Large Amplitude Motions, Especially Isomerization and Tunneling in PolyatomicMolecule Spectra: Novel Experimental, Pattern Recognition, and Theoretical Methods

摘要

Stimulated Emission Pumping (SEP) spectra of HCP imply surprisingly regulardynamics for a rigid molecule undergoing up to 300 deg bending vibrations. Optical Optical Double Resonance (OODR) spectra characterize corresponding (pi* squared reversing pi squared) doubly excited (predissociated) states of HCP and HCCH. The factors governing intensities of nominally forbidden transitions in bent yielding linear SEP spectra are analyzed; this analysis forces the conclusion that transitions into excited CH stretching levels are absent from the A (tilde)-X(tilde) SEP spectra of HCN and HCCH. All mystery transitions in Wodtke's SEP spectra of HCN are assigned. An OODR scheme has been devised for distinguishing electric dipole from magnetic dipole transitions.