19871
2019
eng
preprint
1
2020-01-27
--
--
Dynamic exciton localisation in a pyrene-BODIPY-pyrene dye conjugate
The photophysics of a molecular triad consisting of a BODIPY dye and two pyrene chromophores attached in 2-position are investigated by steady state and fs-time resolved transient absorption spectroscopy as well as by field induced surface hopping (FISH) simulations. While the steady state measurements indicate moderate chromophore interactions within the triad, the time resolved measurements show upon pyrene excitation a delocalised excited state which localises onto the BODIPY chromophore with a time constant of 0.12 ps. This could either be interpreted as an internal conversion process within the excitonically coupled chromophores or as an energy transfer from the pyrenes to the BODIPY dye. The analysis of FISH-trajectories reveals an oscillatory behaviour where the excitation hops between the pyrene units and the BODIPY dye several times until finally they become localised on the BODIPY chromophore within 100 fs. This is accompanied by an ultrafast nonradiative relaxation within the excitonic manifold mediated by the nonadiabatic coupling. Averaging over an ensemble of trajectories allowed us to simulate the electronic state population dynamics and determine the time constants for the nonradiative transitions that mediate the ultrafast energy transfer and exciton localisation on BODIPY.
Physical Chemistry Chemical Physics
https://doi.org/10.1039/C9CP00908F
urn:nbn:de:bvb:20-opus-198718
Accepted manuscript
Physical Chemistry Chemical Physics, 2019,21, 9013-9025. https://doi.org/10.1039/C9CP00908F
646737
false
true
Deutsches Urheberrecht
Nina Auerhammer
Alexander Schulz
Alexander Schmiedel
Marco Holzapfel
Joscha Hoche
Merle I. S. Röhr
Roland Mitric
Christoph Lambert
eng
uncontrolled
Exciton localization dynamics
Physikalische Chemie
open_access
Institut für Physikalische und Theoretische Chemie
OpenAIRE
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/19871/mitric_roland_bodipy_triade.pdf
15960
2015
eng
preprint
1
2018-03-22
--
--
Energy Transfer Between Squaraine Polymer Sections: From helix to zig-zag and All the Way Back
Joint experimental and theoretical study of the absorption spectra of squaraine polymers in solution provide evidence that two different conformations are present in solution: a helix and a zig-zag structure. This unique situation allows investigating ultrafast energy transfer processes between different structural segments within a single polymer chain in solution. The understanding of the underlying dynamics is of fundamental importance for the development of novel materials for light-harvesting and optoelectronic applications. We combine here femtosecond transient absorption spectroscopy with time-resolved 2D electronic spectroscopy showing that ultrafast energy transfer within the squaraine polymer chains proceeds from initially excited helix segments to zig-zag segments or vice versa, depending on the solvent as well as on the excitation wavenumber. These observations contrast other conjugated polymers such as MEH-PPV where much slower intrachain energy transfer was reported. The reason for the very fast energy transfer in squaraine polymers is most likely a close matching of the density of states between donor and acceptor polymer segments because of very small reorganization energy in these cyanine-like chromophores.
Journal of the American Chemical Society
10.1021/jacs.5b03644
http://dx.doi.org/10.1021/jacs.5b03644
urn:nbn:de:bvb:20-opus-159607
This document is the unedited Author's version of a Submitted Work that war subsequently accepted for publication in Journal of the American Chemical Society, copyright American Chemical Society after peer review. To access the final edited and published work see doi:10.1021/jacs.5b03644.
Journal of the American Chemical Society, 2015, 137 (24), pp 7851–7861 DOI: 10.1021/jacs.5b03644
Center for Nanosystems Chemistry (CNC), Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
Deutsches Urheberrecht
Christoph Lambert
Sebastian F. Völker
Federico Koch
Alexander Schmiedel
Marco Holzapfel
Alexander Humeniuk
Merle I. S. Röhr
Roland Mitric
Tobias Brixner
eng
uncontrolled
energy transfer dynamics
eng
uncontrolled
squaraine polymer
Physikalische Chemie
ATOMIC AND MOLECULAR PHYSICS
open_access
Institut für Organische Chemie
Institut für Physikalische und Theoretische Chemie
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/15960/Lambert_et_al_Squaraine_Polymer_Sections_JACS_submitted_version.pdf
19104
2016
eng
2350-2360
4
18
article
1
2019-10-31
--
--
Energy transfer and formation of long-lived \(^3\)MLCT states in multimetallic complexes with extended highly conjugated bis-terpyridyl ligands
Multimetallic complexes with extended and highly conjugated bis-2,2':6',2''-terpyridyl bridging ligands, which present building blocks for coordination polymers, are investigated with respect to their ability to act as light-harvesting antennae. The investigated species combine Ru(II)- with Os(II)- and Fe(II)-terpyridyl chromophores, the latter acting as energy sinks. Due to the extended conjugated system the ligands are able to prolong the lifetime of the \(^3\)MLCT states compared to unsubstituted terpyridyl species by delocalization and energetic stabilization of the \(^3\)MLCT states. This concept is applied for the first time to Fe(II) terpyridyl species and results in an exceptionally long lifetime of 23 ps for the Fe(II) \(^3\)MLCT state. While partial energy (>80%) transfer is observed between the Ru(II) and Fe(II) centers with a time-constant of 15 ps, excitation energy is transferred completely from the Ru(II) to the Os(II) center within the first 200 fs after excitation.
