aromatic diimides – potential dyes for use in smart films
TRANSCRIPT
Aromatic Diimides – Potential Dyes for Use in Smart Films and Fibers
New aromatic diimide fluorescent dyes have been prepared with potential for use as chemical sensors and in chromogenic polymers. These dyes have been designed to utilize excited state electron transfer reactions as the means for sensing chemical species. For example, an aniline end-capped anthryl diimides functions effectively as an “on-off’ sensor for pH and the detection of phosphoryl halide based chemical warfare agents, such as Sarin. In the absence of analytes, fluorescence from this dye is completely quenched by excited state electron transfer from the terminal amines. Reaction of these amines inhibits electron transfer and activates the fluorescence of the dye. Another substituted anthryl diimide is presented with the capability to detect pH and nitroaromatic compounds, such as TNT. Films prepared by doping small amounts (less than 0.1 weight percent) of several of these dyes in polymers such as linear low density polyethylene exhibit thermochromism. At room temperature, these films fluoresce reddish-orange. Upon heating, the fluorescence turns green. This process is reversible – cooling the films to room temperature restores the orange emission.
1
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Aromatic Diimides –
Potential Dyes for Use in Smart Films and Fibers
Advances in Colorants, Chemicals, Finishes and Fibrous Materials
Symposium Greenville, SC June 3-4, 2008
Michael A. Meador, Daniel S. Tyson, Faysal
Ilhan, Ashley Carbaugh
Polymers BranchStructures and Materials Division
NASA Glenn Research CenterCleveland, OH 44135
[email protected](216) 433-9518
2
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Polymers Branch Overview
Propulsion Materials•
High use temperature polymers and composites
•
Material concepts for fan containment
•
New polymers and composites for COPVs
Thermal Control Materials•
High conductivity polymers and composites for radiators and heat exchangers
• Durable, lightweight insulation•
Low permeability, microcrack
resistant polymers and composites
Nanostructured
Materials• Nanocomposites (clay, graphene)• Nanotube based composites• Durable, polymer cross-linked aerogels
Functional Polymers• Adaptive polymers• Fluorescent sensors• Conductive membranes
Enable:• Reduced Mass• Enhanced Performance• Improved Durability• Reduced Cost
Design
ProcessingSynthesis
Characterization
3
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450 500 550 600 650 700 750 8000.0
0.2
0.4
0.6
0.8
1.0
Emis
sion
Inte
nsity
(mV)
Wavelength (nm)
SOCl2
Φ
= 0.12Cl2
Φ
= 0.19Cl2
S Φ
= 0.20
Cl Φ
= 0.11Me Φ
= 0.00
Organic Materials for Molecular SensorsTechnology Background
Fluorescence based methods are highly sensitive for the detection of chemical and biological species and can be used for the determination of strain and/or degradation in materials.
Fluorescent dye enhanced photomicrocraph
of Alfalfa Root
Fluorescence based strain sensors –
courtesy CWRU
NASA Applications
•
Astronaut Health Management
•
Air & Water Quality Monitoring
•
Integrated Vehicle Health Management
Research and Results
Developed route to novel diimide
materials with potential use in molecular sensors, electronics and electroluminescent devices
Tyson, Ilhan
and Meador Journal of the American Chemical Society 2006, 128, 702-703
