Detection of the infrared spectrum of CH2+

A Theoretical Study of ã4A2 CH2+

“…Despite all this theoretical activity the only gas phase spectrum of the ion that has been obtained so far is that of the ν 3 antisymmetric CH stretching fundamental band at 3131 cm −1 (8). The theoretical work has provided benchmark predictions that have been crucial in allowing a recent carefully interpreted Coulomb explosion image to be validated, and the latest results (9) are in very satisfactory agreement with the theoretical predictions.…”

“…If the molecular states are degenerate, that is, if there is more than one eigenfunction int (or int ) corresponding to the eigenvalue E (or E ), we calculate the linestrength by adding the individual transition probabilities for all transitions between the degenerate states; this is indicated by the sum over int and int in Eq. [8]. (22)).…”

The Matrix Isolation Spectrum of the CH2+ Ion

“…(2,(7)(8)(9)(10)(11) we present our results concerning the ab initio calculation of the potential energy, dipole moment, and transition moment surfaces for CH + 2 ; we also describe the method used to calculate the term values and spectral intensities, and we simulate spectra of CH + 2 and CD + 2 ions at 200 K. In the present paper we simulate the infrared spectrum for ions 1 This paper is dedicated to Professor Hans Bürger on the occasion of his 65th birthday. at a temperature of 5 K, and this is relevant for predicting the appearance of the matrix isolation infrared spectrum.…”

“…The spectroscopic characterization of the CH + 2 molecular ion in the gas phase has only been achieved so far in the ν 3 (antisymmetric CH stretching) fundamental band (1). From ab initio calculation it is predicted that theX 2 A 1 ground state is quasilinear and degenerate at linearity with the excitedà 2 B 1 state (2).…”

High‐resolution Photoelectron Spectroscopy

“…Microwave, infrared and electronic spectroscopy have been exceptionally successful in providing spectroscopic information on fundamentally important cations such as H + 3 (Oka and Jagod 1993), CH + 2 (Rösslein et al 1992), CH + 3 (Crofton et al 1985), CH + 5 (White et al 1999) and H 3 O + (Begemann et al 1983), to list but a few. Other important cations, such as H + 2 , He + 2 , or CH + 4 have been difficult to study with these methods, and, so far, could only be investigated at highresolution by photoelectron spectroscopy and related methods (Osterwalder et al 2004b, Raunhardt et al 2008, Signorell and Merkt 2000, Wörner and Merkt 2009.…”