General Lab Information

Electron- and Photo-Induced Processes banner image

Electron- and Photo-Induced Processes

Publications Concerning LEAF and Work Done at LEAF

  1. The Brookhaven Laser-Electron Accelerator Facility (LEAF)
    J. F. Wishart
    Houshasenkagaku (Biannual Journal of the Japanese Society of Radiation Chemistry) 66, 63-64 (1998)
  2. Electron Attachment to CO2 in Supercritical Ethane
    M. Nishikawa, K. Itoh, and R. Holroyd
    J. Phys. Chem. A 103, 550-556 (1999) Abstract [Find paper at ACS Publications]
  3. Thermodynamics of Electron Attachment to Pyrimidine and Styrene in Supercritical Ethane
    R. A. Holroyd, M. Nishikawa, and K. Itoh
    J. Phys. Chem. B 103, 9205-9210 (1999) Abstract [Find paper at ACS Publications]
  4. Solvent Clustering around Pyrazine Ions in the High-Compressibility Region of Supercritical Ethane
    R. A. Holroyd, M. Nishikawa, and K. Itoh
    J. Phys. Chem. B 104, 11585-11590 (2000) Abstract [Find paper at ACS Publications]
  5. Rapid electron tunneling through oligophenylenevinylene bridges.
    H. D. Sikes, J. F. Smalley, S. P. Dudek, A. R. Cook, M. D. Newton, C. E. D. Chidsey, and S. W. Feldberg
    Science 291, 1519-1523 (2001) Abstract [Find paper at Science Magazine]
  6. Accelerators for Ultrafast Phenomena
    J. F. Wishart
    In "Radiation Chemistry: Present Status and Future Trends" C. D. Jonah, B. S. M. Rao, Eds.; Studies in Physical and Theoretical Chemistry, Vol. 87, Ch. 2, Elsevier Science, (2001), pp. 21-35. (ISBN 0-444-82902-4) [Information about the book]
  7. Pulse Radiolysis Studies of Dendritic Macromolecules with Biphenyl Peripheral Groups and a Ruthenium Tris-bipyridine Core
    T. H. Ghaddar, J. F. Wishart, J. P. Kirby, J. K. Whitesell, and M. A. Fox
    J. Am. Chem. Soc. 123, 12832-12836 (2001) Abstract [Find paper at ACS Publications]
  8. A Dendrimer-Based Electron Antenna: Paired Electron Transfer Reactions in Dendrimers with a 4,4'-bipyridine Core and Naphthalene Peripheral Groups
    T. H. Ghaddar, J. F. Wishart, D. W. Thompson, J. K. Whitesell, and M. A. Fox
    J. Am. Chem. Soc. 124, 8285-8289 (2002) Abstract [Find paper at ACS Publications]
  9. Density Inhomogeneities and Electron Mobility in Supercritical Xenon
    R. A. Holroyd, K. Itoh, and M. Nishikawa
    J. Chem. Phys. 118, 706-710 (2003) Abstract [Find paper at Scitation]
  10. Spectrum and Reactivity of the Solvated Electron in the Ionic Liquid Methyltributylammonium Bis(trifluoromethylsulfonyl)imide
    J. F. Wishart and P. Neta
    J. Phys. Chem. B 107, 7261-7267 (2003). Abstract [Find paper at ACS Publications] or use ACS Articles on Request
  11. Reactions of Charged Species in Supercritical Xenon as Studied by Pulse Radiolysis
    R. A. Holroyd, J. F. Wishart, M. Nishikawa, and K. Itoh
    J. Phys. Chem. B 107, 7281-7287 (2003). Abstract [Find paper at ACS Publications]
  12. Radiation Chemistry of Ionic Liquids: Reactivity of Primary Species
    J. F. Wishart, in "Ionic Liquids as Green Solvents: Progress and Prospects" Rogers, R. D. and Seddon, K. R., Eds.; ACS Symp. Ser. 856, Ch. 31, American Chemical Society, Washington, DC, 2003, pp. 381-396. (ISBN 0-84123-856-1) Abstract [Information about the book]
  13. Pulse Radiolysis Study of the Reactions of Hydrogen Atoms in the Ionic Liquid Methyltributylammonium Bis(trifluoromethylsulfonyl)imide
    J. Grodkowski, P. Neta and J. F. Wishart
