In database:

100-310 nm

Butadiyne (C₄H₂) (diacetylene)
Molecular weight 50.06 amu
Freezing point C
Boiling point: 11 C

UV cross-sections
From David Crisp, .1-.31 microns.
Images of UV data

Please see The MPI-Mainz UV/VIS Spectral Atlas

Additional references
Computational resolution enhancement: congested overtone spectrum of diacetylene, Metsala et al., Mol. Phys 101:629-635 (2003)
Figure 1 showing infrared spectra from 6350 to 6750 cm^-1.

Absolute IR Band intensities of Diacetylene in the 250-4300 cm^-1 Region: Implications for Titan's Atmosphere, Khlifi et al.,J.Mol.Spec. 174:116-122 (1995).
Figure 1 showing infrared spectrum from 400 to 4000 cm^-1.

The Ultraviolet Photochemistry of Diacetylene: Direct Detection of Primary Products of the Metastable C₄H₂^* + C₄H₂ Reaction; R.E. Bandy et al.; J.Chem.Phys. 98:5362-5374 (1993).
Figure 2 showing two-photon ionization spectrum from 41000 to 46000 cm^-1.

Notes
Fundamental frequencies from NIST Chemistry Webbook
n₁ 3293 cm^-1 (S_g⁺) CH stretch
n₂ 2184 cm^-1 (S_g⁺) CC stretch
n₃ 874 cm^-1 (S_g⁺) CC stretch
n₄ 3329 cm^-1 (S_u⁺) CH stretch
n₅ 2020 cm^-1 (S_u⁺) CC stretch
n₆ 627 cm^-1 (p_g) CH bend
n₇ 482 cm^-1 (p_g) CCC bend
n₈ 630 cm^-1 (p_u) CH bend
n₉ 231 cm^-1 (p_u) CCC bend



List of available data for all molecules in database
Return to front page