materiales orgánicos conductores - unamdepa.fquim.unam.mx/amyd/archivero/tomastorres6_27200.pdf ·...

Materiales Orgánicos Conductores

CNNCN

NC CN

S

S S

SN NNN

NNM

C

NCTCs

Metalomacrociclos

Materiales orgánicos

Metalomacrociclos

orgánicos conductores

Polímeros conjugadosFullerenos

Conducting Charge-Transfer ComplexesConducting Charge Transfer Complexes

S

S

S

STetrathiafulvene (TTF) 1973

CN

CN

NC

NC7,7,8,8-Tetracyanoquinodimethane (TCNQ)

1:1 Complex (crystallizes from acetonitrile)1:1 Complex (crystallizes from acetonitrile)

Displays metal-like conductivity over a wide temperature range(highest = 1.47 x 104 S/cm at 66 K; copper wire: = 6 x 105 S/cm at 298 K)

Complejos de transferencia de carga. TTF-TCNQ

CNNC

500 S 1 (TA)

NC CN

S

S S

S

= 500 Scm-1 (TA)

NC CN

“Orbitales Cristalinos”

Conductivity and Electronic StructureySolids: many bonded atoms, electronic states group into extended energy domains

BandsBand Structures:

Energy

nduc

tion

ban

“Crystalline Orbitals”

Energy gap: 0,5-1.5 eVEnergy gap > 3 eV

Fermi level

Empty levels

Con

du

Fermi level

Occupied levelsand

Occupied levels

alen

ce b

aM t l T C d ti it

Metal Semiconductor Insulator

Va Metal: T Conductivity

Semiconductor: T Conductivity

Conducting Charge-Transfer ComplexesConducting Charge Transfer Complexes

CNNC

e

CNNC

S S e S S

CNNC NC CN

SS SS

Mixed-valence salts (charge transfer is not complete)

It is basic!: Knowledge about the Red-ox potentials of donor and acceptor

Disposición eléctricamente conductorap

D+

D+ D+

A- A-

A-

D+

D D

A A-

A

D+

A-

D+

3,2-3,5 Å

DD+

D+ D+

AA- A-

A-

DD+

D D+

A A-

A-

D A-

D+

A- D

D+

D+

AA- A-

D+

D A A-

A D+

A-

D+A D+A- D+A D+A-

Aislante Semiconductor Conductor

DAD+A

Sales de valencia mixta

Disposición eléctricamente conductora

S

S

S

SMe

Me

Me

MeClO4

Electrocristalización

Moléculas dadoras de electronesMoléculas dadoras de electrones

S S SMe Me S S

S

S

S

S

TTF

Se

Se

Se

SeMe Me

MeMeTMTSF

S

S

S

S

S

S S

SBEDT-TTF (ET)TTF TMTSF BEDT-TTF (ET)

S SS S SO O Se SMe S

S SS

MDT-TTF

S SO OBEDO-TTF (BO)

Se SMe S

DMET

S

S

S

S S

S

Me

Me Se

Se

Se

Se S

SS

S

Se

Se

Se

Se S

SMe

Me

SMe

S,S-DMBEDT-TTF

SS

BEDT-TSF (BETS)

SMe

DMEDT-TSF

Moléculas aceptoras de electronesMoléculas aceptoras de electrones

NC CN

R1 R3 R1 R3

NCN

R2 R4

CNNCN

R2 R4

NC

TCNQ DCNQI

SSSS

S

S

SM

SS

S

S

S

SS

M(d it) n

C60

Buckminsterfullerene

M(dmit)2n

M = Ni, Pd, Pt

Efectos de la disminución de la TemperaturaEfectos de la disminución de la Temperatura

•Deformación de Peierls: Paso de Metal a semiconductor o aislante (deformación de la red)semiconductor o aislante (deformación de la red) al disminuir la T

•Superconductividad: Aumento drástico de la d i id d l di i i l T ( d ió d lconductividad al disminuir la T (reducción del

número de fonones o amplitud de las vibraciones d l d l i l f ó )de la red + acoplamiento electron-fonón)

Superconductores inorgánicos y orgánicos

Tl2Ba2Ca2Cu3O10

p g y g

100Tl2Ba2Ca2Cu3O10

RbTl C

K) NbN

ET Cu[N(CN) ]Cl

Rb3C60

RbTl2C60

10T (K

Hg

Nb

ET AuI-ET2Cu(NCS)2

-ET2Cu[N(CN)2]Cl

g

-ET2IBr2

-ET2AuI2

11900 1920 1940 1960 1980 2000

-ET2I3

1900 1920 1940 1960 1980 2000Año

Conducting Polymers: The BasicsConducting Polymers: The BasicsWhat is a polymer?A polymer is a chemical comprised of repeating molecules

with the same chemical structure.