NN
O
O
Ph
Ph O
O
H2N NH2
NO Fluorescence
NN
O
O
Ph
Ph O
O
+H3N NH3+
H+
Fluorescent
+ BaseDiamine + Acid
+ Acetyl ClP
O
O
O
POCl
O
O
POCl
O
Cl
PCl
S
Cl
POF
O
Sarin
Methylphosphonic dichloride (Cl2)
Dimethylphosphinic chloride (Cl)
Dimethyl methylphosphonate (Me)
Ethyl dichlorothiophosphate (Cl2S)
“On-Off”
Fluorescent Sensor for pH and Chemical Warfare Agents
Ilhan, Tyson and Meador Chemisty of Materials 2004, 16, 2978-80
N
N
O
O
O
O
R
R
Perylene
Crystals
Perylene
Doped Polystyrene
Perylene
in Solution
Novel Perylene
Diimide
Has Potential as Strain Sensor
Red Luminesence
in Solid State Due to Exciplex
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Photoenolization
of o-Methylphenyl
KetonesCH3
Ph
O CH2
Ph
OH 3*
CH2
OH
Ph
CH2
Ph
OH
hν
iscisc
EHO Ph
E
EE
Z
E
o-MeBP
Porter, G.; Tchir, M. J. Chem. Soc. A 1971, 3772Yang, N.C; Rivas, C.J. J. Am. Chem. Soc. 1961, 83, 2213
•
Clean, high yield route to fused 6-membered rings
Regio- and stereospecific• Not applied to polymer synthesis
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Diels-Alder Trapping of Bis(o-xylylenol)s is Versatile
C H 3
C H 3
A r
O
A r
O
" "
h ν
EE
E
E
E
E
H O P h
P h O H
X
XP h O H
P h O Hn
O H
P h
H O
P h
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Chemical Yields for Bisadduct
Formation are High
Ar'
O
Ar
O
X
Y
Y
XHO Ar'
HO Ar
1 2 (X=CO2Me, Y=H)3 (X=Y=CO2Me)
hν
Ar Ar’ X Y 2 3Ph Ph MeAcry E H 25+56Ph Ph Me2Fum E E 86
4-Me 4-Me MeAcry E H 904-Me 4-Me Me2Fum E E 82
4-OMe 4-OMe MeAcry E H 754-OMe 4-OMe Me2Fum E E 86
4-OC12H25 4-OC12H25 MeAcry E H 804-OC12H25 4-OC12H25 Me2Fum E E 80
4-CN 4-CN MeAcry E H 97
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Reaction Progess
Can Be Monitored by 1H nmr
CH3
CH3
Ph
O
Ph
O
Ph OHCO2Me
MeO2CPh OH
8
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Mono-
and Bisadduct
Quantum Yield Effected by Extent of
Diketone
Conversion
% Conversion of 1
0 20 40 60 80 100
Φ
0.0
0.2
0.4
0.6
0.8
1.0
Bisadduct formationMonoaddduct formationLoss of Diketone
MeO2CCO2Me
O
Ph
Ph OHCO2Me
CO2Me
hν Ph OHCO2Me
CO2MePh OH
MeO2C
MeO2C
1
O
Ph
O
PhMeO2C
CO2Me
hν
E/Z photoenol
formation is 1:1 →
Maximum theoretical quantum yield for monoadduct
formation is 0.5
Φ
= moles of photoproductEinstein of light
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Bisadducts
are Readily Converted into Anthracenes
Ar OH
Ar OH
X
Y
Y
X
X
Y
Ar
Ar
X
Y
Ar
X
Y
Ar
X
Y
HCl/Ac2O
N2Reflux, 3h
2 3
4
DDQ/PhClN2
Reflux, 18h Ar X Y 3 4Ph E H 90 96Ph E E 100 80
4-MeOPh E H 87 814-MeOPh E E 80 80
4-FPh E H 89 724-FPh E E 68 70
10
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Versatile Route to Arenes
CH3
O
Ph
H3CO
Ph
Ph Ph
Ph Ph
NN
O
O
O
O
R R
Ph
Ph
N
N
O
O
R
O
O
R
Ph
Ph
N
N
O
O
R
O
OR
N
N
Ph
Ph
O
O
O
O
R
R
Ph
PhPh
PhN N
NN
O R R O
OO
O
OO
O
R R
N
N N
O
O
R
O
O
R
O
R O
NOR
O Ph
Ph
Ph
Ph
J. Am. Chem. Soc. 2006, 128, 702-703 Org. Lett. 2006, 8, 577-80.
11
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New Approaches to Perylene
Diimides
N
N
O
O
O
O
R
R
N
ONO
O O
R
RZ-Shaped
Linear
Ph
O
Ph
O
N
O
O
n-C8H17
6
hν N
N
O
n-C8H17
O
HO Ph
HO Ph
O
O
n-C8H175
+
hνPh
HO
Ph
OH
7
8
1. p-TsOH/Toluene, reflux, N2
2. DDQ/Chlorobenzene, reflux, N2
R= n-C8H1
N
N
O
n-C8H17
O
Ph
Ph
O
O
n-C8H17
•
Perylene
diimides are used in a wide array of materials, including electron transfer systems, liquid crystals, photovoltaics, and fluorescent sensors.
