Frontiers Workshop

Design and Synthesis of a molecular motor incorporating insulating

fragments

Guillaume Vives

PhD Supervisors : Gwénaël Rapenne and Jean-Pierre Launay

C. Joachim et al, Science 1998 , 281, 531-533

STM Images on Cu (100)

ESQC Calculations

Motionless

In rotation

ROTATION OF DECACYCLENE

A non-directional rotor

hexa-tert-butyl decacyclene

3

PRINCIPLE OF THE ROTARY MOTEUR

e-

_+

EG

EG

EG

EG

EG

Anode Cathode

Step 1

(Rotation of one fifth of turn)

_+

EG

EG

EG

EG

EG

Anode Cathode

Step 2

_+

e-

EG EG

Anode Cathode

EG

EG

EG

e-

Step 3

Desired behavior Unwanted mechanism

e-

+ _

EG

EG

EG

EG

EG

CathodeAnode

e- e-

+ _CathodeAnode

e-

EG

EG

EG

EG

EG

4

DESIGN

Stator : Tripodal ligand functionalized to be anchored to the surface. Rotor : Cp ligand with five rigid arms terminated by electroactive groups (EG) Insulating Spacers to prevent intramolecular electron transfer. Joint : Ruthenium atom

N

N

N

N

N

N

B

H

Ru

EG: Electoactive Group

Oxide Surface

EG

EG

EGEG

EG I

I

I

I I

I: Insulator

Four Parts :

5

GOAL MOLECULE

Four Parts :

Stator : Hydrotris(indazolyl)borate ligand

Rotor : Substituted Cp terminated by ferrocenyls

Insulator : trans Pt(II) complex

Joint : Ruthenium atom

L

Pt

Pt

PtPt

Pt

LL

L

L

LL

L

L

LFe

Fe

Fe Fe

Fe

NN

NN

NN

BH

RuL = PEt3

COOEt COOEtCOOEt

6-3,00E-06

-2,00E-06

-1,00E-06

0,00E+00

1,00E-06

2,00E-06

3,00E-06

4,00E-06

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1

E (V/ECS)

i(A

)

-3,00E-06

-2,00E-06

-1,00E-06

0,00E+00

1,00E-06

2,00E-06

3,00E-06

4,00E-06

5,00E-06

6,00E-06

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1

E (V/ECS)

i(A

)

INSULATING ROLE OF PLATINUM

- Electrochemical Study

Fe Fe

1

Pt

PEt3

PEt3Fe Fe

2

E1/2(1)

(V/CSE)

E1/2(2)

(V/CSE)

E1/2

(mV)

1 0,58 0,68 ~ 100

2 0,32 0,40 ~ 80

1

2

7

INSULATING ROLE OF PLATINUM

- Spectoelectrochemical Study

1

2

MM

ab RV

2/12/1maxmax

21005.2

Hush formula:

1 : Vab = 0,036 eV

2 : Vab = 0,025 eV

Parametre of electronic coupling :

8

INSULATING ROLE OF PLATINUM

DFT (BP86 / 6-31 G**) Geometry optimisation

Fe

FePt

PMe3

PMe3Fe

Fe

9

INSULATING ROLE OF PLATINUM

dxy dx2-y2

dz2

dxz dyz

HOMO (u)

LUMO (g)

2Vab

E

Fe --- Fe Ligand

Vab calculation: dimer splitting method

Fe Fex

y

dx2-y2 dxy

Overlaping between 3d orbital of Fe and the bridging ligand

E3d(Fe) E(u) E(g) E (eV) Vab (eV)

