Enforcing Extended Porphyrin J-Aggregate Stacking in Covalent Organic Frameworks.

Journal article

Publication Details

Author(s): Keller N, Calik M, Sharapa D, Soni H, Zehetmaier PM, Rager S, Auras F, Jakowetz AC, Görling A, Clark T, Bein T
Journal: Journal of the American Chemical Society
Publication year: 2018
Volume: 140
Pages range: 16544
ISSN: 0002-7863


The potential of covalent organic frameworks (COFs) for realizing porous, crystalline networks with tailored combinations of functional building blocks has attracted considerable scientific interest in the fields of gas storage, photocatalysis, and optoelectronics. Porphyrins are widely studied in biology and chemistry and constitute promising building blocks in the field of electroactive materials, but they reveal challenges regarding crystalline packing when introduced into COF structures due to their nonplanar configuration and strong electrostatic interactions between the heterocyclic porphyrin centers. A series of porphyrin-containing imine-linked COFs with linear bridges derived from terephthalaldehyde, 2,5-dimethoxybenzene-1,4-dicarboxaldehyde, 4,4'-biphenyldicarboxaldehyde and thieno[3,2- b]thiophene-2,5-dicarboxaldehyde, were synthesized, and their structural and optical properties were examined. By combining X-ray diffraction analysis with density-functional theory (DFT) calculations on multiple length scales, we were able to elucidate the crystal structure of the newly synthesized porphyrin-based COF containing thieno[3,2- b]thiophene-2,5-dicarboxaldehyde as linear bridge. Upon COF crystallization, the porphyrin nodes lose their 4-fold rotational symmetry, leading to the formation of extended slipped J-aggregate stacks. Steady-state and time-resolved optical spectroscopy techniques confirm the realization of the first porphyrin J-aggregates on a > 50 nm length scale with strongly red-shifted Q-bands and increased absorption strength. Using the COF as a structural template, we were thus able to force the porphyrins into a covalently embedded J-aggregate arrangement. This approach could be transferred to other chromophores; hence, these COFs are promising model systems for applications in photocatalysis and solar light harvesting, as well as for potential applications in medicine and biology.

FAU Authors / FAU Editors

Clark, Timothy apl. Prof. Dr.
Görling, Andreas Prof. Dr.
Lehrstuhl für Theoretische Chemie
Sharapa, Dmitry
Soni, Himadriben
Lehrstuhl für Theoretische Chemie

External institutions with authors

Ludwig-Maximilians-Universität (LMU)
University of Cambridge

How to cite

Keller, N., Calik, M., Sharapa, D., Soni, H., Zehetmaier, P.M., Rager, S.,... Bein, T. (2018). Enforcing Extended Porphyrin J-Aggregate Stacking in Covalent Organic Frameworks. Journal of the American Chemical Society, 140, 16544. https://dx.doi.org/10.1021/jacs.8b08088

Keller, Niklas, et al. "Enforcing Extended Porphyrin J-Aggregate Stacking in Covalent Organic Frameworks." Journal of the American Chemical Society 140 (2018): 16544.


Last updated on 2019-21-07 at 07:57