•
Conventional synthetic routes to perylene
dimides
focused on linear derivatives –
commercial availability of dianhydride.• New approach provides route to Z-shaped perylene
bisimides
12
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Absorption and Emission Spectra of Various Z-shaped Perylene
Diimides
350 400 450 500 5500.0
0.2
0.4
0.6
0.8
1.0
Nor
mal
ized
Abs
orpt
ion
Wavelength (nm)
Hexyloxy Octyl Methoxy
500 550 600 650 7000.0
0.2
0.4
0.6
0.8
1.0
Nor
mal
ized
PL
Wavelength (nm)
Hexyloxy Octyl Methoxy
N
N
X
X
O
R
O
O
R
O
Hexyloxy
R=p-C6
H13
O-Ph, X = HOctyl
R = n-C8
H17
, X=HMethoxy
R = n-C8
H17
, X=OCH3
Φf
(CH2
Cl2
)Octyl
= 0.67p- Hexyloxyphenyl
= 0.031
13
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Perylene
Diimide
Exhibits Excimer
Fluorescence in the Solid State
Perylene
Crystals
Perylene
Doped
Polystyrene
Perylene
in Solution
•
Difference in emission color due to the formation of excited state complexes (exciplexes) in which perylenes
form stacks•
Potential to use this phenomenon in the design of thermo-
and mechanochromic
polymers
14
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Preparation of N-Octyl
Benzo[e]pyrene
Diimide
Ph O
OPhhν
N
O
R
O
N
N
O
O
R
R
O
O
HOPh
HOPh
N
N
O
O
R
R
O
O
Ph
Ph
N
N
O
O
R
R
O
O
Ph
Ph
11
12
132
R = n-C8H17 p-TsOH/TolueneReflux
16h
S8/Ph2O
Reflux, 4h
81%
96%52%
15
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Absorption and Emission of Phenanthrene
and Benzo[e]pyrene
Bisimides
and Benzo[e]pyrene
300 400 500 6000
5000
10000
15000
20000
25000
Wavelength (nm)
Extin
ctio
n C
oeffi
cien
t (M
-1cm
-1)
0.0
0.2
0.4
0.6
0.8
1.0
Norm
alized PL
N
N
O
O
n-C8H17
n-C8H17
O
O
N
N
O
O
n-C8H17
n-C8H17
O
O
1
2
3
23
1
Φ = 0.24
Φ = 0.037
Φ = 0.054
Spectra and quantum yields measured in CH2
Cl2
16
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Synthesis of Anthracene Diimides
CH3
OO
H3C
X
X
N
O
O
R
NN
O
OO
O
R R
NN
O
OO
O
R RNN
O
OO
O
R R
HO
OH
X
X
X
X
X
X
hν
p-TsOH/ TolueneReflux, N2
Sulfur/ Ph2O
Reflux, N2
88-97%
77-98%26-71%
X = H, OCH3, CNR = n-C8H17, Ph, 4-MeOPh, 4- (C6H13O)Ph, 4-NO2Ph
17
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Synthesis of Tetraaryl
Diimides –
Trapping Unaffected by Steric
Hindrance
O
O
X
Y
X
Y
hν (Pyrex)
N
O
O
R
NN
O
R
O
OH O
R
OOH
X
X
Y
NN
O
R
O
O
R
O
X
X
Y
Y
NN
O
R
O
O
R
O
X
X
Y
Y
71-88%Y
p-TsOH/ TolueneReflux
76-96%63-71%
X = H, OCH3,Y = H, OCH3, CNR = n-C8H17, p-(C6H13O)Ph
Benzene, N2
Sulfur/ Ph2O
Reflux/N218h
18
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Substituent
and Solvent Effects on Photophysics
of Anthryl
Diimides
NNR
O
O
O
R
O
X
X
Effect of Solvent on Fluorescence Quantum Yields
R = Octyl R = Aryl R=Aryl, X=OMe R= Aryl, X=CN
Φf
0.0
0.1
0.2
0.3
0.4
Toluene THF Acetone
450 500 550 600 650 700 7500.0
0.2
0.4
0.6
0.8
1.0
1.2
Nor
. PL
(mV)
Wavelength (nm)
Tol CHCl3 EA THF DCE ACE
425 450 475 500 525 5500.0
0.2
0.4
0.6
0.8
1.0
1.2
Nor
. PL
(mV)
Wavelength (nm)
tol Cl3 EA THF DCE ACE ACN
R = Octyl
OC6H13R =
19
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Substituent
and Solvent Effects on the Photophysics
of Diimides
NNR
O
O
O
R
O
X
X
Y
Y
Fluorescence Quantum Yields
R = Octyl R = Aryl X,Y= OMe X= OMe, Y=CN
Φf
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
Toluene THF Acetone