    J. Phys. Chem. A 107, 9794-9799 (2003). Abstract [Find paper at ACS Publications] or use ACS Articles on Request
  14. Charge Transfer through Terthiophene End-Capped Poly(arylene ethynylene)s
    A. M. Funston, E. E. Silverman, J. R. Miller, and K. S. Schanze
    J. Phys. Chem. B 108, 1544-1555 (2004). Abstract [Find paper at ACS Publications]
  15. Faster Dissociation: Measured Rates and Computed Effects on Barriers in Aryl Halide Radical Anions
    N. Takeda, P. V. Poliakov, A. R. Cook, and J. R. Miller
    J. Am. Chem. Soc. 126, 4301-4309 (2004). Abstract [Find paper at ACS Publications]
  16. Long-Range Electron Transfer across Peptide Bridges: the Transition from Electron Superexchange to Hopping
    R. Abdel Malak, Z. Gao, J. F. Wishart, and S. S. Isied
    J. Am. Chem. Soc. 126, 13888-13889 (2004). Abstract [Find paper at ACS Publications]
  17. The LEAF Picosecond Pulse Radiolysis Facility at Brookhaven National Laboratory
    J. F. Wishart, A. R. Cook and J. R. Miller
    Rev. Sci. Inst. 75, 4359-4366 (2004). Abstract and Download [Find paper at Scitation]
    Also selected for the December 2004 issue of the Virtual Journal of Ultrafast Science.
  18. Electron Attachment to C60 in Nonpolar Solvents
    R. A. Holroyd
    Radiat. Phys. Chem., 72, 79-84 (2005). Abstract [Find paper at Elsevier Science Direct]
  19. Effects of Functional Group Substitution on Electron Spectra and Solvation Dynamics in a Family of Ionic Liquids
    J. F. Wishart, S. I. Lall-Ramnarine, R. Raju, A. Scumpia, S. Bellevue, R. Ragbir, R. Engel
    Radiat. Phys. Chem., 72, 99-104 (2005). Abstract [Find paper at Elsevier Science Direct]
  20. Increased Yields of Radical Cations by Arene Addition to Irradiated 1,2-Dichloroethane
    A. M. Funston and J. R. Miller
    Radiat. Phys. Chem., 72, 601-611 (2005). Abstract [Find paper at Elsevier Science Direct]
  21. Convergence of Spectroscopic and Kinetic Electron Transfer Parameters for Mixed-Valence Binuclear Dipyridylamide Ruthenium Ammine Complexes
    A. J. Distefano, J. F. Wishart, and S. S. Isied
    Coord. Chem. Rev. 249, 507-516 (2005). Abstract [Find paper at Elsevier Science Direct]
  22. Dynamics of Fast Reactions in Ionic Liquids
    A. M. Funston and J. F. Wishart, in "Ionic Liquids IIIA: Properties and Structure" Rogers, R. D. and Seddon, K. R., Eds.; ACS Symp. Ser. 901, Ch. 8, American Chemical Society, Washington, DC, 2005, pp. 102-116. (ISBN 0-8412-3893-6) Abstract [Information about the book]
  23. Radiolysis with RF Photoinjectors: Supercritical Xenon Chemistry
    J. F. Wishart, in "Femtosecond Beam Science" Uesaka, M., Ed.; Imperial College Press, London, 2005, pp. 351-356. (ISBN 1-86094-343-8) Abstract [Information about the book]
  24. Rates and energy of reactions of charged species in supercritical xenon
    R. A. Holroyd, M. Nishikawa and K. Itoh
    Radiat. Phys. Chem., 74, 146-151 (2005). Abstract [Find paper at Elsevier Science Direct]
  25. One-Electron Reduction of an "Extended Viologen" p-Phenylene-bis-4,4'-(1-aryl-2,6-diphenylpyridinium) Dication
    A. Funston, J. P. Kirby, J. R. Miller, L. Pospíšil, J. Fiedler, M. Hromadová, M. Gál, J. Pecka, M. Valášek, Z. Zawada, P. Rempala, and J. Michl
    J. Phys. Chem. B 109, 10862-10869 (2005). Abstract [Find paper at ACS Publications]
  26. Reactivity of Acid Generators for Chemically Amplified Resists with Low-Energy Electrons
