Phenylene ethynylene-tethered perylene bisimide folda-dimer and folda-trimer

Investigations on folding features in ground and excited states

Benjamin Fimmel, Minjung Son, Young Mo Sung, Matthias Grüne, Bernd Engels, Dongho Kim, Frank Würthner

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

In this work, we have elucidated in detail the folding properties of two perylene bisimide (PBI) foldamers composed of two and three PBI units, respectively, attached to a phenylene ethynylene backbone. The folding behaviors of these new PBI folda-dimer and trimer have been studied by solvent-dependent UV/Vis absorption and 1D and 2D NMR spectroscopy, revealing facile folding of both systems in tetrahydrofuran (THF). In CHCl3 the dimer exists in extended (unfolded) conformation, whereas partially folded conformations are observed in the trimer. Temperature-dependent1H NMR spectroscopic studies in [D8 ]THF revealed intramolecular dynamic processes for both PBI foldamers due to, on the one hand, hindered rotation around C-N imide bonds, on the other hand, backbone flapping; the latter process being energetically more demanding as it was observed only at elevated temperature. The structural features of folded conformations of the dimer and trimer have been elucidated by different 2D-NMR spectroscopy (e.g., ROESY and DOSY) in [D8]THF. The energetics of folding processes for the PBI dimer and trimer have been assessed by calculations applying various methods, particularly the semiempirical PM6-DH2 and the more sophisticated B97D approach, in which relevant dispersion corrections are included. These calculations corroborate the results of NMR spectroscopic studies. Folding features in the excited states of these PBI foldamers have been characterized by using time-resolved fluorescence and transient absorption spectroscopy in THF and CHCl3, exhibiting similar solvent-dependent behavior as observed for the ground state. Interestingly, photoinduced electron transfer (PET) process from electron-donating backbone to electron-deficient PBI core for extended, but not for folded, conformations was observed, which can be explained by a fast relaxation of excited PBI stacks in the folded conformation into fluorescent excimer states.

Original languageEnglish
Pages (from-to)615-630
Number of pages16
JournalChemistry - A European Journal
Volume21
Issue number2
DOIs
Publication statusPublished - 2015 Jan 7

Fingerprint

Excited states
Dimers
Ground state
Conformations
Nuclear magnetic resonance spectroscopy
Electrons
Nuclear magnetic resonance
Absorption spectroscopy
Imides
Fluorescence
perylene bisimide
Temperature
tetrahydrofuran

All Science Journal Classification (ASJC) codes

  • Chemistry(all)

Cite this

Fimmel, Benjamin ; Son, Minjung ; Sung, Young Mo ; Grüne, Matthias ; Engels, Bernd ; Kim, Dongho ; Würthner, Frank. / Phenylene ethynylene-tethered perylene bisimide folda-dimer and folda-trimer : Investigations on folding features in ground and excited states. In: Chemistry - A European Journal. 2015 ; Vol. 21, No. 2. pp. 615-630.
@article{c41571951aea4a53b86935e2a2b277df,
title = "Phenylene ethynylene-tethered perylene bisimide folda-dimer and folda-trimer: Investigations on folding features in ground and excited states",
abstract = "In this work, we have elucidated in detail the folding properties of two perylene bisimide (PBI) foldamers composed of two and three PBI units, respectively, attached to a phenylene ethynylene backbone. The folding behaviors of these new PBI folda-dimer and trimer have been studied by solvent-dependent UV/Vis absorption and 1D and 2D NMR spectroscopy, revealing facile folding of both systems in tetrahydrofuran (THF). In CHCl3 the dimer exists in extended (unfolded) conformation, whereas partially folded conformations are observed in the trimer. Temperature-dependent1H NMR spectroscopic studies in [D8 ]THF revealed intramolecular dynamic processes for both PBI foldamers due to, on the one hand, hindered rotation around C-N imide bonds, on the other hand, backbone flapping; the latter process being energetically more demanding as it was observed only at elevated temperature. The structural features of folded conformations of the dimer and trimer have been elucidated by different 2D-NMR spectroscopy (e.g., ROESY and DOSY) in [D8]THF. The energetics of folding processes for the PBI dimer and trimer have been assessed by calculations applying various methods, particularly the semiempirical PM6-DH2 and the more sophisticated B97D approach, in which relevant dispersion corrections are included. These calculations corroborate the results of NMR spectroscopic studies. Folding features in the excited states of these PBI foldamers have been characterized by using time-resolved fluorescence and transient absorption spectroscopy in THF and CHCl3, exhibiting similar solvent-dependent behavior as observed for the ground state. Interestingly, photoinduced electron transfer (PET) process from electron-donating backbone to electron-deficient PBI core for extended, but not for folded, conformations was observed, which can be explained by a fast relaxation of excited PBI stacks in the folded conformation into fluorescent excimer states.",
author = "Benjamin Fimmel and Minjung Son and Sung, {Young Mo} and Matthias Gr{\"u}ne and Bernd Engels and Dongho Kim and Frank W{\"u}rthner",
year = "2015",
month = "1",
day = "7",
doi = "10.1002/chem.201405231",
language = "English",
volume = "21",
pages = "615--630",
journal = "Chemistry - A European Journal",
issn = "0947-6539",
publisher = "Wiley-VCH Verlag",
number = "2",

}

Phenylene ethynylene-tethered perylene bisimide folda-dimer and folda-trimer : Investigations on folding features in ground and excited states. / Fimmel, Benjamin; Son, Minjung; Sung, Young Mo; Grüne, Matthias; Engels, Bernd; Kim, Dongho; Würthner, Frank.