450 500 550 600 650 700 7500.0
0.2
0.4
0.6
0.8
1.0
1.2
Nor
. PL
(mV)
Wavelength (nm)
Tol Cl3 EA THF DCE Ace ACN
500 600 7000.0
0.4
0.8
Nor
. PL
(mV)
Wavelength (nm)
Tol Cl3 EA THF DCE Ace ACN
X, Y = H
X, Y = OMe
20
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Twisting of N-Aryl Group Inhibits Charge Transfer
NNR
O
O
O
R
O
21
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Low Temperature Emission Spectra
450 500 550 6000.0
0.2
0.4
0.6
0.8
1.0
Nor
. PL
(mV)
Wavelength (nm)
DM DP DPO DC
Spectra measured in MeTHF
at 77°K
Reducing temperature:•
Reduces rotational motion
•
Inhibits charge transfer
22
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NN
O
O
R R
O
O
X
X
Steric
and Electronic Effects Regulate Excited State Photophysics
SWLW
e-
Donor R’sPolar Solvents
e-
Acceptor R’sRestricted Rotation
Only SW observed• N-octyl
diimides•
Sterically
crowded N-aryl R’s
• Low temperatures
e-
Donor X’s
e-
Acceptor X’s
Only LW ObservedElectron donating N-aryls
+Electron withdrawing X
+Polar solvents
Dual emissionElectron donating N-aryls
+Electron donating X
OrElectron donating N-aryl
+ Non-polar solvents
23
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Anthracene Diimide
Provides Platform for Charge Transfer Mediated Fluorescent Sensors
NN
O
O
O
O
RR
X
XElectron donors that are tailored to interact with given analyte
Tune absorption and emission
24
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New Anthracene Diimide
Molecular Sensor
• Charge Transfer from NH2
quenches fluorescence•
Protonation
or acetylation
of the NH2 prevents charge transfer, activates fluorescence
• Potential use as:sensor for pH, chemical agents (nerve gas)polymer cure monitoring
Ilhan, Tyson and Meador Chem. Mater. 2004
NN
O
O
Ph
Ph O
O
H2N NH2
NO Fluorescence
NN
O
O
Ph
Ph O
O
+H3N NH3+
H+
Fluorescent
25
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PO
O
O
POCl
O
O
POCl
O
Cl
PCl
S
Cl
POF
O
Sarin
Methylphosphonic dichloride (Cl2)
Dimethylphosphinic chloride (Cl)
Dimethyl methylphosphonate (Me)
Ethyl dichlorothiophosphate (Cl2S)
Diimide
Can Detect Organophosphates
450 500 550 600 650 700 750 8000.0
0.2
0.4
0.6
0.8
1.0
Emis
sion
Inte
nsity
(mV)
Wavelength (nm)
SOCl2
Φ
= 0.12
Cl2
Φ
= 0.19
Cl2
S Φ
= 0.20
Cl Φ
= 0.11
Me Φ
= 0.00
26
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Sensor Effective for Both Liquids and Vapors
27
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Anthracene Diimide
Provides Platform for Charge Transfer Mediated Fluorescent Sensors
NN
O
O
O
O
RR
X
XElectron donors that are tailored to interact with given analyte
Tune absorption and emission
28
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Anthracene Dianhydride
is Key to Tailoring Sensor Specificity
CH3
H3CO
OCO2MeMeO2C
CO2Me
CO2MeMeO2C
MeO2CPh OH
Ph OH
Ph
Ph
MeO2C
MeO2C
CO2Me
CO2Me
hν (Pyrex)
10 eq.C6H6, N2
33%
HCl/Ac2OReflux, 18h
N2
92%
Ph
Ph
HO2C
HO2C
CO2H
CO2H
NaOH/H2O + EtOH
Reflux, 18hN2
93%
Ph
Ph
OO
O
O
O
O
Ac2OReflux, 18h
N2
94%
Enables attachment of substituents to imide N that might be photosensitive, e.g., pyridyl groups
29
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Absorption and Emission Spectra
NN
O
O
O
O
NN
400 500 600 7000.0
0.2
0.4
0.6
0.8
1.0
Wavelength (nm)
Nor
mal
ized
Abs
.
