Complex and sustained quantum beating patterns in a classic IVR system: the 3¹5¹ Level in S₁ p-difluorobenzene

Using picosecond time-resolved photoelectron imaging we have studied the intramolecular vibrational energy redistribution (IVR) dynamics that occur following the excitation of the 3151 level which lies 2068 cm-1 above the S1 origin in p difluorobenzene. Our technique, which has superior time resolution to that of earlier studies but retains sufficient energy resolution to identify the behavior of individual vibrational states, enables us to determine six distinct beating periods in photoelectron intensity, only one of which has been observed previously. Analysis shows that the IVR dynamics are restricted among only a handful of vibrational levels, despite the relatively high excitation energy. This is deduced to be a consequence of the high symmetry and rigid structure of p-difluorobenzene

Probing the origins of vibrational mode specificity in intramolecular dynamics through picosecond time-resolved photoelectron imaging studies

We have studied the intramolecular dynamics induced by selective photoexcitation of two near-isoenergetic vibrational states in S1 p-fluorotoluene using picosecond time-resolved photoelectron imaging. We find that similar dynamics ensue following the preparation of the 13111 and 7a111 states that lie at 1990 cm-1 and 2026 cm-1, and that these dynamics are mediated by a single strongly coupled doorway state in each case. However, the lifetimes differ by a factor of three, suggesting an influence of the vibrational character of the modes involved. Our results clearly show the contribution of torsion-vibration coupling to the dynamics; this is further corroborated by comparison with the 7a111 state in S1 p-difluorobenzene, which lies at 2068 cm-1. We invoke a model in which van der Waals interactions between methyl hydrogen atoms and nearby ring carbon and hydrogen atoms leads to mixing of the vibrational and torsional states. This model predicts that enhanced torsion-vibration coupling occurs when mode 7a is excited, consistent with our observations

International home economics

The conference was planned to serve the interests of those who wish to work in home economics programs abroad and those who are concerned with the education of international students in the universities and colleges of the United States. Approximately 165 home economists from other states and from foreign countries I including the African and Latin American countries I participated in the conference.https://lib.dr.iastate.edu/card_reports/1026/thumbnail.jp

International home economics

The conference was planned to serve the interests of those who wish to work in home economics programs abroad and those who are concerned with the education of international students in the universities and colleges of the United States. Approximately 165 home economists from other states and from foreign countries I including the African and Latin American countries I participated in the conference.</p