Josh Vura-Weis

Joint student of Profs. Mike Wasielewski and Mark Ratner

vura-weis@northwestern.edu

Synthetic, Spectroscopic, and Computational Investigation of Charge Transfer Through π Stacks

I am interested in charge transfer through π stacks because of its relevance to organic photovoltaic devices and thin-film transistors. In a self-assembled OPV or TFT, electrons and holes must hop from molecule to molecule, ideally through well-defined pi stacks:



In order to better understand the factors which determine the rate of charge transfer through such π stacks, I am in the process of synthesizing a series of donor-bridge-acceptor model complexes. This has been done extensively for linear molecules, but pi-stacked analogues are less common. Once the series is complete, I will use techniques such as femtosecond transient absorption (FSTA) to determine rates of charge transfer and EPR/ENDOR (in collaboration with other group members) to study charge sharing through the stack.

I also collaborate with the Lewis group to study hole transfer through DNA (refs 2-4 below). Lewis group members synthesize DNA strands with donor and acceptor molecules on each end, and I do FSTA to determine the rates of charge transfer through the stack.

Finally, I am part of the Small-Angle X-Ray Scattering (SAXS) team, which goes to the Advanced Photon Source at Argonne National Lab and uses their synchrotron radiation to determine the structure of self-assembled aggregates in solution.

Publications

  1. Structure-Property Relationship for Two-Photon Absorbing Multiporphyrins: Supramolecular Assembly of Highly-Conjugated Multiporphyrinic Ladders and Prisms
    Easwaramoorthi, S.; Jang, S. Y.; Yoon, Z. S.; Lim, J. M.; Lee, C.-W.; Mai, C.-L.; Liu, Y.-C.; Yeh, C.-Y.; Vura-Weis, J.; Wasielewski, M. R.; Kim, D.
    J. Phys. Chem. A; (Article); 2008; 112(29); 6563-6570. DOI: 10.1021/jp801626s

  2. Unexpectedly Similar Charge Transfer Rates Through Benzo-annulated Bicyclo[2.2.2]octanes
    Goldsmith, R. H.; Vura-Weis, J.; Vega, A.; Sen, A.; Borkar, S.; Ratner, M. A., Wasielewski, M. R.
    J. Am. Chem. Soc.; (Article); 2008; 130(24); 7659-7669. DOI:10.1021/ja8004623



  3. The Influence of Guanine on DNA Hole Transport Efficiency
    Lewis, F.D.; Daublain, P.; Cohen, B.; Vura-Weis, J.; Wasielewski, M. R.
    Angew. Chemie. Int. Ed.; (Communication) 2008; 47(20); 3798-3800. DOI:10.1002/anie.200705903



  4. Reversible Bridge-Mediated Excited-State Symmetry Breaking in Stilbene-Linked DNA Dumbbells
    Lewis, F. D.; Daublain, P.; Zhang, L.; Cohen, B.; Vura-Weis, J.; Wasielewski, M. R.; Shafirovich, V.; Wang, Q.; Raytchev, M.; Fiebig, T.
    J. Phys. Chem. B.; (Article); 2008; 112(12); 3838-3843. DOI: 10.1021/jp710718p



  5. Dynamics and Efficiency of DNA Hole Transport via Alternating AT versus Poly(A) Sequences
    Lewis, F. D.; Daublain, P.; Cohen, B.; Vura-Weis, J.; Shafirovich, V.; Wasielewski, M. R.
    J. Am. Chem. Soc.; (Communication); 2007; 129(49); 15130-15131. DOI: 10.1021/ja076876o



  6. Spectroscopic and DFT Investigation of [M{HB(3,5-iPr2pz)3}(SC6F5)] (M = Mn, Fe, Co, Ni, Cu, and Zn) Model Complexes: Periodic Trends in Metal-Thiolate Bonding
    Gorelsky, S. I.; Basumallick, L.; Vura-Weis, J.; Sarangi, R.; Hodgson, K. O.; Hedman, B.; Fujisawa, K.; Solomon, E. I.
    Inorg. Chem.; (Article); 2005; 44(14); 4947-4960. DOI: 10.1021/ic050371m
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