0.0
0.2
0.4
0.6
0.8
1.0
Norm
alized PL
Absorption and Emission Spectra in Toluene and 1,2-Dichloroethane
Φf
= 0.035 in Tolueneτf
= 90ps
30
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Diimide
Fluoresence
Shows Solvatochromic Behavior
Effect of Solvent Polarity on Emission Spectra
Wavelength, nm
450 500 550 600 650 700 750 800
Rel
. Int
ensi
ty
0.0
0.2
0.4
0.6
0.8
1.0
1.2
TolueneChloroformTHFEtCl2
400 nm excitation
31
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Stern Volmer Quenching with 2,4-DNT
[Q], M
0.00 0.01 0.02 0.03 0.04 0.05 0.06
I 0/I
0.8
1.0
1.2
1.4
1.6
1.8
Diimide
Fluorescence Quenched by Nitroaromatics
Excited state charge transfer from dye to nitroaromatics
quenches fluorescence
500 550 600 650 700 750 8000
200000
400000
600000
800000
1000000
1200000
1400000
1600000
1800000
PL (m
A)
Wavelength (nm)
0.000 M 0.010 M 0.020 M 0.030 M 0.040 M 0.050 M 0.060 M
32
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Fluorescence Inhibited by Addition of Acids
450 500 550 600 650 700 750 8000
200000
400000
600000
800000
1000000
1200000
1400000
1600000
1800000
PL (c
ps)
Wavelength (nm)
0 1 2 4 8
Addition of TFA protonates
amine and inhibits charge transfer
Excitation at 400 nm
33
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Aggregate Formation in Solid State is Evident in X-Ray
34
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Increased Loading Levels Lead to Red Shifted Emission
Emission Spectra in Polystyrene
Wavelength, nm
400 450 500 550 600 650 700 750 800
Rel
. Int
ensi
ty
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0.1 weight %0.5 weifght %
Suggests formation of dye aggregates in the polymer
35
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TPAA Doped Films Exhibit Thermochromic Behavior
Effect of Temperature on Emission Spectra of Dye Doped LLDPE
Wavelength, nm
400 450 500 550 600 650 700 750 800
Rel
. Int
ensi
ty
0.0
0.2
0.4
0.6
0.8
1.0
1.2
25oC51oC87oC121oC153oC
• Aggregation disrupted at higher temperatures –
blue shift• Process is reversible
36
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Mechanochromic
and Themochromic
Polymers
Crenshaw, B.R. and Weder, C. Macromolecules 2003, 15, 4717-24
H3CO
CN
OCH3
OCH3
CN
OCH3
H3CO
CNCN
OCH3
O
CN
OCH3
OCH3
CN
O
BCMDBBCMB
BCEDB
Stretched Films of 0.18 wt. % BCMDB and BCMB in LLPE
PL Spectra of 0.2 wt. % BCDMB/LLPE Film as a Function of Temperature
37
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Polymer Films and Nanowires
for Field Effect Transistors
106
104
102
100
10-2
10-4
10-6
10-8
10-10
10-12
10-14
10-16
Ag, Cu Fe Mg
In, Sn
Ge
Si
AgBr
Glass
Diamond
Nylon
Quartz
INSU
LATO
RS
SEM
ICO
ND
UC
TOR
S M
ETA
LS
INC
REA
SIN
G D
OPI
NG
LEV
ELS
S/cm
Doped trans-(CH)x[105 S/cm]
Doped polyaniline [103 S/cm]
trans-(CH)x[10-5 S/cm]
Polyaniline[10-10 S/cm]
VS-D (volts)
-1.0-0.8-0.6-0.4-0.20.0
I S-D (n
A)
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
VG
- 20 V
0 V
+ 10 V
+ 20 V
+ 30 V
VS-D (volts)-5-4-3-2-10
I S-D
(nA
)
-20
-15
-10
-5
0
Au SiO2
Au
