Molecule
- Name
- Ethyne
- IUPAC name
- Ethyne
- Secondary names
- Acetylene, C2H2
- InChI
- InChI=1S/C2H2/c1-2/h1-2H
- InChI key
- HSFWRNGVRCDJHI-UHFFFAOYSA-N
- CAS number
- 74-86-2
- Formula
- $C_2H_2$
- Chemical formula
- C2H2
- Structural formula
- $[CH]#[CH]$
- Charge
- 0
- Relations
-
- no
- Isotope mixture type
- terrestrial abundance
- Spin type
- equilibrated
- Spin quantum numbers
- 0, 1
- Molar mass
- 26.0373 $g/mol$
- State STP
- gas
- Protic
- aprotic
- Polarity
- nonpolar
- Dipole
- 0.0 $D$
- Molecule symmetry
- Dinfh
- Case
- linear-polyatomic
- Vibrations number
- 5
- Vibrations
-
Label Mode Bond Symmetry Degeneracy Fundamental frequency Observed frequency Observed frequency Harmonic frequency Activity IR Activity Raman Strength Comments v1 stretching sym. $\equiv C-H$ no 3373.7 inactive active s v2 stretching sym. $-C\equiv C-$ no 1973.8 inactive active vs v3 stretching asym. $\equiv C-H$ no 3294.9 3281.9 active inactive Fermi resonance with v2+v4+v5 mode v4 bending $>C=C(-)-H$ double 611.8 inactive active vw v5 bending $>C=C(-)-H$ double 730.3 active inactive vs Vibrations of the main isotope: $^{12}C_2H_2$. Data from NIST Chemistry WebBook - Publications