    A. Nakano, T. Kozawa, S. Tagawa, T. Szreder, J. F. Wishart, T. Kai and T. Shimokawa
    Jpn. J. Appl. Phys. 45, L197-L200 (2006). Abstract [Find paper at the Japanese Journal of Applied Physics]
  27. Spectroscopy and Transport of the Triplet Exciton in a Terthiophene End-Capped Poly(phenylene ethynylene)
    A. M. Funston, E. E. Silverman, K. S. Schanze, and J. R. Miller
    J. Phys. Chem. B 110, 17736-17742 (2006). Abstract [Find paper at ACS Publications]
  28. Nature and Energies of Electrons and Holes in a Conjugated Polymer, Polyfluorene
    N. Takeda, S. Asaoka, and J. R. Miller
    J. Am. Chem. Soc. 128, 16073-16082 (2006). Abstract [Find paper at ACS Publications]
  29. Conformational Analysis of the Electron-Transfer Kinetics across Oligoproline Peptides Using N,N-Dimethyl-1,4-benzenediamine Donors and Pyrene-1-sulfonyl Acceptors
    J. B. Issa, A. S. Salameh, E. W. Castner, Jr., J. F. Wishart, and S. S. Isied
    J. Phys. Chem. B 111, 6878-6886 (2007). Abstract [Find paper at ACS Publications] or use ACS Articles on Request
  30. Rate and Driving Force for Protonation of Aryl Radical Anions in Ethanol
    A. M. Funston, S. V. Lymar, B. Saunders-Price, G. Czapski, and J. R. Miller
    J. Phys. Chem. B 111, 6895-6902 (2007). Abstract [Find paper at ACS Publications]
  31. Mobility of electrons in supercritical krypton: Role of density fluctuations
    M. Nishikawa, R. A. Holroyd and J. M. Preses
    J. Chem. Phys. 127, 014504 (2007). Abstract [Find paper at Scitation]
  32. Radical Ion States of Platinum Acetylide Oligomers
    Thomas Cardolaccia, Alison M. Funston, M. Erkan Kose, Julia M. Keller, John R. Miller, and Kirk S. Schanze
    J. Phys. Chem. B 111, 10871-10880 (2007). Abstract [Find paper at ACS Publications]
  33. Trialkylammonio-Dodecaborates: Anions for Ionic Liquids with Potassium, Lithium and Proton as Cations
    E. Justus, K. Rischka, J. F. Wishart, K. Werner and D. Gabel
    Chem. Eur. J. 14, 1918-1923 (2008). Abstract [Find paper at Wiley InterScience]
  34. Tools for radiolysis studies
    J. F. Wishart, in "Radiation chemistry: from basics to applications in material and life sciences" Spotheim-Maurizot, M., Douki, T., Mostafavi, M., and Belloni, J., Eds.; L'Actualité Chimique Livres, Paris, (2008) Ch. 2, pp. 17-33. [Information about the book]
  35. Electron and hole transport to trap groups at the ends of conjugated polyfluorenes
    S. Asaoka, N. Takeda, T. Lyoda, A. R. Cook and J. R. Miller
    J. Am. Chem. Soc. 130, 11912-11920 (2008). Abstract [Find paper at ACS Publications]
  36. Length and Time-Dependent Rates in Diffusion-Controlled Reactions with Conjugated Polymers
    P. Sreearunothai, S. Asaoka, A. R. Cook and J. R. Miller
    J. Phys. Chem. A 113, 2786-2795 (2009). Abstract [Find paper at ACS Publications]
  37. Charge trapping in imidazolium ionic liquids
    I. A. Shkrob and J. F. Wishart
    J. Phys. Chem. B 113, 5582-5592 (2009). Abstract [Find paper at ACS Publications] or use ACS Articles on Request
  38. Optical fiber-based single-shot picosecond transient absorption spectroscopy
    A. R. Cook and Yuzhen Shen
    Rev. Sci. Inst. 80, 073106 (2009). Abstract and Download [Find paper at Scitation]
  39. Synthesis, characterization and radiolytic properties of bis(oxalato)borate containing ionic liquids
    S. I. Lall-Ramnarine, A. Castano, G. Subramaniam, M. F. Thomas and J. F. Wishart
