return to home page

II.A.3. (XII.A.1.)

Listing of experimental geometry data for C2H3CCH (1-Buten-3-yne)

Rotational Constants (cm-1)
See section I.F.4 to change rotational constant units
1.67754 0.15827 0.14442
Rotational Constants from NISThydrocarbon
Calculated rotational constants for C2H3CCH (1-Buten-3-yne).

Point Group Cs

Internal coordinates (distances (r) in Å) (angles (a) in degrees) (dihedrals (d) in degrees)
Description Value Connectivity Reference Comment
Atom 1 Atom 2 Atom 3 Atom 4
rCC 1.434 1 2 1976Hellwege(II/7)
rCC 1.344 1 3 1976Hellwege(II/7)
rCC 1.215 2 4 1976Hellwege(II/7)
rCH 1.106 3 6 1976Hellwege(II/7) average of vinyl CH bond lengths
rCH 1.090 4 8 1976Hellwege(II/7)
aCCC 123.1 2 1 3 1976Hellwege(II/7)
aCCC 177.9 1 2 4 1976Hellwege(II/7)
aHCC 118.7 1 3 6 1976Hellwege(II/7)
aHCC 121.6 1 3 7 1976Hellwege(II/7)
aHCC 121.7 3 1 5 1976Hellwege(II/7)
aHCC 182.3 2 4 8 1976Hellwege(II/7)
picture of 1-Buten-3-yne

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=C 1
C#C 1
H-C 2

Atom x (Å) y (Å) z (Å)

Atom - Atom Distances (Å)

Calculated geometries for C2H3CCH (1-Buten-3-yne).

By selecting the following links, you may be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to
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.  
NISThydrocarbon NIST Hydrocarbon spectral database (  

Got a better number? Please email us at