What is conductance?Conductance is the ability of a material to carry electricalConductance is the ability of a material to carry electrical

charge.So what is a conducting polymer?So what is a conducting polymer?A conducting polymer joins these things to yield an organic

material able to take on properties normally seen only inmaterial able to take on properties normally seen only in metals.

Conducting PolymersConducting Polymers

P l ith l j t d h i i l t i d t ( 10 9 S/ )Polymers with polyconjugated chains: isolators or semiconductors ( = 10-9 S/cm)

Ti(IV)Polyacetylene (PA)

Ziegler-Natta-Shirikawa

H H( )

x n

cis-PA = 10-9 S/cm

trans-PA = 10-5 S/cm

AsF5

(halogens, FeCl3 , XeOF4 , ...)

“Doped” all-(E)-PA (s = 10-2 – 10-3 S/cm)

(metallic sheen; unstable: in air, conductivity drops within hours)

“Doping” ProcessDoping Process

R d ti b t d i t d j t d tRedox reaction between doping agent and conjugated system(i. e. polymer is oxidized to a polymeric cation, doping agent is the counterion)

Also, electrons hopping from chain to chain

Conducting Polymers

2 +

+n

3 I2n

+ 2 I3-

Molecular versus Band Models

M. Lögdlund et al.E

1

2 3

4 7

EE (eV)

56 8

El t

n

LUMO

Electronaffinity

BandgapHOMO

Ionizationpotential

Bandgap

potential

Electronic Structure

E Localized (l) level

Delocalized (d) level

- Key role in determining the optical propertiesKey role in determining the optical properties

Nobel Prize in Chemistry 2000

“For the Discovery and Development of Conductive Polymers”

Hid ki Shi kHideki ShirakawaUniversity of Tsukuba

Alan HeegerUniversity of California

t S t B b

Alan MacDiarmidUniversity of

P l iat Santa Barbara Pennsylvania

Conjugated Polymers

n Sn

Nnn

Trans-polyacetylene (t-PA)

n

Polythiophene (PT)

H

Polypyrrole (PPY)

n

Poly(p phenylene) (PPP)

n

Poly(p phenylenevinylene) (PPV)Poly(p-phenylene) (PPP) Poly(p-phenylenevinylene) (PPV)

NH NH N N

ny 1-y

Polyaniline (PAN)

Conducting Polymers

Relative low influence of the temperature

Electron-Phonon Coupling

EExcitation Doping

E

LES +1

E

Relaxationeffects

LES +1

Absorptioneffects

Emission IonizationRelaxationeffects

GS GS

Q Q

Chemical Doping of Conjugated Polymers

CB

Radical-cation / Polaron VB

+

Dication / Bipolaron

++++

Electronic Structure

SS

SS

SS

EE

LL L

POL2BIP2

BIP1

HH H

POL1

Polaron BipolaronNeutral

J. Cornil et al., Adv. Mater. 8, 447 (1996)

Optical Properties

SS

SS

SS

b. u

nits

)

Neutral

Bipolaron

tens

ity (a

rb

Polaron

Int

Energy (eV)600 800 1000 1200 1400 1600 1800 2000

Energy (nm)

J. Guay et al.Chem. Mater. 4, 1097 (1992) Electrochromic windows, sensors

Advantages

Combination of properties

M l Pl iMetals Plastics

Hi h d ti it Li htHigh conductivity LightnessEase of processing (spin coating)Low costLow costTailored synthesis

- Low oxidation potential (doping by I2, AsF5, SbF5, …)

Hi h l t ffi it (d i b Li N K )- High electron affinity (doping by Li, Na, K, …)

- Stability of the backbone not affected upon doping

Applications

- Batteries

El t t ti ti- Electrostatic coatings

S

Baytron P (Bayer) / Orgacon (AGFA)

S

O O

nn

SO3-

PEDOT PSS

- Electromagnetic shielding

- Electrochromic windows

- Actuators (Artificial muscles)

Ftalocianinas NFtalocianinas

NN

NN

N

N

NM

N

N

N

N

N

NMetallo- N

N

N FreeN

NN

N N

NM

Metallophthalocyanine

(PcM)N

NN

N

N

N

NH

H

Free Phthalocyanine

(PcH2)

N N

Q BandQ-Band

B or Soret-Band

Soret and Q bands

Ftalocianinas

MetallophthalocyaninesMetallophthalocyaninesMetallophthalocyaninesMetallophthalocyanines

NN

N

NNN

N

N

NM

N

UV-visible Spectra of Phthalocyanines and Analogues

1 P

NaphthalocyanineSubphthalocyanine

0 6

0.8

banc

e

Pc

0 2

0.4

0.6

Abs

orb

0

0.2

260 360 460 560 660 760260 360 460 560 660 760

Wavelength (nm)

