Abstract
Rotationally resolved resonance enhanced multiphoton ionisation spectra of the B^{1}E" state of NH_{2}D are presented and analysed. The analysis indicates a small (34.9 cm^{1}) lifting of the vibronic degeneracy of the zero point level, approximately equal in sign but opposite in magnitude to the splitting observed in NHD_{2} in previous work. This observation is consistent with previous measurements on systems with partial isotopic substitution subject to a mild JahnTeller effect. A model is developed to calculate the splitting induced by asymmetric isotopic substitution of a degenerate electronic state, based on a harmonic force field with linear and quadratic JahnTeller terms added. The force field is developed in internal coordinates to allow the same parameters to be used to calculate the pattern of vibronic levels for all four isotopologues. The lifting of the degeneracy of the zero point level on asymmetric substitution comes from the quadratic JahnTeller effect; the linear term does not lift the degeneracy.
Original language  English 

Pages (fromto)  1414514158 
Number of pages  14 
Journal  Physical Chemistry Chemical Physics 
Volume  21 
Early online date  30 Apr 2015 
DOIs  
Publication status  Published  7 Jun 2015 
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Profiles

Dr Colin M Western
 Spectroscopy and Dynamics
 School of Chemistry  Reader in Chemistry
Person: Academic , Member