1 research outputs found
Theory-Driven Insight into the Crystal Packing of Trialkylsilylethynyl Pentacenes
The
functionalization of oligoacenes and similar π-conjugated
chromophores with trialkylsilylethynyl groups has proven to
be a versatile means to enhance solubility and solution processability
and engineer solid-state packing arrangements to produce organic semiconductors
that demonstrate outstanding charge-carrier transport characteristics.
While a general, empirical-based geometric model has been developed
and implemented to direct the solid-state packing arrangements of
these molecular materials, there exist numerous examples where the
model falters. Here, we employ electronic structure methods to probe
the noncovalent, intermolecular interactions of two closely related
systems that result in two very different crystal packing configurations:
triisopropylsilylethynyl (TIPS) pentacene and its triethylsilylethynyl
(TES) analog. The quantum-chemical evaluation details how the slightly
larger electron density contained within the volume of the TIPS moiety
with respect to TES is in part responsible for the solid-state packing
variations. We also make use of periodic density functional theory
(DFT) methods to develop in silico polymorphs of these systems and
explore the electronic characteristics of varied packing arrangements.
The results suggest that TES pentacene, if processed correctly, could
be developed into a material with improved charge-carrier transport
characteristics when compared to its native form. Overall, the theory-driven
insight developed in this work lays an important foundation to build
a more robust crystal engineering paradigm for these technologically
relevant organic semiconductors