    Radiat. Phys. Chem., 78, 1120-1125 (2009). Abstract [Find paper at Elsevier Science Direct]
  40. Dynamics of Excimer Formation and Decay in Supercritical Krypton
    R. A. Holroyd, A. R. Cook and J. M. Preses
    J. Chem. Phys. 131, 224509 (2009). Abstract [Find paper at Scitation]
  41. Toward Designed Singlet Fission: Electronic States and Photophysics of 1,3-Diphenylisobenzofuran
    A. F. Schwerin, J. C. Johnson, M. B. Smith, P. Sreearunothai, D. Popovic, J. Cerny, Z. Havlas, I. Paci, A. Akdag, M. K. MacLeod, X. Chen, D. E. David, M. A. Ratner, J. R. Miller, A. J. Nozik and J. Michl
    J. Phys. Chem. A 114, 1457-1473 (2010). Abstract [Find paper at ACS Publications]
  42. Ultra-fast pulse radiolysis methods
    J. Belloni, R. A. Crowell, Y. Katsumura, M. Lin, J.-L. Marignier, M. Mostafavi, Y. Muroya, A. Saeki, S. Tagawa, Y. Yoshida, V. De Waele, and J. F. Wishart, in "Recent Trends in Radiation Chemistry" Rao, B. S. M. and Wishart, J. F., Eds.; World Scientific, Singapore, (2010) Ch. 5, pp 121-160. [Information about the book]
  43. Application of External-Cavity Quantum Cascade Infrared Lasers to Nanosecond Time-Resolved Infrared Spectroscopy of Condensed-Phase Samples Following Pulse Radiolysis
    D. C. Grills, A. R. Cook, E. Fujita, M. W. George, J. M. Preses, and J. F. Wishart
    Appl. Spectrosc. 64, 563-570 (2010). Abstract [Find paper at Ingenta]
  44. Conjugated "Molecular Wire" for Excitons
    Y. Shibano, H. Imahori, P. Sreearunothai, A. R. Cook and J. R. Miller
    J. Phys. Chem. Lett. 1, 1492-1496 (2010). Abstract [Find paper at ACS Publications]
  45. Ionic Liquids and Ionizing Radiation: Reactivity of Highly Energetic Species
    J. F. Wishart
    J. Phys. Chem. Lett. 1, 3225-3231 (2010). Abstract [Find paper at ACS Publications] or use ACS Articles on Request
  46. Negative Polaron and Triplet Exciton Diffusion in Organometallic "Molecular Wires"
    J. M. Keller, K. D. Glusac, E. O. Danilov, S. McIlroy, P. Sreearunothai, A. R. Cook, H. Jiang, J. R. Miller and K. S. Schanze
    J. Am. Chem. Soc. 133, 11289-11298 (2011). Abstract [Find paper at ACS Publications]
  47. Triplet Transport to and Trapping by Acceptor End Groups on Conjugated Polyfluorene Chains
    P. Sreearunothai, A. Estrada, S. Asaoka, M. Kowalczyk, S. Jang, A. R. Cook, J. M. Preses and J. R. Miller
    J. Phys. Chem. C 115, 19569-19577 (2011). Abstract [Find paper at ACS Publications]
  48. Sudden, "Step" Electron Capture by Conjugated Polymers
    A. R. Cook, P. Sreearunothai, S. Asaoka and J. R. Miller
    J. Phys. Chem. A 115, 11615-11623 (2011). Abstract [Find paper at ACS Publications]
  49. Electron solvation dynamics and reactivity in ionic liquids observed by picosecond radiolysis techniques
    J. F. Wishart, A. M. Funston, T. Szreder, A. R. Cook and M. Gohdo
    Faraday Discuss. 154, 353-363 (2012). Abstract [Find paper at RSC Publications].
  50. Radiation Induced Fragmentation of Diamide Extraction Agents in Ionic Liquid Diluents
    I. A. Shkrob, T. W. Marin, J. R. Bell, H. Luo, S. Dai, J. L. Hatcher, R. D. Rimmer, and J. F. Wishart
    J. Phys. Chem. B 116, 2234-2243 (2012). Abstract [Find paper at ACS Publications] or use ACS Articles on Request.
  51. Polarons, Bipolarons, and Side-By-Side Polarons in Reduction of Oligofluorenes
    L. Zaikowski, P. Kaur, C. Gelfond, E. Selvaggio, S. Asaoka, Q. Wu, H.-C. Chen, N. Takeda, A. R. Cook, A. Yang, J. Rosanelli and J. R. Miller