1 -10,500 -10,767 -10,903 0,136 0,068

1 -11,000 -11,117 -11,272 0,155 0,077

1 -11,500 -11,390 -11,649 0,259 0,129

2 -10,500 -10,849 -10,813 0,036 0,018

2 -11,000 -11,231 -11,186 0,045 0,022

2 -11,500 -11,522 -11,612 0,090 0,045

Energies of the orbitals and Vab of 1 and 2

~ Vab/3 with Pt

10

RETROSYNTHETHIC ANALYSIS

Ru

Fe

FeFe

Fe FeN

NN

NBH

NN

PtPt

Pt Pt

PtL

L

L

L

L

L

L

L

LL

L=PEt3 PtCl

PEt3

PEt3 Fe

B

N

N

N

N

N

N

H

H

H

H

H H

Ru

Br

N

N

N

N

B

H

N

N

Br Br

BrBr Ru+

Pt

PEt3

PEt3 Fe

+

11

SYNTHESIS OF THE RUTHENIUM CENTER

Br

Br

Br

BrBr

Br HTIPS

TIPS

TIPS

TIPS TIPS

TIPSA

CuI, Pd(PPh3)4Et2NH, THF

BuLi

NBS THF

80 %

BrTIPS

TIPS

TIPS

TIPS TIPS

55 %

Ru

OCCO

Br

Ru

B

N

NN

N

N

N

H

Ru3CO12 KTIBTIPS

TIPS

TIPS

TIPS TIPS

TIPS

TIPS

TIPS

TIPS TIPS71 % N

N

N

N

B

H

N

N

Ru

H

H

H H

H

TBAF

Toluene THF

16 %

THF

61 %

12

SYNTHESIS OF A MODEL MOTOR

Ru

Fe

FeFe

Fe FeN

NN

NBH

NN

PtPt

Pt Pt

PtPEt3

Et3P

Et3P

PEt3

PEt3

Et3P

Et3P

PEt3

PEt3Et3P

N

N

N

N

B

H

N

N

Ru

Fe

Pt

PEt3

PEt3

Cl

H

H

H H

HCuI, Et2NH, THF

41 %

Fe

PtCl2(PEt3)2

CHCl3, NHEt286 %

Pt Cl

PEt3

PEt3Fe

Pt fragment synthesis:

Connection

13

CARACTERISATIONS

1.01.01.51.52.02.02.52.53.03.03.53.54.04.04.54.55.05.05.55.56.06.06.56.57.07.07.57.58.08.0

a-e b c d

o m

Cp

Cp subs Cp subsCH2

CH3

1H RMN (CD2Cl2) 500 MHz

31P RMN

2244668810101212141416161818202022222424

195Pt {31P} RMN

L

Pt

Pt

PtPt

Pt

LL

L

L

LL

L

L

LFe

Fe

Fe Fe

Fe

NN

NN

NN

BH

RuL = PEt3a

b

cd

e

o m

JPt-P(trans) = 2374 Hz

14

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1

Fe(II) / Fe(III)

5 e-

Ru(II) / Ru(III)

1 e-

CARACTERISATIONS

Electrochemistry : CV : CH2Cl2, nBu4PF6 0.1 M, 100 mV.s-1

E1/2 (V/SCE) Fe Ru

0.31 0.60

0.52 0.82NN

NN

NN

BH

Ru

Fe

Fe

FeFe

Fe

L

Pt

Pt

PtPt

Pt

LL

L

L

LL

L

L

LFe

Fe

Fe Fe

Fe

NN

NN

NN

BH

RuL = PEt3a

b

cd

e

o m

15

FUNCTIONALISED STATOR FOR OXIDE SURFACES

COOH

NH2

COOEt

NH2SOCl2, EtOH

98%

COOEt

NHN1) Ac2O, AcOK

isoamylnitriteToluene

2) HCl

64%

KBH4, 180°C

72%

NN

B

EtOOC

NN

COOEt

NN

COOEt

H

K

Ligand synthesis

Model Ru complex

Ru

N NN

KTp4BoCO2Et

NN

NN

NN

BH

Ru

COOEt COOEtCOOEt

MeMe

Me

PF6

CH3CN, DMF

16

FIRST MOLECULAR MOTOR

TIPS

TIPS

TIPSTIPS

TIPS

Ru

OCCO Br N

N

NN

NN

BH

Ru

TIPS

TIPS

TIPSTIPS

TIPS

NN

NN

NN

BH

Ru

H

H

HH

H

KTp4BoCO2Et

ACN, DMFMW

TBAF, THF 5% H2O

COOEt COOEtCOOEt COOEt COOEt

COOEt

17%54%

L

Pt

Pt

PtPt

Pt

LL

L

L

LL

L

L

LFe

Fe

Fe Fe

Fe

L = PEt3NN

NN

NN

BH

Ru

COOEt COOEtCOOEt

Pt ClPEt3

PEt3Fe

CuI, Et2NH

35 %

17

PERSPECTIVES

18

AKNOWLEGMENTS

Groupe NanoSciences (CEMES)– Alexandre Carella– Stéphanie Sistach– Gwénaël Rapenne– Jean Pierre Launay– Christine Viala

LCC– Christine Lepetit

Frontiers Network

19

ATP SYNTHASE

A biological rotary motor :

J. E. Walker, Angew. Chem. Int. Ed., 1998, 37, 2308

The rotation of F1 is controled by the proton gradient through the membrane

20

SYNTHESIS OF THE ORGANOMETALLIC CORE

KTIB

Ru

OC COBr

Br

Br

Br

BrBr

Br

Br

Br

BrBr

BrRu

Br

Br

BrBr

Br

B

NN

NN

NN

H

Br2

98%

Ru3CO12

78% 30%

KTIB

B

NN

NN

NN

H

NN

H

KBH4, 220°C

80%

K

21

Fe

PtCl2(PEt3)2

CHCl3, NHEt286 %

Pt Cl

PEt3

PEt3Fe

Pt

PEt3

PEt3FeCuI, Et2NH

91 %

HHH

FIRST STRATEGY

Ru

Fe

FeFe

Fe FeN

NN

NBH

NN

PtPt

Pt Pt

PtL

L

L

L

L

L

L

L

LL

Br

N

N

N

N

B

H

N

N

Br Br

BrBr Ru Pd(PPh3)4Fe

Pt

PEt3

PEt3

ZnCl

+

Pt fragment synthesis:

Connection: