Unusual Anharmonicities in Isomerizing Systems: the S1 State of C2H2 Conference Paper uri icon


  • Abstract Low-barrier {cis}-{trans} isomerization profoundly affects the tilde {A}-tilde {X} spectrum of acetylene. We present extensions of the usual effective Hamiltonian model that capture these effects, and thereby enable fits of the complete tilde {A}{} 1 A u state J= K= 0 level structure up to 4300 cm-1 above the {trans} zero point level. The relationship between these new additions to the model and spectroscopic indicators of the transition state energy will also be discussed. One dimensional models will be used to illustrate both the effects of the isomerization dynamics on the spectrum and how they can be exploited to reveal the isomerization barrier height.

publication date

  • June 1, 2012