Transient grating study of the intermolecular dynamics of liquid nitrobenzene

Abstract

Femtosecond time-resolved transient grating (TG) technique is used to study the intermolecular dynamics in liquid phase. Non-resonant excitation of the sample by two crossing laser pulses results in a transient Kerr grating, and the molecular motion of liquid can be detected by monitoring the diffraction of a third time-delayed probe pulse. In liquid nitrobenzene (NB), three intermolecular processes are observed with lifetimes of 37.9±1.4 ps, 3.28±0.11 ps, and 0.44±0.03 ps, respectively. These relaxations are assigned to molecular orientational diffusion, dipole/induced dipole interaction, and libration in liquid cage, respectively. Such a result is slightly different from that obtained from OKE experiment in which the lifetime of the intermediate process is measured to be 1.9 ps. The effects of electric field on matter are different in TG and optical Kerr effect (OKE) experiments, which should be responsible for the difference between the results of these two types of experiments. The present work demonstrates that TG technique is a useful alternative in the study of intermolecular dynamics.

Spin polarization and dispersion effects in emergence of roaming transition state for nitrobenzene isomerization

“…Nitrobenzene is one of the typical energetic materials whose geometries and spectrum properties, isomerization and even dissociation channels have been studied theoretically and experimentally [14][15][16][17][18][19] . Recently, a new reaction channel in the …”

“…Nitrobenzene is one of the typical energetic materials whose geometries and spectrum properties, isomerizations and even dissociation channels have been studied theoretically and experimentally. [14][15][16][17][18][19] Recently, a new reaction channel in the photodissociation process of nitrobenzene was reported, suggesting a unimolecular isomerization process through a typical TS R . [20] So far, most of the previous researches have focused on the dynamic properties of the roaming systems, with certain atoms or functional groups roaming around the rest part and then dissociated or isomerized.…”

“…Nitrobenzene is one of the typical energetic materials whose geometries and spectrum properties, isomerization and even dissociation channels have been studied theoretically and experimentally [14][15][16][17][18][19] . Recently, a new reaction channel in the photodissociation process of nitrobenzene was reported, suggesting a unimolecular isomerization process through a typical TSR [20] .…”