National Repository of Grey Literature 43 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Modification of Metal Surfaces by Optically Active [7]Helicene Derivatives for Molecular Sensing.
Walaská, Hana ; Kalachyova, Y. ; Elashnikov, R. ; Storch, Jan ; Žádný, Jaroslav ; Lyutakov, O.
New derivatives of 9-(pyridylethynyl)[7]helicenes were firstly prepared and fully characterized in this study. Consequently, they were successfully separated to their (P)- and (M)-enantiomers using a preparative HPLC with chiral stationary phase. These optical antipodes were advantageously used for modification of silver plasmon active nanogratings suitable for a SERS-based detection of (bio)molecules. Properties of such nanostructures were studied using different spectro- and microscopic techniques. As proved by UV-Vis spectrometry, a change of plasmon resonance wavelength position and intensity was observed and indicated the appearance of chiral surface plasmon polarization.
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Photochemical Derivatization of Helicenes.
Jakubec, Martin ; Ghosh, I. ; Storch, Jan ; König, B.
This work is focused on the use of simple helicene derivatives as substrates for modern photochemical methods. Halogen containing substrates are transformed in the reductive pathway to helicenyl radicals, before being trapped by different radical traps. In the oxidative pathway, activated alkoxyhelicenes undergo photoredox catalyzed reactions, yielding various carbon-carbon, as well as carbon-heteroatom containing compounds.\n
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Synthesis and Functionalization of Phenacenes Containing δ-Lactam Ring.
Váňa, Lubomír ; Církva, Vladimír ; Pfleger, Jiří ; Storch, Jan
This work is aimed at the development of a new efficient methodology towards the synthesis of various aza[5]phenacenes containing δ-lactam ring in their structure. Possibilities of their functionalization or derivatization are also discussed, along with complexation properties of suitable aza-derivatives as ligands in transition-metal complexes. The resulting compounds are investigated in terms of their material properties, especially for the formation of thin film structures capable of an efficient semi-conductivity or their potential application as photoluminescent complexes in OLEDs.
Synthesis of Steroid Derivatives for In Vitro Diagnostics.
Kos, Martin ; Váňa, Lubomír ; Žádný, Jaroslav ; Storch, Jan
This work is focused on the synthesis of novel steroidal androgen derivatives consisting of a steroidal skeleton, a spacer and imidazole ring or a primary amine functional group. The starting material for the synthesis is represented by commercial available hydroxy-androgens, which are further modified. First, the hydroxyl group is attached to the spacer and then connected to the desired imidazole or the protected primary amine. The above described derivatives will be utilized for development of analytical kits for a determination of the free steroid hormone.
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Preparation and Physicochemical Properties of [6]Helicenes Fluorinated at Terminal Rings.
Církva, Vladimír ; Jakubík, Pavel ; Žádný, Jaroslav ; Vacek, J. ; Strašák, Tomáš ; Hrbáč, J. ; Císařová, I. ; Storch, Jan
Two fluorinated helicenes, tetrafluoro[6]helicene and octafluoro[6]helicene were prepared photochemically and their physicochemical and optical properties were investigated. A separation of racemic tetrafluoro[6]helicene into individual enantiomers (P and M) was performed and the racemization barrier was determined. Crystal structures of major synthetic products including individual enantiomers of tetrafluoro[6]helicene were determined showing the replacement of π-π and CH-π interactions by CH-F interactions with increasing fluorine substitution. DFT calculation were performed to get an insight into the charge distribution and HOMO-LUMO gap.
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