Diode laser absorption spectra of H12C13CD and H13C12CD at 6500 cm−1

The absorption spectra of H12C13CD and H13C12CD have been observed at high resolution between 6480 and 6610 cm−1 using an external cavity diode laser. The strong 2ν1 band has been observed for each species using a sample enriched in deuterium at natural abundance of 13C. Rotational analyses reveal bands of both species to be essentially unperturbed. Centers of unblended lines are determined with an accuracy of approximately 10 MHz.