Harnessing Direct
(Hetero)Arylation in Pursuit of
a Saddle-Shaped Perylene Diimide Tetramer
Josh D.
B. Koenig
Audrey Laventure
Gregory C. Welch
10.1021/acsaem.9b01978.s001
https://acs.figshare.com/articles/journal_contribution/Harnessing_Direct_Hetero_Arylation_in_Pursuit_of_a_Saddle-Shaped_Perylene_Diimide_Tetramer/10354265
This contribution explores the direct (hetero)arylation
(DHA) cross-coupling
of a saddle-like, π-conjugated cyclooctatetrathiophene (<b>Th</b><sub><b>4</b></sub>) core with the N-annulated perylene
diimide (PDI) chromophore. Replacing the bulky pivalic acid with acetic
acid enabled a facile cross-coupling, selectively forming a PDI tetramer
(<b>Th</b><sub><b>4</b></sub><b>PDI</b><sub><b>4</b></sub>) in a 70% overall yield. The optoelectronic properties
of <b>Th</b><sub><b>4</b></sub><b>PDI</b><sub><b>4</b></sub> were characterized and density functional theory (DFT)
was used to calculate the optimized molecular geometry and molecular
orbitals (MOs). Energy levels of MOs determined by cyclic voltammetry
corresponded well with those
calculated using DFT. The molecular geometry calculated by DFT showed <b>Th</b><sub><b>4</b></sub><b>PDI</b><sub><b>4</b></sub> adopts two separate PDI–PDI conformations (propeller
and double-decker). Organic photovoltaic (OPV) devices were fabricated
using a blend of PTB7-Th/<b>Th</b><sub><b>4</b></sub><b>PDI</b><sub><b>4</b></sub>, where an initial power conversion
efficiency (PCE) of 1.89% was improved by testing a series of solvent
additives and thermal annealing techniques. Through use of 3% (v/v)
1-chloronaphthalene additive, a combination of higher short circuit
current (<i>J</i><sub>sc</sub> = 10.2 mA/cm<sup>2</sup>)
and fill factor (FF = 42%) led to an overall increase in PCE to 4.26%.
2019-11-19 17:04:01
MO
Saddle-Shaped Perylene Diimide Tetramer
PTB 7-Th Th 4 PDI 4
Energy levels
acetic acid
optoelectronic properties
PDI tetramer
annealing techniques
power conversion efficiency
PCE
pivalic acid
OPV
cyclic voltammetry
Organic photovoltaic
FF
DFT
Th 4 PDI 4
J sc
DHA
Th 4
N-annulated perylene diimide