Tobe Lab.Kenta Ohtsuka

Structures and Properties of Bowl-Ｓhaped Compounds

Contents

1.Singlet Biradical2. Biradicaloid with 2D and 3D Geometry3. Bowl-shaped Compounds: Bucky Bowls -corannulene -sumanene4. POAV: A Measure of Bowl Depth5. Dynamic Process: Bowl-to-Bowl Inversion6. Theoretical Study for My Target Compound7. Conclusions and Outlook

o-quinodimethane p-quinodimethane

Aromatic Stabilization Energy (芳香族安定化エネルギー)

Singlet Biradical

S-T gap (kJ/mol) HOMO (eV) LUMO (eV) H-L gap (eV) Biradical character (%)

1a 78.5 -5.22 -2.61 2.61 30.2

2a 53.9 -5.11 -2.85 2.26 32.5

Shimizu, A.; Tobe, Y. Angew. Chem. Int. Ed. 2011, 50, 6906.

Chase, D. T. et al. Angew. Chem. Int. Ed. 2011, 50, 11103 -11106.

R

R

1a : R = H

1b : R = Si

R R

2a : R = H

2b : R =

Aromatic Stabilization Energy (ASE)

UHF/6-31G*//UB3LYP/6-31G* and Yamaguchi schemeYamaguchi, K. Chem. Phys. Lett. 1975, 33, 330.

nHOMO, nLUMO; occupation numbers of HOMO or LUMO

21

21

T

Ty

2

LUMOHOMO nnTbiradical character :

1a

2a

closed shell open shell

gS1

uS1

gS2

hn

hn’

hn’

Properties derived from singlet biradicalTwo-Photon Absorption Two-photon absorption is the simultaneous absorption of two photons of identical or different frequencies in order to excite a molecule from one state (usually the ground state) to a higher energy electronic state.

GM = 10−50 cm4 s photon−1 molecule−1

2

2

2

2

2

4

)1(1

1

)1(1

121

)1(4

yyUK

y

U

R

ab

BA

g ; second hyperpolarizabilityKab ; exchange integral U ; effective coulombic repulsion energyRBA ; distance between radical-sites

t-Bu

t-Bu t-Bu

t-Bu

bis(phenylethynyl)zethrene(y = 0.41) rubrene

67 GM>1100 GM

g [

a.u

.]

y

Kab = 0.01 0.005 　　　　　 0.001

Motivation

4 765

2D 3D

RR

3a : R = H

3b : R =

(mesityl group)

Aaron, G. F. et al. Org. Lett. 2013, 15, 1362-1365.

4open shell closed shell

Motivation

5

open shell closed shell

Motivation

6

open shell closed shell

7

open shell closed shell

Bucky Bowlsthe generic name of the bowl-shaped conjugated compounds corresponding to substructure of fullerenes or the cap structure of the carbon nanotube.

corannulene sumanene

S S

S

Imamure, K.; Takamiya, K. et al. Chem. Commun., 1999, 1859-1860.

carbonnanotube

fullerene

Corannulene Corannulene is a polycyclic aromatic hydrocarbon with chemical formula C20H10. The compound consists of a cyclopentane ring fused by five benzene rings. It is of scientific interest because it can be considered as a fragment of fullerene.

fullerenecorannulene

Synthesis of Corannulene

Anna, M. B. et al. Org. Process Res. Dev. 2012, 16, 664-676.

Cl

1. Mg, 1.5 M Et2O 3 h, 35 C

O OMe

OMe2., 2h

OH

MeO

OMe 0.81 M H2SO4/AcOH, r.t.(COCl)2 (1.2 equiv)AlBr3 (2.1 equiv)

0.24 M CH2Cl2, 8h-38 C to -15 C

O O O O

+

85% 71%

73%

Girard's Reagent T (1.2 equiv)AcOH, 2 h, 40 C

O N O O

+

HN

O

N

85%

3-pentanone (8 equiv)KOH (8 equiv)

0.32 M MeOH, 2 h, r.t.

O

OHNBD (8 equiv)

0.43 M Ac2O, 3 d, 140 C

73%

Br

Br

Br

Br

Br Br

BrNBS (11.7 equiv)AIBN (0.04 equiv)

0.20 M C6H5Cl, 23 h, h, 400 mbar

60%

NaOH aq (9.5 equiv)0.11 M iPrOH, 1 h, 80 C

Br

Br

Br

Br

HCOOH (10 equiv)Et3N (10 equiv)5% Pd/C

0.13 M 3-picoline, 16 h, 110 C

88%79%

Sumanene• sumanene is a polycyclic aromatic hydrocarbon and of scientific interest because the compound can be considered a fragment of fullerene. • The core of sumanene is a benzene ring and the periphery consists of six-membered rings and five- membered rings. • Sumanene has three sp3 hybridized carbon atoms at the benzylic positions.

