Vibrational energy transfer after exciting the a.) nitro or b.) ring

1. Nitrobenzene, a vibrational diodeDana D. Dlott, University of Illinois at Urbana-Champaign, DMR 0855259 Fourier’s law effectively describes heat transfer on macroscopic scales such as heat traveling from a hot to a cold end of a metal wire. On the molecular scale, quantum effects steer this transfer in a way that is less intuitive. To study this process, graduate student Brandt Pein excited liquids of substituted benzenes with a tunable near-IR pulse while the vibrational energy was transiently probed with a visible pulse. These types of molecules offer a wide range of structures who’s transfer dynamics can be readily compared. Nitrobenzene demonstrates a fascinating diode-like behavior when nitro or ring vibrations are initially excited. This is entirely unique compared to all other substituted benzenes we’ve studied. Understanding these processes is relevant to molecular scale electronics and machines were dissipation of energy may prove detrimental to their performance and functionality. Vibrational energy transfer after exciting the a.) nitro or b.) ring Evib(nitro) Evib (ring) a. b. pulse Evib (Jcm-3) Δt(picoseconds) Δt Δt only nitro ring + nitro After excitation with a near-IR laser pulse tuned to a nitro- or ring-localized vibration, energy is transported in a diode-like fashion where b.) ring-to-nitro transfer is facile while a.) nitro-to-ring is not.

2. Bonding with chemistry: a girls’ day campDana D. Dlott, University of Illinois at Urbana-Champaign, DMR 0855259 Dlott’s student Kathryn Brown was the coordinator of 2011 “Bonding with chemistry: a girls’ day camp” . This event is sponsored by ACS and the U of I chemistry department. His students Yuanxi Fu, Elizabeth Friedman and Chris Berg are volunteers that helped organize this event. The day camp is designed to encourage girls entering grades 5-8 to discover chemistry through hands-on experiments and demonstrations. The day camp opens with an exciting kick-off demonstration. Each year we provide four experimental stations with different themes. Volunteers design or adapt experiments that get participants actively involved in chemistry that they find tangible connections with their everyday lives. For example, this year’s camp involves forensic chemistry, chemistry in art and colors, natural products and “Tie-Dye” T-shirt Chromatography. The day camp ends with the ever-popular liquid nitrogen ice cream party.