Modelling dynamic effects to determine transport properties in semiconducting MOFs containing 1D pentacene stacks

Activity: Talk or presentationPoster presentationScience to science

Description

Metal-Organic Frameworks (MOFs) can be used to extrinsically control the orientation
of molecules with respect to each other. In this way, π-conjugated units can be
positioned to create materials with favorable electronic properties, allowing the design
of MOFs as organic semiconductors.
This approach was, for example, used to create a MOF incorporating one-dimensional
stacks of pentacene units [1]. The electron transport in this material, however, was
found to be hindered by dynamical disorder effects. Additionally, it was shown that the
specific stacking in the original MOFs resulted in a particularly weak electronic coupling
between neighboring pentacenes [2]. The latter could be overcome by structural
modifications to precisely control the stacking distance and, thus, the relative
arrangement of neighboring pentacenes. Models of these materials were found to
display massively improved charge transport properties in the static picture.
In this contribution, we present newly found polymorphs, containing unconventional,
non-orthorhombic networks. Furthermore, we use density functional theory and highly
accurate machine-learned force fields [3] to model dynamic effects in these new
polymorphs, as well as in the previously reported enhanced semiconducting MOFs.
This dynamical picture is then used to get more sophisticated predictions for the
electronic transport properties and to suggest additional structural modifications of
these MOFs to further boost their transport properties.

[1] Haldar, R. et al., Interplay of Structural Dynamics and Electronic Effects in an
Engineered Assembly of Pentacene in a Metal-Organic Framework. Chem. Sci., 2021,
12 (12), 4477-4483.
[2] Zojer, E.; Winkler, C., Maximizing the Carrier Mobilities of Metal-Organic
Frameworks Comprising Stacked Pentacene Units. J. Phys. Chem. Lett., 2021, 12
(29), 7002-7009.
[3] Jinnouchi, R. et al., On-the-Fly Active Learning of Interatomic Potentials for Large-
Scale Atomistic Simulations. J. Phys. Chem. Lett., 2020, 11, 6946-6955.
Period4 Sep 20227 Sep 2022
Event title8th International Conference on Metal-Organic Frameworks and Open Framework Compounds: MOF 2022
Event typeConference
LocationDresden, Germany, SaxonyShow on map
Degree of RecognitionInternational

Keywords

  • MOF
  • Metal-Organic Framework
  • Pentacene
  • Electronic Transport
  • Simulation

Fields of Expertise

  • Advanced Materials Science