@article{BrueningWehnerHausneretal.2016,
  author    = {Br{\"u}ning, Christoph and Wehner, Johannes and Hausner, Julian and Wenzel, Michael and Engel, Volker},
  title     = {Exciton dynamics in perturbed vibronic molecular aggregates},
  series = {Structural Dynamics},
  volume    = {3},
  journal   = {Structural Dynamics},
  doi       = {10.1063/1.4936127},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126085},
  pages     = {043201},
  year      = {2016},
  abstract  = {A site specific perturbation of a photo-excited molecular aggregate can lead to a localization of excitonic energy. We investigate this localization dynamics for laser-prepared excited states. Changing the parameters of the electric field significantly influences the exciton localization which offers the possibility for a selective control of this process. This is demonstrated for aggregates possessing a single vibrational degree of freedom per monomer unit. It is shown that the effects identified for the molecular dimer can be generalized to larger aggregates with a high density of vibronic states.},
  language  = {en}
}
@article{EngelAlbertSchubert2013,
  author    = {Engel, Volker and Albert, Julian and Schubert, Alexander},
  title     = {Two-dimensional vibronic spectroscopy of molecular predissociation},
  series = {New Journal of Physics},
  journal   = {New Journal of Physics},
  doi       = {10.1088/1367-2630/15/2/025008},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96199},
  year      = {2013},
  abstract  = {We calculate two-dimensional (2D) spectra reflecting the time-dependent electronic predissociation of a diatomic molecule. The laser-excited electronic state is coupled non-adiabatically to a fragment channel, leading to the decay of the prepared quasi-bound states. This decay can be monitored by the three-pulse configuration employed in optical 2D spectroscopy. It is shown that in this way it is possible to state-selectively characterize the time-dependent population of resonance states with different lifetimes. A model of the NaI molecule serves as a numerical example.},
  language  = {en}
}
@article{KleinBarthelsJoheetal.2020,
  author    = {Klein, Philipp and Barthels, Fabian and Johe, Patrick and Wagner, Annika and Tenzer, Stefan and Distler, Ute and Le, Thien Anh and Schmid, Paul and Engel, Volker and Engels, Bernd and Hellmich, Ute A. and Opatz, Till and Schirmeister, Tanja},
  title     = {Naphthoquinones as covalent reversible inhibitors of cysteine proteases — studies on inhibition mechanism and kinetics},
  series = {Molecules},
  volume    = {25},
  journal   = {Molecules},
  number    = {9},
  issn      = {1420-3049},
  doi       = {10.3390/molecules25092064},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203791},
  year      = {2020},
  abstract  = {The facile synthesis and detailed investigation of a class of highly potent protease inhibitors based on 1,4-naphthoquinones with a dipeptidic recognition motif (HN-l-Phe-l-Leu-OR) in the 2-position and an electron-withdrawing group (EWG) in the 3-position is presented. One of the compound representatives, namely the acid with EWG = CN and with R = H proved to be a highly potent rhodesain inhibitor with nanomolar affinity. The respective benzyl ester (R = Bn) was found to be hydrolyzed by the target enzyme itself yielding the free acid. Detailed kinetic and mass spectrometry studies revealed a reversible covalent binding mode. Theoretical calculations with different density functionals (DFT) as well as wavefunction-based approaches were performed to elucidate the mode of action.},
  language  = {en}
}
@article{SaalfrankFantuzziKupferetal.2020,
  author    = {Saalfrank, Christian and Fantuzzi, Felipe and Kupfer, Thomas and Ritschel, Benedikt and Hammond, Kai and Krummenacher, Ivo and Bertermann, R{\"u}diger and Wirthensohn, Raphael and Finze, Maik and Schmid, Paul and Engel, Volker and Engels, Bernd and Braunschweig, Holger},
  title     = {cAAC-Stabilized 9,10-diboraanthracenes—Acenes with Open-Shell Singlet Biradical Ground States},
  series = {Angewandte Chemie International Edition},
  volume    = {59},
  journal   = {Angewandte Chemie International Edition},
  number    = {43},
  doi       = {10.1002/anie.202008206},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-217795},
  pages     = {19338 -- 19343},
  year      = {2020},
  abstract  = {Narrow HOMO-LUMO gaps and high charge-carrier mobilities make larger acenes potentially high-efficient materials for organic electronic applications. The performance of such molecules was shown to significantly increase with increasing number of fused benzene rings. Bulk quantities, however, can only be obtained reliably for acenes up to heptacene. Theoretically, (oligo)acenes and (poly)acenes are predicted to have open-shell singlet biradical and polyradical ground states, respectively, for which experimental evidence is still scarce. We have now been able to dramatically lower the HOMO-LUMO gap of acenes without the necessity of unfavorable elongation of their conjugated π system, by incorporating two boron atoms into the anthracene skeleton. Stabilizing the boron centers with cyclic (alkyl)(amino)carbenes gives neutral 9,10-diboraanthracenes, which are shown to feature disjointed, open-shell singlet biradical ground states.},
  language  = {en}
}
@article{SaalfrankFantuzziKupferetal.2020,
  author    = {Saalfrank, Christian and Fantuzzi, Felipe and Kupfer, Thomas and Ritschel, Benedikt and Hammond, Kai and Krummenacher, Ivo and Bertermann, R{\"u}diger and Wirthensohn, Raphael and Finze, Maik and Schmid, Paul and Engel, Volker and Engels, Bernd and Braunschweig, Holger},
