Student Project Abstracts 2005 - Pluto - University of Washington

SNOEBERGERThe roll-over in the plots in chart 3 occur at approximatelytwice the vanderwaals radius of the chalcogen atom, whichis 3.7A for the sulfur analog, 4.0A for the selenium analog, and4.4A for the tellurium analog. The results of chart 3 show thatthe tellurium analog has a larger transfer integral at larger dimerdistances than that of the selenium and sulfur analogs, which isconsistent with the idea that a larger atomic radii will result ina larger transfer integral. However, this is not seen between thesulfur and selenium analogs which suggests that the interactionbetween the carbon orbitals dominant the electron splitting.The current work shows that including large chalcogen atomsin hole-transport materials results in desirably low reorganizationenergies and that the smaller molecules show an isomerdependence, which is more pronounced with the smaller chalcogenatoms. These systems are interesting for charge-transport andsynthesis is recommended.ACKNOWLEDGEMENTSResearch support is gratefully acknowledged from the NationalScience Foundation Center on Materials and Devices forInformation Technology Research (CMDITR), DMR-0120967.REFERENCES1. O.D. Jurchescu, J. Baas, T.T.M. Palstra, Appl. Phys. Lett. 84.3061-3063. (2004)2. J.H. Schon, Appl. Phys. Lett. 79. 4163-4162. (2001).3. M. Yamada, I. Ikemote, H. Kuroda, Bull. Chem. Soc Jpn.61.1057. (1988).4. O. Kwon, et. al. J. Chem. Phys. 120, 8186-8194. (2004).5. J.G. Laquindanum, H.E. Katz, A.J. Lovinger, J. Am. Chem.Soc. 120. 664-672. (1998).6. K.Takimiya, Y. Kunugi, Y, Konda, N. Niihara, T. Otsubo. J.Am. Chem. Soc. 126. 5084-5085. (2004).7. V. Coropceanu, J.M. Andre, M. Malagoli, J.L. Bredas. TheorChem Acc. 110. 59-69. (2003)8. M. Malagoli, V. Coropceanu, D.A. da Silva Filho, J.L. Bredas.J. Chem. Phys. 120, 7490-7496. (2004).9. M.J. Frisch, et al. Gaussian98, Revision A. 11, Gaussian, Incorporated:Wallingford, CT, 1998.10. P. Hohenberg and W. Kohn, Physical Review 136, B864-B871 (1964).11. R.G. Parr and W. Yang, Density-functional theory of atomsand molecules, Oxford Univ. Press: Oxford, (1989).12. A.D. Becke, J. Chem. Phys. 98 5648 (1993).13. T. H. Dunning, Jr. and P. J. Hay, in Modern Theoretical Chemistry,Ed. H. F. Schaefer, III, Plenum: New York, 1-28, (1976).14. P.J. Hay and W.R. Wadt, J. Chem. Phys. 82, 270 (1985).15. R. Ditchfield, W.J. Hehre and J.A. Pople, J. Chem. Phys. 54,724 (1971).16. AMPAC 8, © 1992-2004 Semichem, Inc. PO Box 1649,Shawnee, KS 66222.17. M.J.S. Dewar, E.G. Zoebisch, E.F. Healy, J.J.P. Stewart. J.Am. Chem. Soc. 107. 3902-3909. (1985).CMDITR Review of Undergraduate Research Vol. 2 No. 1 Summer 2005 105