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2009-04-09 JMFrost - Fullerene Talk to Chemistry

2009-04-09 JMFrost - Fullerene Talk to Chemistry

An early version of the data on PCBM adducts (just Bis I think at this stage?). This was put together very quickly, for a talk over in Chemistry.

The results that followed from this were the key ones of my PhD.

To form the SMILES strings for PCBM with arbitrary attachment points, I borrowed a PhD friend's indoor Football (which is the same shape) and used post-it notes to locate the sidechains, while I rotated in in front of my eyes + checked that it agreed with the hand-annotated Schlegel diagrams in my lab book that I had built for each adduct.

I had evidently already started a combinatory sift, and found the CPDT fullerene, though hadn't yet managed to calculate Tris adducts.

Jarvist Moore Frost

April 09, 2009

More Decks by Jarvist Moore Frost

Other Decks in Science


  1. HOMO/LUMO of
    Fullerene Adducts
    A Quantum
    Chemical Study
    Jarvist Frost, James Kirkpatrick, Jenny Nelson
    Physics Department, Imperial College London

    View Slide

  2. Schlegel Diagram

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  3. SMILES (Simplified molecular input line entry specification)
    [C1 Isomer]
    [PBM Tail]
    (smi23d) (UFF,
    HOMO: Highest Occupied KS
    Energy Level (well defined)
    HOMO+1: First virt KS orbital
    (badly defined, but free)
    E(Anion)-E(Neutral): Further
    SCF calculation of charged
    molecule without nuclear
    coordinated relaxation
    HOMO+TD-DFT(1st Singlet):
    TD-DFT 'spectroscopic'

    View Slide

  4. View Slide

  5. View Slide

  6. View Slide

  7. Bis-Cyclopentadithiophene-PBM
    HOMO LUMO (eV)
    C1: -5.22893 -3.46713
    C2: -5.30618 -3.34498
    C3: -5.30590 -3.4574
    E': -5.28632 -3.34532
    T1: -5.27054 -3.44314
    T2: -5.29720 -3.4211
    T3: -5.37526 -3.47596
    T4: -5.32576 -3.43576
    Mono-PCBM: -3.74881
    Lifted HOMO (effect on working cell?)
    Lifted LUMO (~300meV c.f. Mono-pcbm)
    Homo spin density on Thiophene unit
    Thiophene unit fairly compact (effect on packing)
    Further Work: Different adducts, higher order adducts
    Understanding effect of varying Lumo of isomers on performance (fill factor?)
    Combine with simplistic MD to generate amorphous films + charge transport studies

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  8. Comparison of DFT Methods for Molecular Orbital Eigenvalue Calculations –
    Gang Zhang et al. J. Phys. Chem. A 2007, 111, 1554-1561
    Principles of Fullerene Reactivity – Andreas Hirsch. Topics in Current Chemistry, Vol.
    Fullerene Chemistry in Three Dimensions – Andreas Hirsch et al. Angew. Chem. Int.
    Ed. Engl. 1994, 33, No. 4
    The Addition Patterns of C60 Trisadducts – Francis Djojo et al. Eur. J. Org. Chem.
    1999, 3027-3039
    Lecture Notes on Fullerene Chemistry – Roger Taylor, Imperial College Press 1999
    Pi-Conjugated Fullerene Adducts – Floris Berend Kooistra, PhD Thesis 2007,
    University of Groningen
    Acknowledgments and References
    Jenny Nelson (Supervisor)
    James Kirkpatrick (Gaussian Assistance + awk scripts)
    Kevin Gilbert, Rajarshi Guha - Indiana University (smi23d coordinate generation)
    Other Software: Openbabel, Gaussian 03, PyMol
    High Performance Computing facility, Imperial College London (2.5 CPU-Years)

    View Slide