Presentation jpc letters eh1 cd1
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1 The Effect of the π-Electron Delocalization Curvature on the Two-Photon Circular Dichroism of Molecules with Axial Chirality Carlos Diaz, † Na Lin, ‡ , § Carlos Toro, † Remy Passier, † Antonio Rizzo, ∥ and Florencio E. Hernndez † , ⊥ † Department of Chemistry, University of Central Florida ‡ State Key Laboratory of Crystal Materials, Shandong University, China §Department of Chemistry, University of Tromsø, N-9037 Tromsø, Norway ∥ Consiglio Nazionale delle Ricerche, Istituto per i Processi Chimico Fisici, Italy ⊥The College of Optics and Photonics, CREOL University of Central J. Phys. Chem. Lett. 2012, 3, 1808-1813
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Transcript of Presentation jpc letters eh1 cd1
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The Effect of the π-Electron Delocalization Curvature on the
Two-Photon Circular Dichroism of Molecules with Axial Chirality
Carlos Diaz,† Na Lin,‡,§ Carlos Toro,† Remy Passier,† Antonio Rizzo,∥ and Florencio E.
Hernandez†,⊥
† Department of Chemistry, University of Central Florida
‡ State Key Laboratory of Crystal Materials, Shandong University, China
§Department of Chemistry, University of Tromsø, N-9037 Tromsø, Norway
∥ Consiglio Nazionale delle Ricerche, Istituto per i Processi Chimico Fisici, Italy
⊥The College of Optics and Photonics, CREOL University of Central Florida
J. Phys. Chem. Lett. 2012, 3, 1808-1813
Motivation
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The understanding of chiral molecules with major relevance in biology, pharmacology, catalysis, nanotechnology, optics and photonics.
Limitations of ECD:• Dark in the far UV.
Advantages of TPCD:• Allows access into an unexplored
spectral UV region.
Theoretical-Experimental Approach
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TPCD was theoretically predicted in 1975.
J. Chem. Phys. 1975, 62, 1006. //J. Chem. Phys. 1975, 63, 1348.J. Chem.Phys., 2006 , 125, 064113.
TPCD was revisited and expanded in 2006.
Double L-scan Technique
Opt. Lett. 2008, 33, 2958.Chem. Eur. J. 2010, 16, 3504
Definition of TPCD
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2 2 0 0230 0
0 0 1 1 0 2 2 0 3 3 0
2 24
15 4
ATPCD L R TPCDf f
TPCD TI TI TIf f f f f
g NR
c
R b B b B b B
,0 *,01 0 0 03
,0 *,02 0 0 03
,0 *,03 0 0 03
1
1
2
1
TI p f p ff f f
TI f p ff f f
TI p f p ff f f
B M P
B T P
B M P
J. Chem. Phys. 1975, 62, 1006. //J. Chem. Phys. 1975, 63, 1348.J. Chem.Phys., 2006 , 125, 064113.
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S-BINOL, S-VANOL and S-VAPOL (-electron delocalization direction)
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TPCD was measured on these three compounds to understand the effect of conjugation direction and extension.
Two-Photon Absorption (TPA) and TPCD spectra
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S-BINOL
S-VANOL
S-VAPOL
Contributions to RTPCD from the different transition moments
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Electric transition quadrupolemoment contributions
Magnetic transition dipolemoment contributions
J.C.S. Faraday II, 1980, 76, 1249.Phys. Rev. A 2007, 75, 032518.
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Conclusions
The magnetic transition dipole moment contribution to is
strongly enhanced by the twist in -electron delocalization in
conjugated chiral molecules.
Acknowledgments
F. E. Hernandez A. Rizzo
C. Diaz N. Lin
C. Toro R. Passier
Grant Number CHE-0832622