Nanofiber
5 mμ
Applications:•Small size, power-efficient flexible electronic circuitry for space exploration applications•Communications and data storage circuitry that can be interwoven
into clothing and other surfaces
•Active matrix light emitting diodes, RF identification cards
Technology development requiresinterdisciplinary collaboration
Nano-metrology
DeviceCharacterization
MaterialsOptimization
AFM image of polyaniline/polyethylene nanofiber
Current-
voltage characteristics of nanofiber FET
SEM image of nanofiber Deposited on metallized
SiO2
/Si substrate
Point of Contact:Dr. Félix A. Miranda, RCA216-433-6589
The electrical conductivity ofbulk polyaniline can be variedFrom 10-10
to 6x103
siemens per centimeter
Antenna, Microwave and Optical Systems Branch (RCA); Polymers Branch (RMP)
38
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Electrospun Pentacene/PEO Fiber (vacuum)20 August 2007
VDS (V)
-60 -50 -40 -30 -20 -10 0
I (pA
)
-80
-60
-40
-20
0
20
0V-10V-20V-30V-40V
Pentacene/PEO nanofibers
grown by Prof. Nicholas Pinto, U of Puerto Rico-
Humacao
Pentacene/PEO Nanofiber
FETs
39
National Aeronautics and Space Administration
www.nasa.gov
Twistacenes Wudl, F. et al Org. Lett. 2003, 5, 4433-36
•
Addition of pendant phenyls adds steric
bulk-enhances photooxidative
stability, prevents quenching
•
Addition of perylene
endgroups
enhances Φf
40
National Aeronautics and Space Administration
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Twistacenes
Effect of added TBH on intensity of PL and EL of poly(fluorene
films)
C8H17C8H17
Xu, Q.; Duong, H.M.; Wudl, F.; Yang, Y. Appl. Phys. Lett. 2004, 85, 3357-59
41
National Aeronautics and Space Administration
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Beyond Anthracenes
and Perylenes
•
Increasing number of benzene rings (conjugation) makes the molecule more polarizable
•
Adding pendant groups improves stability and solid state fluorescence efficiency
•
Flexible chemistry enables tailoring of electronic properties
•
Potential for use in photovolatics, molecular electronics and photonics
CH3
O
Ph
H3CO
Ph
Ph Ph
Ph Ph
NN
O
O
O
O
R R
Ph
Ph
N
N
O
O
R
O
O
R
Ph
Ph
N
N
O
O
R
O
OR
N
N
Ph
Ph
O
O
O
O
R
R
Ph
PhPh
PhN N
NN
O R R O
OO
O
OO
O
R R
N
N N
O
O
R
O
O
R
O
R O
NOR
O Ph
Ph
Ph
Ph
42
National Aeronautics and Space Administration
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Summary
•
Developed new route to highly substituted aryl diimides–
Anthracenes–
Perylenes–
Pyrenes–
Higher homologues•
Exploited excited state behavior to develop fluorescent sensors–
Chemical species–
Warfare agents–
Temperature•
Incorporation of these dyes into polymers has the potential for making “smart”
films, fibers, and
composites
43
National Aeronautics and Space Administration
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Acknowledgements
•
NASA Undergraduate Student Research Program•
NASA Grant NNC07BA13B
•
Funding from the Fundamental Aeronautics Program and the Glenn Innovative Research and Development Fund