TY  - INPR
A1  - Stennett, Tom E.
A1  - Bissinger, Philipp
A1  - Griesbeck, Stefanie
A1  - Ullrich, Stefan
A1  - Krummenacher, Ivo
A1  - Auth, Michael
A1  - Sperlich, Andreas
A1  - Stolte, Matthias
A1  - Radacki, Krzysztof
A1  - Yao, Chang-Jiang
A1  - Würthner, Frank
A1  - Steffen, Andreas
A1  - Marder, Todd B.
A1  - Braunschweig, Holger
T1  - Near-Infrared Quadrupolar Chromophores Combining Three-Coordinate Boron-Based Superdonor and Superacceptor Units
T2  - Angewandte Chemie, International Edition
N2  - In this work, two new quadrupolar A-π-D-π-A chromophores have been prepared featuring a strongly electron- donating diborene core and strongly electron-accepting dimesitylboryl F(BMes2) and bis(2,4,6-tris(trifluoromethyl)phenyl)boryl (BMes2) end groups. Analysis of the compounds by NMR spectroscopy, X-ray crystallography, cyclic voltammetry and UV-vis-NIR absorption and emission spectroscopy indicated that the compounds possess extended conjugated π-systems spanning their B4C8 cores. The combination of exceptionally potent π-donor (diborene) and π- acceptor (diarylboryl) groups, both based on trigonal boron, leads to very small HOMO-LUMO gaps, resulting in strong absorption in the near-IR region with maxima in THF at 840 and 1092 nm, respectively, and very high extinction coefficients of ca. 120,000 M-1cm-1. Both molecules also display weak near-IR fluorescence with small Stokes shifts.
KW  - boron
KW  - near-IR chromophores
KW  - conjugation
KW  - low-valent compounds
KW  - synthesis
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-180391
N1  - This is the pre-peer reviewed version of the following article: T. E. Stennett, P. Bissinger, S. Griesbeck, S. Ullrich, I. Krummenacher, M. Auth, A. Sperlich, M. Stolte, K. Radacki, C.-J. Yao, F. Wuerthner, A. Steffen, T. B. Marder, H. Braunschweig, Angew. Chem. Int. Ed. 2019, 58, 6449. , which has been published in final form at  https://doi.org/10.1002/anie.201900889. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.
ER  - 
TY  - JOUR
A1  - Mueller, Stefan
A1  - Lüttig, Julian
A1  - Malý, Pavel
A1  - Ji, Lei
A1  - Han, Jie
A1  - Moos, Michael
A1  - Marder, Todd B.
A1  - Bunz, Uwe H. F.
A1  - Dreuw, Andreas
A1  - Lambert, Christoph
A1  - Brixner, Tobias
T1  - Rapid multiple-quantum three-dimensional fluorescence spectroscopy disentangles quantum pathways
JF  - Nature Communications
N2  - Coherent two-dimensional spectroscopy is a powerful tool for probing ultrafast quantum dynamics in complex systems. Several variants offer different types of information but typically require distinct beam geometries. Here we introduce population-based three-dimensional (3D) electronic spectroscopy and demonstrate the extraction of all fourth- and multiple sixth-order nonlinear signal contributions by employing 125-fold (1⨯5⨯5⨯5) phase cycling of a four-pulse sequence. Utilizing fluorescence detection and shot-to-shot pulse shaping in single-beam geometry, we obtain various 3D spectra of the dianion of TIPS-tetraazapentacene, a fluorophore with limited stability at ambient conditions. From this, we recover previously unknown characteristics of its electronic two-photon state. Rephasing and nonrephasing sixth-order contributions are measured without additional phasing that hampered previous attempts using noncollinear geometries. We systematically resolve all nonlinear signals from the same dataset that can be acquired in 8 min. The approach is generalizable to other incoherent observables such as external photoelectrons, photocurrents, or photoions.
KW  - Atomic and molecular interactions with photons
KW  - Optical spectroscopy
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202529
VL  - 10
ER  - 
TY  - JOUR
A1  - Griesbeck, Stefanie
A1  - Michail, Evripidis
A1  - Rauch, Florian
A1  - Ogasawara, Hiroaki
A1  - Wang, Chenguang
A1  - Sato, Yoshikatsu
A1  - Edkins, Robert M.
A1  - Zhang, Zuolun
A1  - Taki, Masayasu
A1  - Lambert, Christoph
A1  - Yamaguchi, Shigehiro
A1  - Marder, Todd B.
T1  - 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
JF  - Chemistry – A European Journal
N2  - 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.
KW  - boranes
KW  - cell imaging
KW  - fluorescence
KW  - lysosome
KW  - two-photon excited fluorescence
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-212887
VL  - 25
IS  - 57
SP  - 13164
EP  - 13175
ER  -