In: Chemistry - A European Journal, Vol. 21, No. 2, 07.01.2015, p. 615-630.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Phenylene ethynylene-tethered perylene bisimide folda-dimer and folda-trimer

T2 - Investigations on folding features in ground and excited states

AU - Fimmel, Benjamin

AU - Son, Minjung

AU - Sung, Young Mo

AU - Grüne, Matthias

AU - Engels, Bernd

AU - Kim, Dongho

AU - Würthner, Frank

PY - 2015/1/7

Y1 - 2015/1/7

N2 - In this work, we have elucidated in detail the folding properties of two perylene bisimide (PBI) foldamers composed of two and three PBI units, respectively, attached to a phenylene ethynylene backbone. The folding behaviors of these new PBI folda-dimer and trimer have been studied by solvent-dependent UV/Vis absorption and 1D and 2D NMR spectroscopy, revealing facile folding of both systems in tetrahydrofuran (THF). In CHCl3 the dimer exists in extended (unfolded) conformation, whereas partially folded conformations are observed in the trimer. Temperature-dependent1H NMR spectroscopic studies in [D8 ]THF revealed intramolecular dynamic processes for both PBI foldamers due to, on the one hand, hindered rotation around C-N imide bonds, on the other hand, backbone flapping; the latter process being energetically more demanding as it was observed only at elevated temperature. The structural features of folded conformations of the dimer and trimer have been elucidated by different 2D-NMR spectroscopy (e.g., ROESY and DOSY) in [D8]THF. The energetics of folding processes for the PBI dimer and trimer have been assessed by calculations applying various methods, particularly the semiempirical PM6-DH2 and the more sophisticated B97D approach, in which relevant dispersion corrections are included. These calculations corroborate the results of NMR spectroscopic studies. Folding features in the excited states of these PBI foldamers have been characterized by using time-resolved fluorescence and transient absorption spectroscopy in THF and CHCl3, exhibiting similar solvent-dependent behavior as observed for the ground state. Interestingly, photoinduced electron transfer (PET) process from electron-donating backbone to electron-deficient PBI core for extended, but not for folded, conformations was observed, which can be explained by a fast relaxation of excited PBI stacks in the folded conformation into fluorescent excimer states.

AB - In this work, we have elucidated in detail the folding properties of two perylene bisimide (PBI) foldamers composed of two and three PBI units, respectively, attached to a phenylene ethynylene backbone. The folding behaviors of these new PBI folda-dimer and trimer have been studied by solvent-dependent UV/Vis absorption and 1D and 2D NMR spectroscopy, revealing facile folding of both systems in tetrahydrofuran (THF). In CHCl3 the dimer exists in extended (unfolded) conformation, whereas partially folded conformations are observed in the trimer. Temperature-dependent1H NMR spectroscopic studies in [D8 ]THF revealed intramolecular dynamic processes for both PBI foldamers due to, on the one hand, hindered rotation around C-N imide bonds, on the other hand, backbone flapping; the latter process being energetically more demanding as it was observed only at elevated temperature. The structural features of folded conformations of the dimer and trimer have been elucidated by different 2D-NMR spectroscopy (e.g., ROESY and DOSY) in [D8]THF. The energetics of folding processes for the PBI dimer and trimer have been assessed by calculations applying various methods, particularly the semiempirical PM6-DH2 and the more sophisticated B97D approach, in which relevant dispersion corrections are included. These calculations corroborate the results of NMR spectroscopic studies. Folding features in the excited states of these PBI foldamers have been characterized by using time-resolved fluorescence and transient absorption spectroscopy in THF and CHCl3, exhibiting similar solvent-dependent behavior as observed for the ground state. Interestingly, photoinduced electron transfer (PET) process from electron-donating backbone to electron-deficient PBI core for extended, but not for folded, conformations was observed, which can be explained by a fast relaxation of excited PBI stacks in the folded conformation into fluorescent excimer states.

UR - http://www.scopus.com/inward/record.url?scp=84920140759&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84920140759&partnerID=8YFLogxK

U2 - 10.1002/chem.201405231

DO - 10.1002/chem.201405231

M3 - Article

VL - 21

SP - 615

EP - 630

JO - Chemistry - A European Journal

JF - Chemistry - A European Journal

SN - 0947-6539

IS - 2

ER -