Knowledge Bank

Color center laser spectroscopy has been applied to direct absorption observation of the $\nu 1$ band of DCN-HCN generated in a pulsed supersonic jet expansion. A new wavenumber scanning system has been used for the observation, where a laser end mirror and an internal etalon have locked to a fringe of an external scanning etalon and the wavenumber was swept by scanning the external etralon. The 15 lines were assigned to the $\nu 1$ band of DCN-HCN, In order to obtain precise molecular constants, we have measured direct absorption millimeter wave spectra of deuterated species of HCN dimer in the ground state. A simultaneous analysis of the infrared and millimeter wave spectra yielded the band origin and rotational constants of DCN-HCN as $\nu 1=3241.60809(93)cm-1,B1=1666.66(47)MHz$, and $B0=1662.4350(35)MHz$.