2-Butyne
- Formula: C4H6
- Molecular weight: 54.0904
- IUPAC Standard InChI: InChI=1S/C4H6/c1-3-4-2/h1-2H3
- IUPAC Standard InChIKey: XNMQEEKYCVKGBD-UHFFFAOYSA-N
- CAS Registry Number: 503-17-3
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript. - Other names: But-2-yne; Dimethylacetylene; CH3C≡CCH3; Crotonylene; UN 1144
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Vibrational and/or electronic energy levels
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Takehiko Shimanouchi
Symmetry: D'3h Symmetry Number σ = 6
| Sym. | No | Approximate | Selected Freq. | Infrared | Raman | Comments | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Species | type of mode | Value | Rating | Value | Phase | Value | Phase | |||
| a'1 | 1 | CH3 s-str | 2916 | C | ia | 2916 S p | liq. | Free rotation | ||
| a'1 | 2 | C≡C str | 2240 | E | ia | 2310 S p | liq. | Free rotation, FR(2ν8) | ||
| a'1 | 2 | C≡C str | 2240 | E | ia | 2233 S p | liq. | Free rotation, FR(2ν8) | ||
| a'1 | 3 | CH3 s-deform | 1380 | C | ia | 1380 S | liq. | Free rotation | ||
| a'1 | 4 | C-C str | 725 | E | ia | 774 M p | liq. | Free rotation, FR(2ν16) | ||
| a'1 | 4 | C-C str | 725 | E | ia | 693 M p | liq. | Free rotation, FR(2ν16) | ||
| a"1 | 5 | CH3 torsion | ia | ia | Free rotation | |||||
| a"2 | 6 | CH3 s-str | 2938 | B | 2938 S | gas | ia | Free rotation | ||
| a"2 | 7 | CH3 s-deform | 1382 | B | 1382 M | gas | ia | Free rotation | ||
| a"2 | 8 | C-C str | 1152 | B | 1152 W | gas | ia | Free rotation | ||
| e' | 9 | CH3 d-str | 2973 | B | 2973 S | gas | Free rotation | |||
| e' | 10 | CH3 d-deform | 1456 | B | 1456 S | gas | Free rotation | |||
| e' | 11 | CH3 rock | 1054 | B | 1054 M | gas | Free rotation | |||
| e' | 12 | CCC deform | 213 | C | 213 VW | liq. | Free rotation | |||
| e | 13 | CH3 d-str | 2966 | D | ia | 2966 W | liq. | Free rotation | ||
| e | 14 | CH3 d-deform | 1448 | C | ia | 1448 M dp | liq. | Free rotation | ||
| e | 15 | CH3 rock | 1029 | C | ia | 1029 M dp | liq. | Free rotation | ||
| e | 16 | CCC deform | 371 | C | ia | 371 S dp | liq. | Free rotation | ||
Source: Shimanouchi, 1972
Notes
| S | Strong |
| M | Medium |
| W | Weak |
| VW | Very weak |
| ia | Inactive |
| p | Polarized |
| dp | Depolarized |
| FR | Fermi resonance with an overtone or a combination tone indicated in the parentheses. |
| B | 1~3 cm-1 uncertainty |
| C | 3~6 cm-1 uncertainty |
| D | 6~15 cm-1 uncertainty |
| E | 15~30 cm-1 uncertainty |
References
Go To: Top, Vibrational and/or electronic energy levels, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Shimanouchi, 1972
Shimanouchi, T.,
Tables of Molecular Vibrational Frequencies Consolidated Volume I, National Bureau of Standards, 1972, 1-160. [all data]
Notes
Go To: Top, Vibrational and/or electronic energy levels, References
- Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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