This presentation has been moved. To view this presentation, please visit http://pubs.acs.org/iapps/liveslides/pages/index.htm?mscNo=jz300577e The Effect of the π-Electron Delocalization Curvature on the Two-Photon Circular Dichroism of Molecules with Axial Chirality Herein we report on the theoretical-experimental study of the effect of curvature of the π-electron delocalization on the two-photon circular dichroism (TPCD) of a family of optically active biaryl derivatives (S-BINOL, S-VANOL, and S-VAPOL). The comparative analysis of the influence of the different transition moments to their corresponding TPCD rotatory strength reveals an enhanced contribution of the magnetic transition dipole moment on VAPOL. This effect is hereby attributed to the additional twist in the π–electron delocalization on this compound. TPCD measurements were done using the double L-scan technique in the picosecond regime. Theoretical calculations were completed using modern analytical response theory, within a time-dependent density functional theory (TD-DFT) approach, at both, B3LYP and CAM-B3LYP levels, with the aug-cc-pVDZ basis set for S-BINOL and S-VANOL, and 6-31G* for S-VAPOL. Solvent effects were included by means of the polarizable continuum model (PCM) in CH2Cl2.

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. 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 1

2. Motivation
The understanding of chiral molecules
with major relevance in
biology, pharmacology, catalysis, nanote
chnology, optics and photonics.
Limitations of ECD:
• Dark in the far UV.
Advantages of TPCD:
• Allows access into an unexplored
spectral UV region.
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3. Theoretical-Experimental Approach
TPCD was theoretically TPCD was revisited and
predicted in 1975. expanded in 2006.
Double L-scan Technique
J. Chem. Phys. 1975, 62, 1006. //J. Chem. Phys. 1975, 63, 1348. Opt. Lett. 2008, 33, 2958.
J. Chem.Phys., 2006 , 125, 064113. Chem. Eur. J. 2010, 16, 3504
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4. Definition of TPCD
2
TPCD L R 4 2 g 2 NA TPCD
2 2 3 2
R0 f 0f
15 c0 4 0
1
TPCD TI TI TI
R 0f 0f bB
1 1 0f bB2 2 0f bB 3 3 0f
1
B1TI 0f 3
M p ,0 f 0f P p*,0 f 0f
1
TI
B2 0f 3
T ,0 f
0f P p*,0 f 0f 2
2
TI 1
B3 0f 3
M p ,0 f 0f P p*,0 f 0f
J. Chem. Phys. 1975, 62, 1006. //J. Chem. Phys. 1975, 63, 1348.
J. Chem.Phys., 2006 , 125, 064113.
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5. S-BINOL, S-VANOL and S-VAPOL
( -electron delocalization direction)
TPCD was measured on these three compounds to understand the effect of
conjugation direction and extension.
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6. Two-Photon Absorption (TPA) and
TPCD spectra
S-BINOL
S-VANOL
S-VAPOL
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7. Contributions to RTPCD from the
different transition moments
Electric transition quadrupole
moment contributions
Magnetic transition dipole
moment contributions
J.C.S. Faraday II, 1980, 76, 1249.
Phys. Rev. A 2007, 75, 032518.
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8. F. E. Hernandez A. Rizzo
C. Diaz N. Lin
C. Toro R. Passier
Grant Number CHE-0832622
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