    J. Am. Chem. Soc. 134, 10852-10863 (2012). Abstract [Find paper at ACS Publications]
  52. Nanosecond Pulse Radiolysis of Nanoconfined Water
    R. M. Musat, A. R. Cook, J.-P. Renault and R. A. Crowell
    J. Phys. Chem. C 116, 13104-13110 (2012). Abstract [Find paper at ACS Publications].
  53. Poly(3-decylthiophene) Radical Anions and Cations in Solution: Single and Multiple Polarons and Their Delocalization Lengths in Conjugated Polymers
    N. Takeda and J. R. Miller
    J. Phys. Chem. B 116, 14715-14723 (2012). Abstract [Find paper at ACS Publications].
  54. Excitons and Excess Electrons in Nanometer Size Molecular Polyoxotitanate Clusters: Electronic Spectra, Exciton Dynamics, and Surface States
    Jianhua Bao, Zhihao Yu, Lars Gundlach, Jason B. Benedict, Philip Coppens, Hung Cheng Chen, John R. Miller and Piotr Piotrowiak
    J. Phys. Chem. B 117, 4422-4430 (2013). Abstract [Find paper at ACS Publications].
  55. Rapid "Step Capture" of Holes in Chloroform during Pulse Radiolysis
    Andrew R. Cook, Matthew J. Bird, Sadayuki Asaoka and J. R. Miller
    J. Phys. Chem. A 117, 7712-7720 (2013). Abstract [Find paper at ACS Publications]
  56. Radiation Stability of Cations in Ionic Liquids. 2. Improved Radiation Resistance Through Charge Delocalization in 1-Benzylpyridinium
    I. A. Shkrob, T. W. Marin, Jasmine L. Hatcher, Andrew R. Cook, Tomasz Szreder and J. F. Wishart
    J. Phys. Chem. B 117, 14385-14399 (2013). Abstract [Find paper at ACS Publications] or use ACS Articles on Request.
  57. Electron Transfer by Excited Benzoquinone Anions: Slow Rates for Two-Electron Transitions
    M. Zamidar, A. R. Cook, A. Lewandowska-Andralojc, R. Holroyd, Y. Jiang, J. Bikalis and J. R. Miller
    J. Phys. Chem. A 117, 8360-8367 (2013). Abstract [Find paper at ACS Publications].
  58. Polarons, Compressed Polarons, and Bipolarons in Conjugated Polymers
    J. Bakalis, A. R. Cook, S. Asaoka, M. Forster, U. Scherf and J. R. Miller
    J. Phys. Chem. C 118, 114-125 (2014). Abstract [Find paper at ACS Publications].
  59. Pressure Tuning of Electron Attachment to Benzoquinones in Nonpolar Fluids: Continuous Adjustment of Free Energy Changes
    R. Holroyd, J. R. Miller, A. R. Cook and M. Nishikawa
    J. Phys. Chem. B 118, 2164-2171 (2014). Abstract [Find paper at ACS Publications].
  60. Ionic Liquid Radiation Chemistry
    J. F. Wishart in "Ionic Liquids further UnCOILed: Critical Expert Overviews," N. Plechkova; K. R. Seddon, Eds. Wiley, Ltd.: Chichester, (2014) pp. 259-274. Abstract
  61. Mechanism of the Formation of a Mn-Based CO2 Reduction Catalyst Revealed by Pulse Radiolysis with Time-Resolved Infrared Detection
    D. C. Grills, J. A. Farrington, B. H. Layne, S. V. Lymar, B. A. Mello, J. M. Preses and J. F. Wishart
    J. Am. Chem. Soc. 136, 5563-5566 (2014). Abstract [Find paper at ACS Publications].
  62. Tetraarylcyclobutadienecyclopentadienylcobalt Complexes: Synthesis, Electronic Spectra, Magnetic Circular Dichroism, Linear Dichroism, and TD DFT Calculations
    G. S. Kottas, T. Brotin, P. F. H. Schwab, K. Gala, Z. Havlas, J. P. Kirby, J. R. Miller, and J. Michl
    Organometallics 33, 3251-3264 (2014). Abstract [Find paper at ACS Publications].
  63. Radiation Stability of Cations in Ionic Liquids. 5. Task-Specific Ionic Liquids Consisting of Biocompatible Cations and the Puzzle of Radiation Hypersensitivity
