High-resolution infrared study of Coriolis resonances in the ν9 and ν10 bands of allene-d4

The infrared spectrum of the 2ν9, ν9+ν10, 2ν10 band system in allene-d4

“…For K=0 the Coriolis interactions vanish in the matrix (4). In this case, the vibrational resonance of equation (3) produces vibrational l type doubling in the overtone levels.…”

“…The first order z Coriolis resonance between the fundamental levels v 9 and I"10 has been dealt with in [4]. This interaction is diagonal in the quantum numbers J and K ,and in the sum 19+ l~0.…”

“…This means, that for given J and K the Coriolis resonance is between the rovibrational levels in each of the triads (2v9+2, v9+1+ rio +1, 2Vlo +2) and (2v9 -2, v9-1+ Vlo -1, 2Vlo-2). Denoting the usual symmetric top rovibrational wavefunctions by 12v9+2; J, K), Ivg-+t+Vlo±l; J, K) and [2v,o ±2 ; J, K), the interaction matrix elements are given by [4] <2v9~2 ; J, gl/-'/llvg+xq -1/10 +1 ; J~ K) =<2V,o±2; J,K[I~llV9±l+vlo±l; J,K)=gW9,aoK (1) where the parameter W9,10 depends on the interaction zeta constant in the following way O~ 9 ~-OJlO .…”

“…Recent high resolution infrared studies of allene-d 4 in the frequency region above 1900 cm -1 [1,2] and the region below 1100 cm -1 [3][4][5] have resulted in a set of accurate ground state constants, as well as upper state constants for most of the infrared active fundamental levels of this molecule.…”

“…The present study is restricted to a discussion of the 2v9, Vg+ Vl0 and 2vl0 bands. These bands are strongly perturbed by a first order z Coriolis resonance which corresponds to the interaction between the fundamental bands v 9 and vl0 [4].…”