|
|
Edwin F. Hilinski
|
Go to
|
Applications are now being accepted for our Summer National Science Foundation - Research Experiences for Undergraduates (NSF-REU) Program: Sunshine Institute for the
Interaction of Light with Matter
|
Department of
Chemistry and Biochemistry |
|
TEL:
850-644-5503 |
Research Interests: Mechanistic
studies of photochemical and thermal reactions of organic compounds in
solution; picosecond laser spectroscopy; photoinduced
phenomena in the solid state.
Many important phenomena that interact to determine the
outcome of a chemical reaction occur in the time regime from 10-12
to 10-6 seconds. These dynamic processes include electron and energy
transfer, bond dissociation and formation, unimolecular rearrangement,
diffusion, and interactions between reactants and between reactant and solvent.
Our research primarily focuses on studies of reacting organic molecules and
interactions that they have with their environment. A method on which we rely
is picosecond laser spectroscopy. Intermediates whose lifetimes are as short as
10 ps can be generated and detected via
absorption or emission spectroscopy. We synthesize compounds designed to reveal
mechanistic intricacies when probed spectroscopically.
Several researches are highlighted here:
(1) Photodissociations of sigma bonds in organic molecules in solution often give fragments formally resulting from bond homolysis and bond heterolysis. We are investigating the paths of deactivation from an initially populated pi,pi* excited state leading to the production of radicals and ions. A variety of possibilities are outlined in Scheme I. The fragments that are formed also permit studies of their ground-state reactivities.
(2) The twisted excited singlet state (1p*) of a polyarylalkene may be considered to be composed of contributions from zwitterionic (I), singly (II), and doubly (III) excited states. Our time-resolved spectroscopic studies have provided evidence for the assignment of the zwitterionic form (I) as the dominant electronic contributor to the lowest 1p* of several substituted tetraphenylethenes. Substituted polyarylethenes are under investigation to evaluate the contributions of I, II, and III to 1p*.
(3) The excited-state reactivity of transient species in the subnanosecond time domain via time-resolved spectroscopy is an area that we are investigating with the three-pulse laser system that we developed.
(4) Photoinduced electron transfer, involving excitation of ground-state organic electron donor-acceptor complexes, is being studied to learn the roles of orbital symmetries and the effects of heavy atoms on electron-transfer rates in solution.
(5) Photophysical phenomena associated with semiconducting and superconducting materials are under investigation through several collaborations.
In our research, we strive to learn how electrons are apportioned in these processes and how our results compare with theoretical predictions.
SELECTED PUBLICATIONS
Manny, T. F.; Shonde, T. B.; Liu, H.; Islam, M. S.; Olasupo, O. J.; Viera, J.; Moslemi, S.; Khizr, M.; Chung, C.; Winfred, J. S. R. V.; Stand, L. M.; Hilinski, E. F.; Schlenoff, J.; Ma, B. "Efficient X-Ray Scintillators Based on Facile Solution Processed 0D Organic Manganese Bromide Hybrid Films," Advanced Functional Materials 2024, 2413755 (1-7). https://doi.org/10.1002/adfm.202413755
Saltiel, J.; Krishnan, S.B.; Gupta, S.; Chakraborty, A.; Hilinski, E.F.; Lin, X. "Photochemistry and Photophysics of Cholesta-5,7,9(11)-trien-3β-ol in Ethanol," Molecules 2023, 28, 4086. https://doi.org/10.3390/molecules28104086
Krishnan, S. B.; Clark, R. J.; Lin, X.; Dmitrenko, O.; Hilinski, E. F.; Kuhn, L. R.; Alabugin, I. V.; Saltiel, J., "α-Methylstilbene
Isomers: Relationship of Structure to Photophysics and Photochemistry," J.
Phys. Chem. A 2022, 126, 8975-8987. https://doi.org/10.1021/acs.jpca.2c06319
Hilinski, E. F, "The
Picosecond Realm," in Reactive
Intermediate Chemistry, Moss, R. A.; Platz,
M. S.; Jones, M., Jr., Eds., Wiley-Interscience, New
York, 2004, p. 873. https://doi.org/10.1002/0471721492.ch19
Takahashi, Y.; Ohaku, H.; Nishioka, N.; Ikeda,
H.; Miyashi, T.; Gormin, D.
A.; Hilinski, E. F., "Charge-Transfer Excitation of Electron
Donor-Acceptor Complexes of Arylcyclopropanes," J.
Chem. Soc., Perkin Trans. 2 1997, 303. https://doi.org/10.1039/A604565K
Hilinski, E. F.; McGowan,
W. M.; Sears, D. F., Jr.; Saltiel, J.,
"Evolutions of Singlet Excited-State Absorption and Fluorescence of all-trans-1,6-Diphenyl-1,3,5-hexatriene in the Picosecond Time
Domain," J. Phys. Chem. 1996, 100, 3308. https://doi.org/10.1021/jp9529984
McGowan, W. M.; Hilinski,
E. F., "Competitive Bond Homolysis and
Intersystem Crossing in the Picosecond Time Regime. Photodissociation
of 9-Bromo- and 9-Chlorofluorene in Cyclohexane," J. Am. Chem. Soc.
1995, 117, 9019. https://doi.org/10.1021/ja00140a019
Gao, F.; Dharia, J. R.; McGowan, W. M.; Hilinski, E. F.; Johnson, K.
F.; Schlenoff, J. B., "New Fluors
for Radiation-Tolerant Scintillators," Mater. Res. Soc. Symp. Proc. 1994, 348, 173. https://doi.org/10.1557/PROC-348-173
Tate, K. L.; Hilinski, E.
F.; Foster, S. C., "Angle-Dependent Laser-Induced Voltages in
Room-Temperature Polycrystalline Wafers of YBa2Cu3O7-x,"
Appl. Phys. Lett. 1990, 57, 2407. https://doi.org/10.1063/1.103860
Schmidt, J. A.; Hilinski,
E. F., "Concurrent Pump-Probe and Streak Camera Measurements with a Single
Mode-Locked Nd:YAG Laser. A
Picosecond Absorption/Emission Spectrometer," Rev. Sci. Instrum. 1989, 60, 2902.
https://doi.org/10.1063/1.1140626
Mecklenburg, S. L.;
Hilinski, E. F., "Picosecond Spectroscopic Characterization of the
9-Fluorenyl Cation in Solution," J. Am. Chem. Soc. 1989, 111,
5471. https://doi.org/10.1021/ja00196a066
Schmidt, J. A.; Hilinski,
E. F., "Evolution of Electronically Excited Triphenylmethyl
Radical. Picosecond Preparation-Pump-Probe Spectroscopic Experiments," J.
Am. Chem. Soc. 1988, 110, 4036. https://doi.org/10.1021/ja00220a052
Schilling, C. L.; Hilinski, E. F., "Dependence of the Lifetime of the Twisted Excited Singlet State of Tetraphenylethylene on Solvent Polarity," J. Am. Chem. Soc. 1988, 110, 2296. https://doi.org/10.1021/ja00215a048