Ry. Dong et al., ROTATIONAL ANALYSES OF BANDS OF THE (A)OVER-TILDE1B1-(X)OVER-TILDE1A1SYSTEM OF CIS-GLYOXAL, Canadian journal of chemistry, 71(10), 1993, pp. 1595-1597
Rotational analyses have been carried out for the 5(0)1, 5(1)0, and 5(
1)1 bands of the A1B1-X1A1 system of cis-glyoxal, where nu5 is the tot
ally symmetric C-C=O bending frequency. The vibrational frequencies nu
5' = 103.81 cm-1 and nu5'' = 284.51 cm-1 are smaller than the correspo
nding frequencies for trans-glyoxal by nearly a factor of two. A vibro
nically induced band with a different type of rotational structure has
been analysed and shown to be an a-type band. The coupling vibration
is the out-of-plane C-H wagging vibration nu6(a2) and is similar in fo
rm and frequency to the vibronically active nu8(b(g)) vibration for tr
ans-glyoxal.