Research in our lab uses a combination of microwave and ultraviolet spectroscopic techniques to study reaction dynamics of cold (~ 1K), isolated molecules in the gas phase.  We utilize a newly developed microwave technique called Chirped-Pulse Fourier Transform Microwave (CP-FTMW) to record ultra-broadband rotational spectra in seconds.  We use these techniques to study Excited State Dynamics and Combustion Processes.

Excited State Dynamics:  Our focus in this area is dedicated to studying long-term structural changes following electronic excitation after intramolecular processes have occurred. These final product states are “dark" to laser interrogation.  However our microwave techniques can probe these states as they only need a permanent dipole moment to couple with the incident microwave field.  The generality of the technique allows the study of a vast array of chemical species that cover many areas of current interest including biological molecules, combustion products, and exotic chemical species such as radicals and ions. 

Combustion Processes:  We use either a pulsed discharge nozzle or hyper-thermal source to generate propargyl radicals in a supersonic expansion.  The expansion anneals important intermediates on the reaction surface, which we then characterize with our microwave spectrometer, providing insight to important combustion pathways.  Future work will involve the study of oxygenated combustion products as well as atmospheric pollutants.

Education

Recognitions

• Dreyfus Foundation New Faculty Award, 2006

Selected Publications

• Dian BC, Clarkson JR, Zwier TS, Direct Measurement of Energy Thresholds to Conformational Isomerizaiton in Tryptamine. Science 2004 , 303, 1169-117.
• Dian BC, Florio GM, Clarkson JR, Longarte A, Zwier TS, Infrared Induced Conformational Isomerization and Vibrational Relaxation Dynamics in Melatonin and 5-Methoxy-n-acetyltryptophan Methylamide. J. Chem. Phys. 2004 , 120(19), 9033-9046.
• Evans DA, Dian BC, Zwier TS, Wales, DJ, The Dynamics of Conformational Isomerization in Flexible Biomolecules. II. Simulating isomerizations in a supersonic free jet with master equation dynamics. J. Chem. Phys. 2004 , 120(1), 148-157.
• Dian BC, Longarte A, Winter PR, Zwier TS, The Dynamics of Conformational Isomerization in Flexible Biomolecules. I. Hole-filling spectroscopy of N-acetyl tryptophan methyl amide and N-acetyl tryptophan amide. J. Chem. Phys. 2004 , 120(1), 133-147.