Vibrational dynamics of CO stretching in W(CO)(6)-doped hybrid xerogels from 5 K to room temperature with the CLIO-FEL

One color pump-probe and photon-echo experiments have been performed on the CO stretching mode of W(CO)(6) at about 1982 cm(-1) in organo-mineral xero gels. Over the whole temperature range studied, from room temperature to 5 K, the population lifetime T-1 remains constant when the vibrational dephas ing time T-2 lengthens slightly. The temperature evolution of the pure deph asing time T-2* reveals two activation energies corresponding to molecular motions of the guest in the xerogel pore. (C) 2000 Elsevier Science B.V. Al l rights reserved.