Physical Chemistry Chemical Physics
10.1039/c5cp04447b
urn:nbn:de:bvb:20-opus-191041
Physical Chemistry Chemical Physics (2016) 18:4, S. 2350-2360. https://doi.org/10.1039/c5cp04447b
LaserLab Europe (LLC001917)
true
true
Maria Wächtler
Joachim Kübel
Kevin Barthelmes
Andreas Winter
Alexander Schmiedel
Torbjörn Pascher
Christoph Lambert
Ulrich S. Schubert
Benjamin Dietzek
eng
uncontrolled
polypyridyl complexes
eng
uncontrolled
bis-terpyridyl ligands
eng
uncontrolled
multimetallic complexes
eng
uncontrolled
metal-to-ligand charge transfer (MLCT)
eng
uncontrolled
RU-(II) complexes
eng
uncontrolled
Ru(II)–Fe(II)–Ru(II) complex
Organische Chemie
open_access
Institut für Organische Chemie
OpenAIRE
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/19104/Waechtler_PhysicalChemistryChemicalPhysics_2016.pdf
18829
2016
eng
16404-16413
24
18
article
1
2019-10-04
--
--
Cooperative enhancement versus additivity of two-photon-absorption cross sections in linear and branched squaraine superchromophores
The linear and nonlinear optical properties of a series of oligomeric squaraine dyes were investigated by one-photon absorption spectroscopy (1PA) and two-photon absorption (2PA) induced fluorescence spectroscopy. The superchromophores are based on two indolenine squaraine dyes with transoid (SQA) and cisoid configuration (SQB). Using these monomers, linear dimers and trimers as well as star-shaped trimers and hexamers with benzene or triphenylamine cores were synthesised and investigated. The red-shifted and intensified 1PA spectra of all superchromophores could well be explained by exciton coupling theory. In the linear chromophore arrangements we also found superradiance of fluorescence but not in the branched systems. Furthermore, the 2PA showed enhanced cross sections for the linear oligomers but only additivity for the branched systems. This emphasizes that the enhancement of the 2PA cross section in the linear arrangements is probably caused by orbital interactions of higher excited configurations.
Physical Chemistry Chemical Physics
10.1039/c6cp02312f
urn:nbn:de:bvb:20-opus-188299
Physical Chemistry Chemical Physics (2016) 18:24, 16404-16413. https://doi.org/10.1039/c6cp02312f
false
true
Harald Ceyman
Arnulf Rosspeintner
Maximilian H. Schreck
Carina Mützel
Andreas Stoy
Eric Vauthey
Christoph Lambert
eng
uncontrolled
2-photon absorption
eng
uncontrolled
Vibronic contributions
eng
uncontrolled
One-photon
eng
uncontrolled
Molecules
eng
uncontrolled
Intensity
eng
uncontrolled
Multibranched structures
eng
uncontrolled
Optical properties
eng
uncontrolled
Dyes
eng
uncontrolled
Chromophores
eng
uncontrolled
Design
Organische Chemie
open_access
Institut für Organische Chemie
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/18829/Ceymann_PysicalChemistryChemicalPhysics_2016.pdf
5486
1993
eng
article
1
2012-01-26
--
--
“Inverted” Sodium-Lithium Electronegativity: Polarity and Metalation Energies of Organic and Inorganic Alkali-Metal Compounds
No abstract available
urn:nbn:de:bvb:20-opus-60054
6005
In: Organometallics (1993) 12, S. 853 - 859.
Deutsches Urheberrecht
Christoph Lambert
Martin Kaupp
Paul von Rague Schleyer
deu
swd
Anorganische Chemie
Chemie und zugeordnete Wissenschaften
open_access
Institut für Anorganische Chemie
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/5486/Kaupp13.pdf
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
--
--
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
--
--
--
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
21288
2019
eng
13164
13175
57
25
article
1
--
--
--
The Effect of Branching on the One‐ and Two‐Photon Absorption, Cell Viability, and Localization of Cationic Triarylborane Chromophores with Dipolar versus Octupolar Charge Distributions for Cellular Imaging
Two different chromophores, namely a dipolar and an octupolar system, were prepared and their linear and nonlinear optical properties as well as their bioimaging capabilities were compared. Both contain triphenylamine as the donor and a triarylborane as the acceptor, the latter modified with cationic trimethylammonio groups to provide solubility in aqueous media. The octupolar system exhibits a much higher two‐photon brightness, and also better cell viability and enhanced selectivity for lysosomes compared with the dipolar chromophore. Furthermore, both dyes were applied in two‐photon excited fluorescence (TPEF) live‐cell imaging.
Chemistry – A European Journal
10.1002/chem.201902461
urn:nbn:de:bvb:20-opus-212887
swordwue
2020-10-07T01:32:34+00:00
attachment; filename=deposit.zip
c077e8ca06930445503c3611f164b8c7
Chemistry – A European Journal 2019, 25(57):13164–13175. DOI: 10.1002/chem.201902461
false
true
CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International
Stefanie Griesbeck
Evripidis Michail
Florian Rauch
Hiroaki Ogasawara
Chenguang Wang
Yoshikatsu Sato
Robert M. Edkins
Zuolun Zhang
Masayasu Taki
Christoph Lambert
Shigehiro Yamaguchi
Todd B. Marder
eng
uncontrolled
boranes
eng
uncontrolled
cell imaging
eng
uncontrolled
fluorescence
eng
uncontrolled
lysosome
eng
uncontrolled
two-photon excited fluorescence
Chemie und zugeordnete Wissenschaften
open_access
Institut für Anorganische Chemie
Institut für Organische Chemie
Import
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/21288/CHEM_CHEM201902461.pdf
21783
2020
eng
12050
12059
52
26
article
1
--
--
--
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