The Origination of Soot Formation A Study on

The Origination of Soot Formation: A Study on Ethyl-Linked Naphthalene Dimers Daniel M. Hewett, Victoria Boulos, and Timothy S. Zwier Department of Chemistry, Purdue University Funding: DOE Basic Energy Sciences Combustion Program Funding 1

Motivations ? + 2

Isomers 2, 2 1, 1 1, 2 Dr. Anthony Tomaine 3

Conformations Stacked (90, g, 90) Extended (90, t, 90) Partially Stacked (90, g, 90) Planar (180, t, 180) 4

Calculated Energies b 3 lyp/Def 2 TZVP with Grimme dispersion correction 5

Fluorescence Excitation and Dispersed Fluorescence Chamber t total Detec cence s fluore UV laser tuned A*(S 1) Conformer A (S 0, ZPL) 6

Laser Schemes Tune UV Laser Collect Total Fluorescence Fix UV Laser Collect Total Fluorescence Tune IR Laser LIF S 0 -FDIRS 7

Laser Schemes Fix First UV Laser Collect Total Fluorescence Tune Second UV Laser UVUV Holeburning 8

1, 1 UV Excitation Spectra Colored Spectra = Conformer-Specific Black Spectrum = Non Conformer-Specific LIF 9

1, 1 UV Excitation Spectra LIF R 2 PI 10

1, 1 UV Excitation Spectra 1, 1 1 -Ethylnaphthalene 11

2, 2 UV Excitation Spectra 2, 2 2 -Ethylnaphthalene 12

1, 2 UV Excitation Spectra 13

1, 1 IR Spectra 14

1, 1 IR Spectra Conformer 1 0 k. J/mol Stacked Conformer 2 1. 8 k. J/mol Partially Stacked Conformer 3 4. 5 k. J/mol Partially Stacked 15

2, 2 IR Spectra 16

2, 2 IR Spectra Conformer 1 0 k. J/mol Stacked Conformer 2 1. 6 k. J/mol Partially Stacked Conformer 3 3. 4 k. J/mol Partially Stacked 17

1, 2 IR Spectra 18

1, 2 IR Spectra Conformer 1 0 k. J/mol Stacked Conformer 2 1. 4 k. J/mol Partially Stacked Conformer 3 2. 3 k. J/mol Partially Stacked Conformer 4 7. 3 k. J/mol Extended 19

Future Work • Analysis of dispersed fluorescence spectra • Further collaboration with theory groups • Ethyl-linked anthracene dimers 20

Acknowledgements • • • Dr. Tim Zwier Dr. Anthony Tomaine Victoria Boulos The Zwier group DOE 21