@unpublished{StennettBissingerGriesbecketal.2019,
  author    = {Stennett, Tom E. and Bissinger, Philipp and Griesbeck, Stefanie and Ullrich, Stefan and Krummenacher, Ivo and Auth, Michael and Sperlich, Andreas and Stolte, Matthias and Radacki, Krzysztof and Yao, Chang-Jiang and W{\"u}rthner, Frank and Steffen, Andreas and Marder, Todd B. and Braunschweig, Holger},
  title     = {Near-Infrared Quadrupolar Chromophores Combining Three-Coordinate Boron-Based Superdonor and Superacceptor Units},
  series = {Angewandte Chemie, International Edition},
  journal   = {Angewandte Chemie, International Edition},
  doi       = {10.1002/anie.201900889},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-180391},
  year      = {2019},
  abstract  = {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.},
  language  = {en}
}
@article{LindlGuoKrummenacheretal.2021,
  author    = {Lindl, Felix and Guo, Xueying and Krummenacher, Ivo and Rauch, Florian and Rempel, Anna and Paprocki, Valerie and Dellermann, Theresa and Stennett, Tom E. and Lamprecht, Anna and Br{\"u}ckner, Tobias and Radacki, Krzysztof and B{\´e}langer-Chabot, Guillaume and Marder, Todd B. and Lin, Zhenyang and Braunschweig, Holger},
  title     = {Rethinking Borole Cycloaddition Reactivity},
  series = {Chemistry—A European Journal},
  volume    = {27},
  journal   = {Chemistry—A European Journal},
  number    = {43},
  doi       = {10.1002/chem.202101290},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256888},
  pages     = {11226-11233},
  year      = {2021},
  abstract  = {Boroles are attracting broad interest for their myriad and diverse applications, including in synthesis, small molecule activation and functional materials. Their properties and reactivity are closely linked to the cyclic conjugated diene system, which has been shown to participate in cycloaddition reactions, such as the Diels-Alder reaction with alkynes. The reaction steps leading to boranorbornadienes, borepins and tricyclic boracyclohexenes from the thermal reaction of boroles with alkynes are seemingly well understood as judged from the literature. Herein, we question the long-established mechanistic picture of pericyclic rearrangements by demonstrating that seven-membered borepins (i. e., heptaphenylborepin and two derivatives substituted with a thienyl and chloride substituent on boron) exist in a dynamic equilibrium with the corresponding bicyclic boranorbornadienes, the direct Diels-Alder products, but are not isolable products from the reactions. Heating gradually converts the isomeric mixtures into fluorescent tricyclic boracyclohexenes, the most stable isomers in the series. Results from mechanistic DFT calculations reveal that the tricyclic compounds derive from the boranorbornadienes and not the borepins, which were previously believed to be intermediates in purely pericyclic processes.},
  language  = {en}
}