The vibrational dynamics of DCl isolated in nitrogen matrices is investigated by means of time-resolved one-color degenerate four-wave mixing experiments with the help of infrared absorption spectroscopy. Coherence times are found in the tens to hundreds of picoseconds, showing a strong coupling between the DCl stretch and the low-energy local phonons of the lattice. Spectral diffusion due to vibrational energy transfers between the guest molecules is also examined. Fast energy transfers between isotopic species explained the specific shape of the time-resolved signals. The efficiency of such processes is discussed, suggesting an enhancement of the DCl vibrational transition dipole moment induced by the nitrogen environment. (C) 2003 American Institute of Physics.