Organization of Phthalocyanines in Condensed Phases

Si

N

NN N

N

OOO

O

OH

Liquid Crystals

OH

Si

OO

NN

NN

OO

LB FilmsN NN

C10H21H21C10

C10H21C10H21

LB-Films

NN

N

N

N M

C10H21C10H21

COOHHOOCLangmuir-Blodgett filmLangmuir film

Properties of Phthalocyanines. Applications

C d i P iSemiconducting materials

Conducting Properties Selective gas sensorsElectrochemical SensorsField Effect Transistors

Optical PropertiesPhotovoltaic Devices

Optical Properties Optical Recording DataPhotodynamic Therapy (PDT)

Nonlinear Optical Properties Frecuency DoublersOptical Limitersp

Conducting Metallo-Macrocyclesg y

N

N

NN

NNM

N

N

N

NM

N

N

N

NM

N

N

Phthalocyanine TetrabenzoporphyrinTetraphenylporphyriny yy y

Pc TPP TBP

Conducting Polymeric Metallo-Macrocyclesg y y

M M ML L L

PorphyrinPorphyrinor

Phthalocyanine

M M ML L L

M M ML L L

Conducting Polymeric Metallo-Macrocyclesg y y

NN

N

NN

N

N

N

N

N

NN

NM

N

N

NN

NMN N

CNCN CNN NN N N N CNCN CNN NN N N N

Aplications based on Conducting Properties ofAplications based on Conducting Properties of Phthalocyanines

Gas SensingArtificial Tongues and Noses

Gas Sensing

N NN

C10H21H21C10

C10H21C10H21

NN

N

N

N M

C10H21C10H21

Langmuir-Blodgett film COOHHOOC

Concept of electronic nose

“Inst ment fo med b an a a of chemical senso s ith“Instrument formed by an array of chemical sensors with cross-sensitivity coupled to a pattern recognition

software able to discriminate complex gases”.

First levelFirst level

Second levelSecond levelPCAPCAt /s

datos

resistenciaepitelioolfatori

corteza

bulboofatorio

cerebro

SoftwareSoftware

Thi d l lThi d l l

****

****

**

****

**

**Aceite CAceite C

Aceite BAceite B Aceite AAceite Anariz humana nariz electrónica

sensores

apolfatorio

Third levelThird levelNeural NetworkNeural Network

6

7

electrodos

material ibl

bulbofibras nerviosas

electrónica

moléculas de olor

sensibleneuronascilios

Electroactive sensing materialsElectroactive sensing materials

Development of a hybrid array of voltammetric sensors formed by electrodes chemically modified with materialsformed by electrodes chemically modified with materials

with rich electrochemical activity

Rare earth Bis-phthalocyanines Perylenes Conducting polymers

O O

N NRR R

O O

Ftalocianinas como Materiales Moleculares

N N

NN

N

N

NH

H NN

N

N

NM2- N

NN

N

N

N

N

N N

N

NN

N

N

Ftalocianinalibre (PcH2)

Forma aromática de la ftalocianina

Metaloftalocianina(MPc)

Propiedades físicas no convencionales (semiconductoras, ópticas...) Estabilidad térmica, química y ópticaVersatilidad de su estructura química modulación de sus propiedades

Síntesis de ftalocianinas

CuCN/DMFR

Br

Br

NH3

MeOH/MeONaR

CN

CNR N

NH

NH

TT

TCuCN/DMF ROH/DBNMX disolvente

NH2

R

N

R RR

N

R'

N

R'

NN

N

N

N

NM N

NHN

N

N

HN

NH3O+

MXN

NN

N

N

M

R

N

N

N

R RR

N

N

HNMX

R'

N

N

N

R'

Espectro UV-vis de las ftalocianinas

N

N

N N

N

N Banda QN

NN

N

N

N

NM N

NN

N

N

N

NH

HBanda Q

Banda B o Soret

Síntesis de ftalocianinas asimétricas

CN CN

R

R

+

CN

CN

R CNR

R HN

N

NH

N N

N

NH2

N

NH2

+

RR HN

NN

NH

N

NHR

NHR

R

Ensamblados moleculares dador-aceptor

Materiales para ONL

Dispositivos electrónicos Sistemas dador-aceptor

Sistemas fotosintéticos artificiales

p

Células solaresh

NN

D.+ A.-

Dador Puente AceptorN

N

N

N

M

e-

Ensamblados moleculares porfirina-C60

No covalente Covalente no conjugadoj g

Ph CH3

N

N

MeN

NN

NMPh

Ph

NHO

N

NN

NN

M Ph

Ph

Ph

Ph

N

PhPh

N

N

N

N

MN

CH3

PhS S

S S

R

n

Covalente conjugado

N

Ph

R

Covalente conjugado