28712
2022
eng
40
28
article
1
--
--
--
Methyl Viologens of Bis‐(4’‐Pyridylethynyl)Arenes – Structures, Photophysical and Electrochemical Studies, and their Potential Application in Biology
A series of bis‐(4’‐pyridylethynyl)arenes (arene=benzene, tetrafluorobenzene, and anthracene) were synthesized and their bis‐N‐methylpyridinium compounds were investigated as a class of π‐extended methyl viologens. Their structures were determined by single crystal X‐ray diffraction, and their photophysical and electrochemical properties (cyclic voltammetry), as well as their interactions with DNA/RNA were investigated. The dications showed bathochromic shifts in emission compared to the neutral compounds. The neutral compounds showed very small Stokes shifts, which are a little larger for the dications. All of the compounds showed very short fluorescence lifetimes (<4 ns). The neutral compound with an anthracene core has a quantum yield of almost unity. With stronger acceptors, the analogous bis‐N‐methylpyridinium compound showed a larger two‐photon absorption cross‐section than its neutral precursor. All of the dicationic compounds interact with DNA/RNA; while the compounds with benzene and tetrafluorobenzene cores bind in the grooves, the one with an anthracene core intercalates as a consequence of its large, condensed aromatic linker moiety, and it aggregates within the polynucleotide when in excess over DNA/RNA. Moreover, all cationic compounds showed highly specific CD spectra upon binding to ds‐DNA/RNA, attributed to the rare case of forcing the planar, achiral molecule into a chiral rotamer, and negligible toxicity toward human cell lines at ≤10 μM concentrations. The anthracene‐analogue exhibited intracellular accumulation within lysosomes, preventing its interaction with cellular DNA/RNA. However, cytotoxicity was evident at 1 μM concentration upon exposure to light, due to singlet oxygen generation within cells. These multi‐faceted features, in combination with its two‐photon absorption properties, suggest it to be a promising lead compound for development of novel light‐activated theranostic agents.
Chemistry – A European Journal
10.1002/chem.202200753
urn:nbn:de:bvb:20-opus-287126
2022-09-21T19:38:43+00:00
sword
swordwue
attachment; filename=deposit.zip
e4618c72c015fee17d2dcbec510f0f24
Chemistry – A European Journal 2022, 28(40):e202200753. DOI: 10.1002/chem.202200753
false
true
CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International
Goutam Kumar Kole
Marta Košćak
Anissa Amar
Dragomira Majhen
Ksenija Božinović
Zlatko Brkljaca
Matthias Ferger
Evripidis Michail
Sabine Lorenzen
Alexandra Friedrich
Ivo Krummenacher
Michael Moos
Holger Braunschweig
Abdou Boucekkine
Christoph Lambert
Jean‐François Halet
Ivo Piantanida
Klaus Müller‐Buschbaum
Todd B. Marder
eng
uncontrolled
cell imaging
eng
uncontrolled
DNA/RNA binding
eng
uncontrolled
methyl viologen
eng
uncontrolled
singlet oxygen
eng
uncontrolled
two-photon absorption
Chemie und zugeordnete Wissenschaften
open_access
Institut für Anorganische Chemie
Institut für Organische Chemie
Import
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/28712/Kole_Chemistry.pdf
20748
2020
eng
438-453
2
26
article
1
2020-07-06
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--
Synthesis, Photophysical and Electronic Properties of New Red-to-NIR Emitting Donor-Acceptor Pyrene Derivatives
We synthesized new pyrene derivatives with strong bis(para ‐methoxyphenyl)amine donors at the 2,7‐positions and n ‐azaacene acceptors at the K‐region of pyrene. The compounds possess a strong intramolecular charge transfer, leading to unusual properties such as emission in the red to NIR region (700 nm), which has not been reported before for monomeric pyrenes. Detailed photophysical studies reveal very long intrinsic lifetimes of >100 ns for the new compounds, which is typical for 2,7‐substituted pyrenes but not for K‐region substituted pyrenes. The incorporation of strong donors and acceptors leads to very low reduction and oxidation potentials, and spectroelectrochemical studies show that the compounds are on the borderline between localized Robin‐Day class‐II and delocalized Robin‐Day class‐III species.
