Abstract
The air-liquid interface and the liquid-phase of benzene, toluene, 1,3-dimethylbenzene, and 1,3,5-trimethylbenzene are studied using broad bandwidth sum frequency generation spectroscopy, Raman and infrared spectroscopy. A vibrationally resonant sum frequency response is observed from these surfaces in spite of the small hyperpolarizabilities, in particular, the zero and near-zero hyperpolarizabilities of benzene and 1,3,5-trimethylbenzene. The orientation of the aromatic rings of these compounds at their air-liquid interfaces is tilted relative to the surface plane. Thus, on average, the plane of the aromatic ring does not lie in the interfacial plane. Comparison of the square root of the sum frequency intensity to that of the Raman multiplied bythe infrared intensity provides additional information about the molecular environment at their respective air-liquid interface.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
