National Repository of Grey Literature 50 records found  previous11 - 20nextend  jump to record: Search took 0.00 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.
Fulltext: content.csg - Download fulltextPDF
Plný tet: SKMBT_C22018110615053 - Download fulltextPDF
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
Fulltext: content.csg - Download fulltextPDF
Plný tet: SKMBT_C22018110615051 - Download fulltextPDF
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.
Fulltext: Download fulltextPDF
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.
Fulltext: content.csg - Download fulltextPDF
Plný tet: SKMBT_C22018110615054 - Download fulltextPDF
Understanding the Principles of Diastereomeric Complexes of Chiral Urea Derivatives.
Cuřínová, Petra ; Jakubec, Martin ; Storch, Jan ; Holakovský, R.
The main target of this work based on the NMR studies is to elucidate the structural principles which are responsible for the action of the chiral selectors at hand, and thus to be able to predict the new promising structures useful as NMR shift reagents.
Fulltext: Download fulltextPDF
Chiral Carbon-rich Materials – From Single Molecule to Functional Layers.
Žádný, Jaroslav ; Storch, Jan ; Strašák, Tomáš ; Krbal, M. ; Hrbáč, J. ; Vacek, J.
Comprehensive study of two different carbon-rich materials properties – [6]helicene and 1-butyl-3-(2-methyl[6]helicenyl)imidazolium bromide – and their thin films is presented. Because of different solubility, diverse preparation approaches had to be employed – electropolymerization and spin-coating. Spectroscopic and electrochemical properties were investigated along with examples of their practical use as detectors of biomolecules (e.g. DNAs). A high application potential of helicene-based carbon-rich materials in development of new optoelectronic devices is demonstrated.
Fulltext: Download fulltextPDF
Application of Cyclopentenediones for Preparation of Permselective Layers.
Vacek, J. ; Hrbáč, J. ; Matějka, P. ; Storch, Jan
In this contribution, we report that electrooxidation of PCD, phenolic cyclopentenedione, 2,2'-bis[4,5-bis(4-hydroxybenzyl)-2-(4-hydroxyphenyl)-cyclopent-4-ene-1,3-dione] results in the formation of stable films with permselective properties on metal and carbon surfaces. The electropolymerization process proceeds in neutral and alkaline aqueous medium at potentials higher than +0.6 V (vs. Ag/AgCl/3M KCl). The PCD polymer prepared was characterized by electrochemical methods, quartz crystal microbalance and optical spectroscopy techniques. The PCD film can be used for electrode coating and preparation of an anti-interference barrier. Thus, we performed SAR study which could open the door to developing novel functional films and electrochemical tools for bioactive compounds sensing.\n
Fulltext: content.csg - Download fulltextPDF
Plný tet: MEM20140001 - Download fulltextPDF

National Repository of Grey Literature : 50 records found   previous11 - 20nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.