Optical Heterodyne-detected Raman-induced Kerr Effect Spectroscopy Research Articles

Deuterium Isotope Effects on the Ultrafast Solvent Relaxation of Formamide and N,N-Dimethylformamide

We present the results of our study on the ultrafast solvent dynamics of the amides formamide (FA), N-dimethylformamide (DMF), and their deuterated analogs HCOND[sub 2] (d[sub 2]-FA) and DCON(CD[sub 3])[sub 2] (d[sub 7]-DMF) us femtosecond optical-heterodyne-detected Raman-induced Kerr effect spectroscopy (OHD-RIKES). As nearly transform-limited 50 fs optical pulses and the Fourier-transform relationship, we have studied liquid dynamics in the frequency range from 0.6 to 400 cm[sup [minus]1]. In comparison to the depolarized Rayle spectroscopy technique. OHD-RIKES is shown to provide more accurate and detailed information about low-frequency region that includes the rotational reorientation, librational and collision-induced dynamic. The effect of deuterium isotope substitution on the inertial as well as diffusive reorientational dynamics these amide liquids is discussed. 91 refs., 9 figs., 4 tabs.