TY  - JOUR
A1  - Full, Julian
A1  - Panchal, Santosh P.
A1  - Götz, Julian
A1  - Krause, Ana‐Maria
A1  - Nowak‐Król, Agnieszka
T1  - Modulare Synthese helikal‐chiraler Organobor‐Verbindungen: Ausschnitte verlängerter Helices
JF  - Angewandte Chemie
N2  - Zwei Arten helikal-chiraler Verbindungen mit einem oder zwei Boratomen wurden nach einem modularen Ansatz synthetisiert. Die Bildung der helikalen Strukturen erfolgte durch Einführung von Bor in flexible Biaryl- bzw. Triaryl-Vorstufen, hergestellt aus kleinen achiralen Bausteinen. Die durchgehend ortho-fusionierten Azabora[7]helicene zeichnen sich dabei durch außergewöhnliche Konfigurationsstabilität, blaue oder grüne Fluoreszenz in Lösung mit Quantenausbeuten (Φ\(_{fl}\)) von 18–24 %, grüne oder gelbe Emission im Festkörper (Φ\(_{fl}\) bis zu 23 %) und starke chiroptische Resonanz mit großen Anisotropiefaktoren von bis zu 1.12×10\(^{-2}\) aus. Azabora[9]helicene, aufgebaut aus winkelförmig sowie linear angeordneten Ringen, sind blaue Emitter mit Φ\(_{fl}\) von bis zu 47 % in CH\(_{2}\)Cl\(_{2}\) und 25 % im Festkörper. DFT-Rechnungen zeigen, dass ihre P-M-Interkonversion über einen komplexeren Weg verläuft als im Fall von H1. Röntgenstrukturanalyse von Einkristallen zeigt deutliche Unterschiede in der Packungsanordnung von Methyl- und Phenylderivaten auf. Die Moleküle werden als Primärstrukturen verlängerter Helices vorgeschlagen.
KW  - Chiralität
KW  - Fluoreszenz
KW  - Helicen
KW  - Organobor
KW  - Zirkulardichroismus
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224385
VL  - 133
IS  - 8
SP  - 4396
EP  - 4403
ER  - 
TY  - JOUR
A1  - Full, Julian
A1  - Panchal, Santosh P.
A1  - Götz, Julian
A1  - Krause, Ana‐Maria
A1  - Nowak‐Król, Agnieszka
T1  - Modular Synthesis of Organoboron Helically Chiral Compounds: Cutouts from Extended Helices
JF  - Angewandte Chemie International Edition
N2  - Two types of helically chiral compounds bearing one and two boron atoms were synthesized by a modular approach. Formation of the helical scaffolds was executed by the introduction of boron to flexible biaryl and triaryl derived from small achiral building blocks. All‐ortho‐fused azabora[7]helicenes feature exceptional configurational stability, blue or green fluorescence with quantum yields (Φ\(_{fl}\)) of 18–24 % in solution, green or yellow solid‐state emission (Φ\(_{fl}\) up to 23 %), and strong chiroptical response with large dissymmetry factors of up to 1.12×10\(^{-2}\). Azabora[9]helicenes consisting of angularly and linearly fused rings are blue emitters exhibiting Φ\(_{fl}\) of up to 47 % in CH\(_{2}\)Cl\(_{2}\) and 25 % in the solid state. As revealed by the DFT calculations, their P–M interconversion pathway is more complex than that of H1. Single‐crystal X‐ray analysis shows clear differences in the packing arrangement of methyl and phenyl derivatives. These molecules are proposed as primary structures of extended helices.
KW  - chirality
KW  - circular dichroism
KW  - fluorescence
KW  - helicene
KW  - organoboron
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225775
VL  - 60
IS  - 8
SP  - 4350
EP  - 4357
ER  - 
TY  - JOUR
A1  - Götz, Ralph
A1  - Kunz, Tobias C.
A1  - Fink, Julian
A1  - Solger, Franziska
A1  - Schlegel, Jan
A1  - Seibel, Jürgen
A1  - Kozjak-Pavlovic, Vera
A1  - Rudel, Thomas
A1  - Sauer, Markus
T1  - Nanoscale imaging of bacterial infections by sphingolipid expansion microscopy
JF  - Nature Communications
N2  - Expansion microscopy (ExM) enables super-resolution imaging of proteins and nucleic acids on conventional microscopes. However, imaging of details of the organization of lipid bilayers by light microscopy remains challenging. We introduce an unnatural short-chain azide- and amino-modified sphingolipid ceramide, which upon incorporation into membranes can be labeled by click chemistry and linked into hydrogels, followed by 4x to 10x expansion. Confocal and structured illumination microscopy (SIM) enable imaging of sphingolipids and their interactions with proteins in the plasma membrane and membrane of intracellular organelles with a spatial resolution of 10-20nm. As our functionalized sphingolipids accumulate efficiently in pathogens, we use sphingolipid ExM to investigate bacterial infections of human HeLa229 cells by Neisseria gonorrhoeae, Chlamydia trachomatis and Simkania negevensis with a resolution so far only provided by electron microscopy. In particular, sphingolipid ExM allows us to visualize the inner and outer membrane of intracellular bacteria and determine their distance to 27.6 +/- 7.7nm. Imaging of lipid bilayers using light microscopy is challenging. Here the authors label cells using a short chain click-compatible ceramide to visualize mammalian and bacterial membranes with expansion microscopy.
KW  - nanoscale imaging
KW  - bacterial infection
KW  - sphingolipid expansion microscopy
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231248
VL  - 11
ER  -