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Experimental data for HCCBr (bromoacetylene)

22 02 02 11 45
Other names
Acetylene, bromo-;
State Conformation
1Σ C*V
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 269.00 6.30 kJ mol-1 webbook
Hfg(0K) enthalpy of formation   6.30 kJ 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 Σ 3325   webbook      
2 Σ 2085          
3 Σ 618          
4 Π 618          
5 Π 295          

vibrational zero-point energy: 3927.0 cm-1 (from fundamental vibrations)
Calculated vibrational frequencies for HCCBr (bromoacetylene).
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
  0.13343   1977Jon/She:866

Calculated rotational constants for HCCBr (bromoacetylene).
Product of moments of inertia moments of inertia
126.3422amu Å2   2.097995E-38gm cm2
Geometric Data
picture of bromoacetylene

Point Group C∞v

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 1.204 0.005 1 2 1987Kuchitsu(II/15)
rCBr 1.792 0.003 2 3 1987Kuchitsu(II/15)
rCH 1.055 0.005 1 4 1987Kuchitsu(II/15)

Atom x (Å) y (Å) z (Å)
C1 0.0000 0.0000 0.0000
C2 0.0000 0.0000 1.2038
Br3 0.0000 0.0000 2.9954
H4 0.0000 0.0000 -1.0552

Atom - Atom Distances bond lengths
Distances in Å
  C1 C2 Br3 H4
C1   1.20382.99541.0552
C2 1.2038   1.79162.2590
Br3 2.99541.7916   4.0506
H4 1.05522.25904.0506  

Calculated geometries for HCCBr (bromoacetylene).

Experimental Bond Angles (degrees) from cartesians bond angles

atom1 atom2 atom3 angle         atom1 atom2 atom3 angle
C1 C2 Br3 180.000 C2 C1 H4 180.000

Bond descriptions

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

Atom 1 Atom 2
C1 C2
C1 H4
C2 Br3
Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 1   1Σ

Ionization Energies (eV)
Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. reference
10.310 0.020     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 1Σ C∞v True 0.000 0.000 0.230 0.230 1977Jon/She:866 MW +-0.01D μ0 C∞v 1 1
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 HCCBr (bromoacetylene).
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 1Σ C∞v True       C∞v 1 1

Calculated electric quadrupole moments for HCCBr (bromoacetylene).

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squib reference DOI
1977Jon/She:866 H. Jones, J. Sheridan, O. L. Stiefvater "The Micro wave Spectrum of Bromoacetylene ; rs-Structure , Dipole Moment, Quadrupole Coupling Constants and Excited Vibration States" Zeitschrift für Naturforschung A. Volume 32, Issue 8, Pages 866–875 10.1515/zna-1977-0811
1987Kuchitsu(II/15) Kuchitsu (ed.), Landolt-Bornstein: Group II: Atomic and Molecular Physics Volume 15: Structure Data of Free Polyatomic Molecules. Springer-Verlag, Berlin, 1987.  
webbook NIST Chemistry Webbook ( 10.18434/T4D303

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