compounds" Academic Press, London, 1970 10.1002/bbpc.19700740727
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.  
NISThydrocarbon NIST Hydrocarbon spectral database (http://www.physics.nist.gov/PhysRefData/MolSpec/Hydro/index.html) 10.18434/T4PC70
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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