Chemistry - A European Journal
10.1002/chem.201904219
urn:nbn:de:bvb:20-opus-207486
Chemistry - A European Journal (2020) 26(2):438-453. DOI: 10.1002/chem.201904219
false
true
CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International
Julia Merz
Maximilian Dietz
Yvonne Vonhausen
Frederik Wöber
Alexandra Friedrich
Daniel Sieh
Ivo Krummenacher
Holger Braunschweig
Michael Moos
Marco Holzapfel
Christoph Lambert
Todd B. Marder
eng
uncontrolled
orylation
eng
uncontrolled
K-region
eng
uncontrolled
luminescence
eng
uncontrolled
polycyclic aromatic hydrocarbons
eng
uncontrolled
redox
Anorganische Chemie
open_access
Institut für Anorganische Chemie
Institut für Organische Chemie
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/20748/Merz_Chemistry.pdf
28724
2022
eng
48
28
article
1
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Electron‐Rich EDOT Linkers in Tetracationic bis‐Triarylborane Chromophores: Influence on Water Stability, Biomacromolecule Sensing, and Photoinduced Cytotoxicity
Three novel tetracationic bis‐triarylboranes with 3,4‐ethylenedioxythiophene (EDOT) linkers, and their neutral precursors, showed significant red‐shifted absorption and emission compared to their thiophene‐containing analogues, with one of the EDOT‐derivatives emitting in the NIR region. Only the EDOT‐linked trixylylborane tetracation was stable in aqueous solution, indicating that direct attachment of a thiophene or even 3‐methylthiophene to the boron atom is insufficient to provide hydrolytic stability in aqueous solution. Further comparative analysis of the EDOT‐linked trixylylborane tetracation and its bis‐thiophene analogue revealed efficient photo‐induced singlet oxygen production, with the consequent biological implications. Thus, both analogues bind strongly to ds‐DNA and BSA, very efficiently enter living human cells, accumulate in several different cytoplasmic organelles with no toxic effect but, under intense visible light irradiation, they exhibit almost instantaneous and very strong cytotoxic effects, presumably attributed to singlet oxygen production. Thus, both compounds are intriguing theranostic agents, whose intracellular and probably intra‐tissue location can be monitored by strong fluorescence, allowing switching on of the strong bioactivity by well‐focused visible light.
Chemistry – A European Journal
10.1002/chem.202201130
urn:nbn:de:bvb:20-opus-287241
2022-09-21T22:15:31+00:00
sword
swordwue
attachment; filename=deposit.zip
74c0c0d457b87a57d3cf49325de013f5
Chemistry – A European Journal 2022, 28(48):e202201130: DOI: 10.1002/chem.202201130
false
true
CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International
Matthias Ferger
Chantal Roger
Eva Köster
Florian Rauch
Sabine Lorenzen
Ivo Krummenacher
Alexandra Friedrich
Marta Košćak
Davor Nestić
Holger Braunschweig
Christoph Lambert
Ivo Piantanida
Todd B. Marder
eng
uncontrolled
boranes
eng
uncontrolled
DNA/RNA sensors
eng
uncontrolled
fluorescent probes
eng
uncontrolled
singlet oxygen
eng
uncontrolled
theranostics
Chemie und zugeordnete Wissenschaften
open_access
Institut für Anorganische Chemie
Institut für Organische Chemie
Import
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/28724/CHEM_CHEM202201130.pdf
21783
2020
eng
12050
12059
52
26
article
1
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--
--
Synthesis, Photophysical and Electronic Properties of Mono‐, Di‐, and Tri‐Amino‐Substituted Ortho‐Perylenes, and Comparison to the Tetra‐Substituted Derivative
We synthesized a series of new mono‐, di‐, tri‐ and tetra‐substituted perylene derivatives with strong bis(para‐methoxyphenyl)amine (DPA) donors at the uncommon 2,5,8,11‐positions. The properties of our new donor‐substituted perylenes were studied in detail to establish a structure‐property relationship. Interesting trends and unusual properties are observed for this series of new perylene derivatives, such as a decreasing charge transfer (CT) character with increasing number of DPA moieties and individual reversible oxidations for each DPA moiety. Thus, (DPA)‐Per possesses one reversible oxidation while (DPA)\(_{4}\)‐Per has four. The mono‐ and di‐substituted derivatives display unusually large Stokes shifts not previously reported for perylenes. Furthermore, transient absorption measurements of the new derivatives reveal an excited state with lifetimes of several hundred microseconds, which sensitizes singlet oxygen with quantum yields of up to 0.83.