    I. A. Shkrob, T. W. Marin, J. F. Wishart, and D. C. Grills
    J. Phys. Chem. B 118, 10477-10492 (2014). Abstract [Find paper at ACS Publications].
  64. Role of Bad Dihedral Angles: Methylfluorenes Act as Energy Barriers for Excitons and Polarons of Oligofluorenes
    T. Mani and J. R. Miller
    J. Phys. Chem. A 118, 9451-9459 (2014). Abstract [Find paper at ACS Publications]
  65. Transport of Triplet Excitons along Continuous 100 nm Polyfluorene Chains
    X. Li, M. Bird, G. Mauro, S. Asaoka, A. R. Cook, H.-C. Chen and J. R. Miller
    J. Phys. Chem. B 119, ASAP (2015). Abstract [Find paper at ACS Publications]
  66. Vibrational Stark Effects to Identify Ion Pairing and Determine Reduction Potentials in Electrolyte-Free Environments
    T. Mani, D. C. Grills and J. R. Miller
    J. Am. Chem. Soc. 137, ASAP (2015). Abstract [Find paper at ACS Publications]
  67. A comparison of the gamma-radiolysis of TODGA and T(EH)DGA using UHPLC-ESI-MS analysis
    C. A. Zarzana, G. S. Groenewold, B. J. Mincher, S. P. Mezyk, A. Wilden, H. Schmidt, G. Modolo, J. F. Wishart and A. R. Cook
    Solvent Extr. Ion Exch. 33, 431-447 (2015). [Find paper at Taylor and Francis]
  68. Development of nanosecond time-resolved infrared detection at the LEAF pulse radiolysis facility
    D. C. Grills, J. A. Farrington, B. H. Layne, J. M. Preses, H. J. Bernstein and J. F. Wishart
    Rev. Sci. Instrum. 86, 044102 (2015). [Find paper at AIP]
  69. A design strategy for intramolecular singlet fission mediated by charge-transfer states in donor-acceptor organic materials
    E. Busby, J. L. Xia, Q. Wu, J. Z. Low, R. Song, J. R. Miller, X. Y. Zhu, L. M. Campos, M. Y. Sfeir
    Nature Materials 14, 426-433 (2015). [Find paper at Nature Publications].
  70. What Makes Fluoroethylene Carbonate Different?
    I. A. Shkrob, J. F. Wishart, and D. P. Abraham
    J. Phys. Chem. C 119, 14954-14964 (2015). [Find paper at ACS Publications] or use ACS Articles on Request.
  71. Singlet, triplet, electron and hole transport along single polymer chains
    M. Bird, G. Mauro, L. Zaikowski, X. Li, O. Reid, B. Karten, S. Asaoka, H.-C. Chen, A. R. Cook, G. Rumbles and J. R. Miller
    Proc. SPIE 9549, Physical Chemistry of Interfaces and Nanomaterials XIV 95490E (2015). [Find paper at SPIE].
  72. Electron Localization of Anions Probed by Nitrile Vibrations
    T. Mani, D. C. Grills, M. D. Newton and J. R. Miller
    J. Am. Chem. Soc. 137, 10979-10991 (2015). [Find paper at ACS Publications].
  73. Identification of Ion-Pair Structures in Solution by Vibrational Stark Effects
    J. Hack, D. C. Grills, J. R. Miller and T. Mani
    J. Phys. Chem. B 120, 1149-1157 (2016). [Find paper at ACS Publications].
  74. The role of organic solvent radical cations in separations ligand degradation
    S. P. Mezyk, B. J. Mincher, S. B. Dhiman, B. Layne and J. F. Wishart
    J. Radioanal. Nucl. Chem. 307, 2445-2449 (2016). [Find paper at Springer].

About the EPIP Group

We apply both photoexcitation and ionization by short pulses of fast electrons to investigate fundamental chemical problems relevant to the production and efficient use of energy.

About LEAF

Research Highlights

Ionic Liquids: Designer Solvents for a Cleaner World (PDF)

Storing Energy in Dendrimer Trees: Stabilizing Charge Separation in Dendrimers (PDF)

They Bend Before They Break: Fast Scission of Chemical Bonds (PDF)