@article{Pikovskij2021, author = {Pikovskij, Arkadij}, title = {Transition to synchrony in chiral active particles}, series = {Journal of physics. Complexity}, volume = {2}, journal = {Journal of physics. Complexity}, number = {2}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {2632-072X}, doi = {10.1088/2632-072X/abdadb}, pages = {8}, year = {2021}, abstract = {I study deterministic dynamics of chiral active particles in two dimensions. Particles are considered as discs interacting with elastic repulsive forces. An ensemble of particles, started from random initial conditions, demonstrates chaotic collisions resulting in their normal diffusion. This chaos is transient, as rather abruptly a synchronous collisionless state establishes. The life time of chaos grows exponentially with the number of particles. External forcing (periodic or chaotic) is shown to facilitate the synchronization transition.}, language = {en} } @article{HolecRybačekVaceketal.2019, author = {Holec, Jan and Ryb{\´a}ček, Jiř{\´i} and Vacek, Jaroslav and Karras, Manfred and Bedn{\´a}rov{\´a}, Lucie and Budesinsky, Milos and Slusna, Michaela and Holy, Petr and Schmidt, Bernd and Star{\´a}, Irena G. and Star{\´y}, Ivo}, title = {Chirality-Controlled Self-Assembly of Amphiphilic Dibenzo[6]helicenes into Langmuir-Blodgett Thin Films}, series = {Chemistry - a European journal}, volume = {25}, journal = {Chemistry - a European journal}, number = {49}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0947-6539}, doi = {10.1002/chem.201901695}, pages = {11494 -- 11502}, year = {2019}, abstract = {Racemic and highly enantioenriched 3-methoxycarbonyl, 3-carboxy, and 3-hydroxymethyl derivatives of dibenzo[6]helicene were prepared. The Langmuir layers of these helicenes were formed at the air-water interface and transferred onto solid substrates to afford Langmuir-Blodgett films, which were then studied by ambient atomic force microscopy and (chir)optical spectroscopy. Significant differences were found in the behaviour of the Langmuir layers as well as in the morphology, UV/Vis, electronic circular dichroism (ECD), and fluorescence spectra of the Langmuir-Blodgett thin films depending on the molecular chirality and nature of the polar group. The experimental results were supported by molecular dynamics simulations.}, language = {en} } @misc{BringmannMutanyattaComarMaksimenkaetal.2008, author = {Bringmann, Gerhard and Mutanyatta-Comar, Joan and Maksimenka, Katja and Wanjohi, John M. and Heydenreich, Matthias and Brun, Reto and M{\"u}ller, Werner E. G. and Peter, Martin and Midiwo, Jacob O. and Yenesew, Abiy}, title = {Joziknipholones A and B : the First Dimeric Phenylanthraquinones, from the Roots of Bulbine frutescens}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-42638}, year = {2008}, abstract = {From the roots of the African plant Bulbine frutescens (Asphodelaceae), two unprecedented novel dimeric phenylanthraquinones, named joziknipholones A and B, possessing axial and centrochirality, were isolated, together with six known compounds. Structural elucidation of the new metabolites was achieved by spectroscopic and chiroptical methods, by reductive cleavage of the central bond between the monomeric phenylanthraquinone and -anthrone portions with sodium dithionite, and by quantum chemical CD calculations. Based on the recently revised absolute axial configuration of the parent phenylanthraquinones, knipholone and knipholone anthrone, the new dimers were attributed to possess the P-configuration (i.e., with the acetyl portions below the anthraquinone plane) at both axes in the case of joziknipholone A, whereas in joziknipholone B, the knipholone part was found to be M-configured. Joziknipholones A and B are active against the chloroquine resistant strain K1 of the malaria pathogen, Plasmodium falciparum, and show moderate activity against murine leukemic lymphoma L5178y cells.}, language = {en} }