Chemistry – A European Journal
10.1002/chem.202001475
urn:nbn:de:bvb:20-opus-217835
2020-12-07T10:28:13+00:00
sword
swordwue
attachment; filename=deposit.zip
5f3a65ca54d63b5c3985f1a6bf07bb91
Chemistry – A European Journal 2020, 26(52):12050-12059. DOI: 10.1002/chem.202001475
false
true
CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International
Julia Merz
Lena Dietrich
Jörn Nitsch
Ivo Krummenacher
Holger Braunschweig
Michael Moos
David Mims
Christoph Lambert
Todd B. Marder
eng
uncontrolled
borylation
eng
uncontrolled
intersystem crossing
eng
uncontrolled
luminescence
eng
uncontrolled
polycyclic aromatic hydrocarbon
eng
uncontrolled
triarylamine
Chemie und zugeordnete Wissenschaften
open_access
Institut für Anorganische Chemie
Institut für Organische Chemie
Import
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/21783/CHEM_CHEM202001475.pdf
20816
2019
eng
15463-15471
68
25
article
1
2020-07-13
--
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Luminescent Mono-, Di-, and Tri-radicals: Bridging Polychlorinated Triarylmethyl Radicals by Triarylamines and Triarylboranes
Up to three polychlorinated pyridyldiphenylmethyl radicals bridged by a triphenylamine carrying electron withdrawing (CN), neutral (Me), or donating (OMe) groups were synthesized and analogous radicals bridged by tris(2,6‐dimethylphenyl)borane were prepared for comparison. All compounds were as stable as common closed‐shell organic compounds and showed significant fluorescence upon excitation. Electronic, magnetic, absorption, and emission properties were examined in detail, and experimental results were interpreted using DFT calculations. Oxidation potentials, absorption and emission energies could be tuned depending on the electron density of the bridges. The triphenylamine bridges mediated intramolecular weak antiferromagnetic interactions between the radical spins, and the energy difference between the high spin and low spin states was determined by temperature dependent ESR spectroscopy and DFT calculations. The fluorescent properties of all radicals were examined in detail and revealed no difference for high and low spin states which facilitates application of these dyes in two‐photon absorption spectroscopy and OLED devices.
Chemistry - A European Journal
10.1002/chem.201903007
urn:nbn:de:bvb:20-opus-208162
Chemistry - A European Journal (2019) 25(68):15463-15471. DOI: 10.1002/chem.201903007
false
true
CC BY-NC: Creative-Commons-Lizenz: Namensnennung, Nicht kommerziell 4.0 International
Yohei Hattori
Evripidis Michail
Alexander Schmiedel
Michael Moos
Marco Holzapfel
Ivo Krummenacher
Holger Braunschweig
Ulrich Müller
Jens Pflaum
Christoph Lambert
eng
uncontrolled
density functional calculations
eng
uncontrolled
fluorescence
eng
uncontrolled
NIR OLED
eng
uncontrolled
radical
eng
uncontrolled
two-photon absorption
Chemie und zugeordnete Wissenschaften
open_access
Physikalisches Institut
Institut für Anorganische Chemie
Institut für Organische Chemie
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/20816/Hattori_Chemistry.pdf
25653
2021
eng
23656-23660
60
article
1
2022-02-12
--
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Zinc-[7]helicenocyanine and its discrete π-stacked homochiral Dimer
In this communication, we demonstrate a novel approach to prepare a discrete dimer of chiral phthalocyanine (Pc) by exploiting the flexible molecular geometry of helicenes, which enables structural interlocking and strong aggregation tendency of Pcs. Synthesized [7]helicene-Pc hybrid molecular structure, zinc-[7]helicenocyanine (Zn-7HPc), exclusively forms a stable dimeric pair consisting of two homochiral molecules. The dimerization constants were estimated to be as high as 8.96×10\(^6\) M\(^{−1}\) and 3.42×107 M\(^{−1}\) in THF and DMSO, respectively, indicating remarkable stability of dimer. In addition, Zn\(^{-7}\)HPc exhibited chiral self-sorting behavior, which resulted in preferential formation of a homochiral dimer also in the racemic sample. Two phthalocyanine subunits in the dimeric form strongly communicate with each other as revealed by a large comproportionation constant and observation of an IV-CT band for the thermodynamically stable mixed-valence state.
Angewandte Chemie International Edition
10.1002/anie.202109380
urn:nbn:de:bvb:20-opus-256534
publish
Angewandte Chemie International Edition (2021) 60:44, 23656–23660. DOI: 10.1002/anie.202109380
false
true
CC BY-NC-ND: Creative-Commons-Lizenz: Namensnennung, Nicht kommerziell, Keine Bearbeitungen 4.0 International
Fangyuan Zhang
Krzysztof Radacki
Holger Braunschweig
Christoph Lambert
Prince Ravat
eng
uncontrolled
organic chemistry
eng
uncontrolled
supramolecular assembly
eng
uncontrolled
chirality
eng
uncontrolled
helicenes
eng
uncontrolled
homochiral dimer
eng
uncontrolled
phthalocyanines
Organische Chemie
open_access
Institut für Anorganische Chemie
Institut für Organische Chemie
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/25653/Angew_Chem_Int_Ed_2021_Zhang.pdf