1. Synthesis of dicyano and diTMS-Acetylide NDIs and their applications
David Allen
Denison University, Department of Chemistry and Biochemistry, Granville, OH 43023
Dr. Joseph Reczek
Methods
Discussion
Acknowledgements
This research was supported by funds from the Anderson Endowment of Denison University. I’d
like to personally thank Dr. Joseph Reczek for support and guidance, Lovely Abocado for
experimental help, Mr. Philip Waite, The Reczek Group, The Fantini Lab, The Department of
Chemistry and Biochemistry at Denison University, Haley Grimm and Riley Sechrist for hands-
on assistance, and my family.
Literature Cited
Grimm, H. Synthesis of Core-Substituted Naphthalene Diimide Derivatives as Electron Poor Donor-Acceptor
Columnar Liquid Crystal Components. Senior Thesis.
Thompson, A., Grimm, H., Gray Bé, A., McKnight, K., and Reczek, J. Efficient bromination of naphthalene
dianhydride and microwave assisted synthesis of core-brominated naphthalene diimides Synthesis.
Commun. 2015, 45, 1127-1136.
Vahedra, G., Maloney, R., Garcia-Garibay, M., and Dunn, B. Naphthalene Diimide Based Materials
with Adjustable Redox Potentials: Evaluation for Organic Lithium-Ion Batteries. Chemistry of Materials.
2014, 26 (24), 7151-7157.
Introduction
A
A
0.57
0.77
0.97
1.17
1.37
1.57
250 350 450 550 650 750 850
Absorbance
Wavelength (nm)
0.1
0.3
0.5
0.7
0.9
1.1
1.3
1.5
250 450 650 850 1050 1250 1450
Absorbance
Wavelength (nm)
Electron poor Electron rich
Energy
Ea
Eb
Ec < Ea and Eb
The Reczek group works with facilitating sustainable energy alternatives involving solar
energy. Our group achieves this by synthesizing Donor Acceptor Columnar Liquid
Crystals, which involve the self-assembly of electron poor and electron rich aromatics
(Figure One) which subsequently contains a new, smaller HOMO-LUMO gap, allowing
for a higher wavelength of light to be absorbed(Figure Two).
To obtain the brominated NDI intermediate, we added Sulfuric Acid and Bromine and allowed it to
reflux at 100℃ for 48 hrs. Then we take the resulting compound and add octylamine, acetic acid and
heatitinamicrowave at115℃for35m.
Our first substituent is a dicyano NDI (dcNDI). To synthesize this compound we added excess Copper
(I)CyanideandanaproticsolventsuchasDMFandrefluxat100℃fortwohours(FigureFour).
Our second substituent is a di-TMS NDI (dtNDI). Tosynthesize this compound we added excess TEA,
PdCl2(PPh3)2,and Ethyntrimethylsilane and stirred under Nitrogen gas for two hours at 0º C and then at
roomtemperatureovernight(FigureFour).
HOMO: -4.31 eV
Figure Six. 1H NMR spectroscopy of Di-Cyano Naphthalene Di-Imide.
Figure One. Self-assembly of Electron rich and Electron poor aromatics, enhancing pi-pi interaction.
Results
.
a. b.
Figure Seven. a. Chemical structures of dcNDI (dcNDI) and diAmino Napthalene (dAm). b.
Images of dcNDI and dAm along with the image of the mixture’s color (after mixing and
adding heat). c. UVVis and NIR absorbance measurement of the mixture ( blue arrow
represents charge-transfer band). d. Crystallography image of mixture.
Results
.
Synthesis
The Reczek Group has long had trouble utilizing a consistent and reliable protocol for the
synthesis of di-cyano NDI. Now, with a much more simplified procedure, we have been able to
successfully implement a protocol that has high yields of dcNDI.
Absorbance
Within my experimentation we found charge-transfer absorbance with these specific DACLC’s.
In fact, the extension of absorbance of the dcNDI:dAm mixture into the NIR range is the largest
that the Reczek lab has seen so far. This finding is consistent with current research as the dc:dAm
mixture has the smallest HOMO-LUMO gap, meaning that it’s extension into the NIR range
corresponds. The colors that comes after heating the mixtures are representative of the new
wavelengths of light being absorbed which agrees with the new HOMO LUMO gap. While the
specific interest of the dcNDI component is it’s very low HOMO level, the interest in regards to
the dtNDI component is whether non-covalent interactions (of the core substituents) influence the
absorbance profile. Our investigations support further research into this topic as the dtNDI:dAm
mixture has a similar absorbance profile to the dc:dAl mixture, even though they contain different
HOMO-LUMO gaps.
Crystals
While the investigation into the shapes and formation of the crystals is still early, of particular
interest within DACLCs is the linearity of the polarized light, of which all four mixtures form at
at least one phase-transition.
Figure Nine. 1H NMR spectroscopy of Di-TMS Naphthalene Di-Imide
b.
a.
c.0.95
1.15
1.35
1.55
1.75
1.95
2.15
2.35
275 375 475 575 675 775 875
Absorbance
Wavelength (nm)
HOMO: -3.33 eV
Figure Eight. a. Chemical structures of dcNDI and diAlkoxy Napthalene (dAl). b. Images of
dcNDI and dAl along with the image of the mixtures color (after mixing and adding heat). c.
UVVis and NIR absorbance measurement of the mixture ( blue arrow represents charge-
transfer band). d. Crystallography image of mixture.
d.c.
b.
c.
a.
d.
86.2℃
190℃
Figure Two. Energy diagram illustrating the charge-transfer (new HOMO-LUMO gap) absorbance of the DACLC.
Figure Three. Synthesis Procedure of di-brominated NDI1.
Figure Four. a. Synthesis Procedure of di-cyano NDI2. b. Electrostatic potential map of dcNDI.
a.
b.
Figure Five. a. Synthesis Procedure of dtNDI2. b. Electrostatic potential map of dtNDI.
a. b.
A
A
b.
d. 76.2℃
0.5
1
1.5
2
2.5
3
3.5
275 475 675 875
Absorbance
Wavelength (nm)
d. 76.2℃
a.
Figure Ten. a. Chemical structures of dtNDI and dAm. b. Images of dtNDI and dAm along
with the image of the mixtures color (after mixing and adding heat). c. UVVis and NIR
absorbance measurement of the mixture ( blue arrow represents charge-transfer band). d.
Crystallography image of mixture.
c.
Figure 11. a. Chemical structures of dtNDI and dAl. b. Images of dcNDI and dAl along with
the image of the mixtures color (after mixing and adding heat). c. UVVis and NIR absorbance
measurement of the mixture ( blue arrow represents charge-transfer band). d. Crystallography
image of mixture.
87℃ 209 ℃
105.5℃ 177.2℃
A B
Figure 12. a. Image of the dcNDI:dAm mixture at 87℃. b. Image of the dcNDI:dAl mixture at
209℃. c. a. Image of the dtNDI:dAm mixture at 105.5℃. d. a. Image of the dtNDI:dAm mixture
at 177.2℃.
a. b.
c. d.