Some monosubstituted benzenes have unidirectional vibrational energy flowDana D. Dlott, University of Illinois, DMR 0855025 • toluene • CH3- pumping • (b) phenyl pumping In our efforts to understand how vibrational energy flows within molecules, we studied a variety of monosubstituted benzenes R-f (R = NH2, NO2, CH3) in the liquid state. We depos-ited energy in states localized on the substitutent or on the phenyl group. While energy flowed efficiently from phenyl to substituent, the reverse did not occur. We used a 3D vibrational spectroscopy technique to determine which IR wavelengths produced highly localized excitations on the molecules and to probe all the vibrational energy in the molecule. We divided up the vibrations into three groups, phenyl, local substitutent and global and used quantum chemical calculations to show that substituent energy did not couple well to phenyl and global modes. These studies help us understand how to design molecules that promote unidirectional energy transfer (i.e. thermal diodes).
Bonding with chemistry: a girls’ day campDana D. Dlott, University of Illinois, DMR 0855025 Dlott’s student Kathryn Brown was the coordinator of “Bonding with chemistry: a girls’ day camp” in 2011 and 2012. This event is sponsored by ACS and the U of I chemistry department. Dlott’s students Yuanxi Fu, Bruno Guiliani Nicolau and Chris Berg were 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 experiment 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 involve forensic chemistry, chemistry in art and colors, natural products and “Tie-Dye” T-shirt Chromatography. The day camp ends with ever-popular liquid nitrogen ice cream party.