International journal of mass spectrometry vol:187 pages:131-137
The radiative decays of vibrationally excited DCO+ ions produced by dissociative ionization of CD3CDO have been investigated using the monitor ion technique in a Fourier transform ion cyclotron resonance spectrometer. The radiative lifetimes of the nu(1) (nu = 1, 2) and nu(3) (nu = 1) stretching modes have been determined. For the CO stretching nu(3) the experimental lifetime (24 +/- 2.5 ms) is in good agreement with the theoretical values calculated for DCO+ and HCO+. For the CD stretching nu(1) the experimental lifetimes (112 +/- 22 ms) for nu = 2 and (226 +/- 45 ms) for nu = 1 are about four times larger than the theoretical values, The disagreement between experiment and theory is possibly due to a strong coupling of nu(1) with a long lived state which has not been taken into account in the calculations. For the bending mode nu(2), only a lower limit of the very long lifetime could be evaluated. (Int J Mass Spectrom 185/186/187 (1999) 131-137) (C) 1999 Elsevier Science B.V.