sumanene fullerene

benzylic position

t-BuOK (2.0 eq)n-BuLi (2.0 eq)Br(CH2)2Br (1.0 eq)

THF (-40 C), 90 minCuI (2.0 eq)-78 C to r.t., 4 h

+

anti syn

RuCl

ClPCy3

PCy3Ph

under ethylene gastoluene, 0 C to r.t., 24 h

H

H

H

H

H

HDDQ (5.9 eq)

toluene, rfx., 3 h

Synthesis of Sumanene

t-BuLi (3 eq)

THF-d8

3LiexcessMe3SiCl

SiMe3

Me3Si SiMe3

benzylic position

Sakurai, H.; Daiko, T. et al. J. Am. Chem. Soc. 2005, 127, 11580-11581.

Crystal Packing of Sumanene

4.5×10-2 cm2V-1s-1 (parallel to π-bowl stacking axis)

3.86 Å

0.49×10-2 cm2V-1s-1 (perpendicular to π-bowl stacking axis)

Amaya, T.; Seki, S. et al. J. Am. Chem. Soc. 2009, 131, 408-409.

POAV (P-Orbital Axis Vector) POAV angle is defined as θσπ-90, which indicates the extent of the pyramidalization.For planar compound, POAV angle is 0.

POAV = 0 POAV = 0

1D Structure 2D Structure

Amaya, T.; Sakane, H. et al. Pure Appl. Chem. 2010, 82, 969–978.

POAV =

R

R

1a : R = H

1b : R = Si

POAV = 8.4

Andrzej, S. et al. J. Am. Chem. Soc. 1996, 118, 339-343.

POAV = 8.7

Amaya, T.; Sakane, H. et al. Pure Appl. Chem. 2010, 82, 969–978.

Corannulene Sumanene

BD = 0.89 Å BD = 1.15 Å

Fullerene

POAV = 11.6

Hindy, E. B. et al. J. Am. Chem. Soc. 2002, 124, 8870-8875.

rim

hub

vertex

rim-quat

BD (bowl depth) : Bowl depth is distance between the plane of the hub benzene ring and the aromatic carbon rim .

POAV of My Compound

BD(Bowl Depth) of My Compound

0.84 Å

POAV = 5.4

POAV = 7.6

corannulene

Bowl-to-Bowl Inversion of Corannulene

• The curvature stems from the presence of a five-membered ring centered among six-membered rings.• Corannulene represents bowl-to-bowl inversion　 and the energy is 8.63 kcal/mol (B3LYP/6-31G) (室温で 1秒間に 200,000回以上回転 )

Biedermann, P.U.; Pogodin, S. et al. J. Org. Chem. 1999, 64, 3655-3662.

= 8.63 kcal/mol

Bowl-to-Bowl Inversion of Sumanene

Amaya, T.; Sakane, H. et al. Pure Appl. Chem. 2010, 82, 969–978.

= 16.8 kcal/mol

• Bowl-to-bowl inversion energy barrier of sumanene : 16.8 kcal/mol(B3LYP/6-31G(d)) (室温で 1秒間に約 1回反転 )

Bowl-to-Bowl Inversion of My Compound

= 6.46 kcal/mol

• Bowl-to-bowl inversion energy barrier of My compound: 6.46 kcal/mol(B3LYP/6-31G(d))

Discussion

my compoundsumanenecoronene

DiscussionCorannulene

123

111

126

planar structure

122

114

123

bowl shaped structure

121

118

117

106

126

122

116

planar structure

123

121

115

108

124

121116

Bowl shaped structure

My compound

Conclusions・ Bucky bowls such as corannulene and sumanene showed bowl-to-bowl inversion with 8.63 kcal/mol, 16.8 kcal/mol respectively and my compound showed bowl- to-bowl inversion with 6.46 kcal/mol.

・ POAV, BD, and the barrier for the bowl-to-bowl inversion of my compound was estimated to be smaller than those of corannulene and sumanene.This may be affected by the number of five-membered rings and bond angle strain.

HO OH pyridine O

O

N O

O

N

NiCl2(dppp)

MeMgBr-Et2O

NBS, AIBN

O

O

O

O

O O

N2 N2 h CH3Li

diethylcarbamyl chloride

CCl4

PhLi, bromobenzene

benzeneBr Br

OAcAcO

AlCl3, Pd black

CS2

Ce(OTf)4

TsNHNH2

OO

O

OH

O

HO

OO

CF3COOHO

MesMgBr

Et2OMes

OH

Mes

HO

Mes MesSnCl2

CH2Cl2

NaBrO3-HBr

Outlook

Packing of Corannulene

Application of Two-Photon Absorption①Two-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 .

②MicrofabricationStereoscopic sulptures can be made at the level of sub-micrometer by controlling the three-dimensional location of the polymerization photocurable resin .