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Synthesis and Properties of Tetracyclopenta  def, jkl, pqr, vwx  tetraphenylene Tobe Lab. Kenta Ohtsuka.

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Presentation on theme: "Synthesis and Properties of Tetracyclopenta  def, jkl, pqr, vwx  tetraphenylene Tobe Lab. Kenta Ohtsuka."— Presentation transcript:

1 Synthesis and Properties of Tetracyclopenta  def, jkl, pqr, vwx  tetraphenylene Tobe Lab. Kenta Ohtsuka

2 Contents 1. Introduction -Singlet biradical 2. Results and discussion 3. Conclusion 4. Next plan

3 Singlet Biradical UHF/6-31G*//UB3LYP/6-31G* and Yamaguchi scheme Yamaguchi, K. Chem. Phys. Lett. 1975, 33, 330. n HOMO, n LUMO ; occupation numbers of HOMO or LUMO biradical character : y = 0 Fabian, J. et al. Angew. Chem. Int. Ed. 1989, 28, 677. closed shellsinglet biradical open shell y = 1 0 < y < 1 一重項ビラジカル 閉殻 開殻

4 h h ’ Two-Photon Absorption of Moderate Singlet Biradical  ; second hyperpolarizability K ab ; exchange integral U ; effective coulombic repulsion energy R BA ; distance between radical-sites K ab = y  [a.u.] U = 0.1, K ab = 0.001U = 0.1 Nakano, M. et al. Phys. Rev. Lett. 2007, 99,

5 o-quinodimethane p-quinodimethane Chase, D. T. et al. Angew. Chem. Int. Ed. 2011, 50, Shimizu, A.; Tobe, Y. Angew. Chem. Int. Ed. 2011, 50, Shimizu, A. et al. Angew. Chem. Int. Ed. 2013, 52, in press. Aaron, G. F. et al. Org. Lett. 2013, 15, 1362  Aromatic Stabilization Energy (ASE)

6 Indenofluorene Derivatives Chase, D. T. et al. Angew. Chem. Int. Ed. 2011, 50, Shimizu, A.; Tobe, Y. Angew. Chem. Int. Ed. 2011, 50, Shimizu, A. et al. Angew. Chem. Int. Ed. 2013, 52, in press. Aaron, G. F. et al. Org. Lett. 2013, 15, 1362  S-T gap (kJ/mol)HOMO (eV)LUMO (eV)H-L gap (eV)Biradical character (%) 1a a a a

7 Aromatic Stabilization Energy (ASE)

8 Chase, D. T. et al. Angew. Chem. Int. Ed. 2011, 50, Shimizu, A.; Tobe, Y. Angew. Chem. Int. Ed. 2011, 50, Shimizu, A. et al. Angew. Chem. Int. Ed. 2013, 52,1  5. Aaron, G. F. et al. Org. Lett. 2013, 15, 1362  D Structure 2D Structure

9 Hückel’s rule : Hückel's rule estimates whether a planar ( ヒュッケル則 ) ring molecule will have aromatic properties. A cyclic ring molecule follows Hückel's rule when the number of its  -electrons equals 4n+2 (n is zero or any positive integer)

10 COT(cyclooctatetraene ) Derivatives Einstein, F. W. B. et al. Chem. Commun. 1981, 526  528. Osuka, A. et al. J. Am. Chem. Soc. 2006, 128, Iyoda, M. et al. J. Am. Chem. Soc. 2010, 132,

11 Results and Discussion

12 Synthesis of 14 Hellwinkel, D. et al. Liebigs Ann. Chem. 1977, 1013  1025.

13 Variable-Temperature 1 H NMR Measurements H

14 S-T gap (kJ/mol) a HOMO (eV)LUMO (eV)H-L gap (eV) b Biradical character (%) c Quantum Chemical Calculations a S-T gap is calculated on the basis of the triplet energy that D 4h symmetrical structure is optimized by UB3LYP/6-31G*and singlet energy that D 2h symmetrical structure is optimized by RB3LYP/6-31G*. b H-L gap is calculated on the basis of the RB3LYP/6-31G* c Biradical character is calculated on the basis of the UHF/6-31G*//RB3LYP/6-31G*

15 Cristal Structure of 14 ・ Thetetracyclopenta[def,jkl,pqr,vwx]tetraphenylene core is planar and the mesityl groups form a large dihedral angle of  with the backbone. 信末 俊平, 博士論文, 2013.

16 (1.33 Å)(1.54 Å)(1.20 Å) Bond Length single bond > double bond > triple bond Bond Length of 14 信末 俊平, 博士論文, Å = m

17 NICS Value NICS (nucleus-independent chemical shift) The barometer that represents an effect of point’s shielding that is placed in the center of the ring. In this method, negative NICS values indicate aromaticity and positive values antiaromaticity. 信末 俊平, 博士論文, GIAO-RHF/6-31G*// RB3LYP/6-31G* UHF/6-31G*// UB3LYP/6-31G* GIAO-RHF/6-31G*// RB3LYP/6-31G* UHF/6-31G*// UB3LYP/6-31G*

18 Conclusions ・ Tetracyclopenta[def,jkl,pqr,vwx]tetraphenylene was synthesized. This compound showed biradical characters and antiaromatic because it has an inner 8  (COT) and an outer 20  conjugated cyclic systems. ・ X-ray crystallographic analysis of 14 shows that it adopts a D 2h symmetric structure.

19 ・ Synthesis of 15 ・ Properties of biradical character ・ Effect of curved structure Next Plan top view side view spin density 3D structure

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23 o-QDM derivatives p-QDM derivatives Shimizu,A.,; Tobe,Y. Angew. Chem. Int. Ed. 2011, 50, 6906  6910.

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25 Application of Two-Photon Absorption ① Two-photon Photodynamic Therapy By using two-photon absorption, long-wavelength light that is less susceptible to scattering and not absorbed by healthy cells can be used for excitation and can be performed photodynamic therapy to the deep part of other than the surface. ② Microfabrication Stereoscopic sulptures can be made at the level of sub-micrometer by controlling the three-dimensional location of the polymerization photocurable resin.


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