  title     = {cAAC-stabilisierte 9,10-Diboraanthracene - offenschalige Singulettbiradikale},
  series = {Angewandte Chemie},
  volume    = {132},
  journal   = {Angewandte Chemie},
  number    = {43},
  doi       = {10.1002/ange.202008206},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218582},
  pages     = {19502 -- 19507},
  year      = {2020},
  abstract  = {Geringe HOMO-LUMO-Abst{\"a}nde und eine hohe Ladungstr{\"a}germobilit{\"a}t pr{\"a}destinieren die h{\"o}heren Acene f{\"u}r Anwendungen im Bereich der Organoelektronik. Die Leistungsf{\"a}higkeit derartiger Verbindungen steigt hierbei dramatisch mit der Anzahl anellierter Benzolringe. Gr{\"o}ßere Acenmengen sind synthetisch bisher jedoch nur f{\"u}r Acene bis Heptacen verl{\"a}sslich zug{\"a}nglich. Theoretischen Studien zufolge besitzen (Oligo)acene offenschalige Singulettbiradikal- und (Poly)acene polyradikalische Grundzust{\"a}nde. Eindeutige experimentelle Belege f{\"u}r diese Vorhersagen sind hingegen {\"a}ußerst selten. Durch den Einbau von zwei Boratomen in das Anthracengrundger{\"u}st konnten wir den HOMO-LUMO-Abstand von Acenen dramatisch verringern und zwar ohne die Notwendigkeit einer Ausweitung des konjugierten π-Systems. Stabilisierung der Borzentren durch cyclische (Alkyl)(amino)carbene lieferte hierbei neutrale 9,10-Diboraanthracene mit disjunkten, offenschaligen Singulettbiradikal-Grundzust{\"a}nden.},
  language  = {en}
}
@article{SchmidtFantuzziKlopfetal.2021,
  author    = {Schmidt, Paul and Fantuzzi, Felipe and Klopf, Jonas and Schr{\"o}der, Niklas B. and Dewhurst, Rian D. and Braunschweig, Holger and Engel, Volker and Engels, Bernd},
  title     = {Twisting versus delocalization in CAAC- and NHC-stabilized boron-based biradicals: the roles of sterics and electronics},
  series = {Chemistry - A European Journal},
  volume    = {27},
  journal   = {Chemistry - A European Journal},
  number    = {16},
  doi       = {10.1002/chem.202004619},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256636},
  pages     = {5160-5170},
  year      = {2021},
  abstract  = {Twisted boron-based biradicals featuring unsaturated C\(_2\)R\(_2\) (R=Et, Me) bridges and stabilization by cyclic (alkyl)(amino)carbenes (CAACs) were recently prepared. These species show remarkable geometrical and electronic differences with respect to their unbridged counterparts. Herein, a thorough computational investigation on the origin of their distinct electrostructural properties is performed. It is shown that steric effects are mostly responsible for the preference for twisted over planar structures. The ground-state multiplicity of the twisted structure is modulated by the σ framework of the bridge, and different R groups lead to distinct multiplicities. In line with the experimental data, a planar structure driven by delocalization effects is observed as global minimum for R=H. The synthetic elusiveness of C\(_2\)R\(_2\)-bridged systems featuring N-heterocyclic carbenes (NHCs) was also investigated. These results could contribute to the engineering of novel main group biradicals.},
  language  = {en}
}
@article{SuessWehnerDostaletal.2019,
  author    = {S{\"u}ß, Jasmin and Wehner, Johannes G. and Dost{\´a}l, Jakub and Engel, Volker and Brixner, Tobias},
  title     = {Mapping of exciton-exciton annihilation in a molecular dimer via fifth-order femtosecond two-dimensional spectroscopy},
  series = {Journal of Physical Chemistry Letters},
  volume    = {150},
  journal   = {Journal of Physical Chemistry Letters},
  number    = {10},
  doi       = {10.1063/1.5086151},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-178420},
  pages     = {104304},
  year      = {2019},
  abstract  = {We present a theoretical study on exciton-exciton annihilation (EEA) in a molecular dimer. This process is monitored using a fifth-order coherent two-dimensional (2D) spectroscopy as was recently proposed by Dost{\´a}l et al. [Nat. Commun. 9, 2466 (2018)]. Using an electronic three-level system for each monomer, we analyze the different paths which contribute to the 2D spectrum. The spectrum is determined by two entangled relaxation processes, namely, the EEA and the direct relaxation of higher lying excited states. It is shown that the change of the spectrum as a function of a pulse delay can be linked directly to the presence of the EEA process.},
  subject      = {Exziton},
  language  = {en}
}
@unpublished{SuessWehnerDostaletal.2019,
  author    = {S{\"u}ß, Jasmin and Wehner, Johannes G. and Dost{\´a}l, Jakub and Engel, Volker and Brixner, Tobias},
  title     = {Mapping of exciton-exciton annihilation in a molecular dimer via fifth-order femtosecond two-dimensional spectroscopy},
  series = {Journal of Physical Chemistry Letters},
  journal   = {Journal of Physical Chemistry Letters},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-178482},
  year      = {2019},
  abstract  = {We present a theoretical study on exciton-exciton annihilation (EEA) in a molecular dimer. This process is monitored using a fifth-order coherent two-dimensional (2D) spectroscopy as was recently proposed by Dost{\´a}l et al. [Nat. Commun. 9, 2466 (2018)]. Using an electronic three-level system for each monomer, we analyze the different paths which contribute to the 2D spectrum. The spectrum is determined by two entangled relaxation processes, namely, the EEA and the direct relaxation of higher lying excited states. It is shown that the change of the spectrum as a function of a pulse delay can be linked directly to the presence of the EEA process.},
  subject      = {Exziton},
  language  = {en}
}