The First Laboratory Detection of Vibration-rotation Transitions of 12 CH +  and 13 CH +  and Improved Measurement of Their Rotational Transition Frequencies

Abstract

C–H stretches of the fundamental ions CH + and 13 CH + , which have long been searched for, have been observed for the first time in the laboratory. The state-dependent attachment of He atoms to these ions at cryogenic temperatures has been exploited to obtain high-resolution rovibrational data. In addition, the lowest rotational transitions of CH + , 13 CH + and CD + have been revisited and their rest frequency values have improved substantially.