National Repository of Grey Literature 5 records found  Search took 0.00 seconds. 
Application of In situ TR Spectroelectrochemical Techniques in Determination of Redox Mechanism of Bioactive Compounds
Sokolová, Romana ; Jiroušková, Eliška ; Degano, I. ; Wantulok, J. ; Nycz, J.
The electron transfer reactions play an important role in many natural processes. Reactions such as \ndissociation, protonation, and reactions with water and other small molecules often occur in \nbiotransformation. The reaction schemes involving these chemical reactions coupled to the \nelectron transfer can be determined by cyclic voltammetry. Additionally, in \nsitu spectroelectrochemistry can efficiently contribute to the determination of oxidation or \nreduction mechanism. This technique provides information about the electroactive chromophore during \nthe redox process allowing to identification the first reaction intermediates. The final reaction \nproducts were identified by chromatographic techniques. This study represents a key role of TR \nspectroelectrochemistry in the determination of reaction intermediates in the case of \n1,10- phenanthroline derivative substituted by bioactive phenothiazine unit and \ndrug 3- fluorophenmetrazine (2-(3-fluorophenyl)-3-methylmorpholine, 3-FPM). Co pound 3-FPM\nhave recently appeared as the new psychoactive substance in the drug market.\n
Spectroelectrochemistry of 1,10-phenantrolines Substituted by Pyrrolidine and Phenothiazine Redox-active Units
Sokolová, Romana ; Wantulok, J. ; Fiedler, Jan ; Nycz, J. ; Degano, I.
Compounds based on 1,10-phenanthroline (Phen) and their complexes are used in many fields, such as a stabilizing agent in the synthesis of nanoparticles, catalysts in homogeneous catalysis and as a semiconductor in organic light-emitting diodes (OLED) due to their coordination abilities. In this work, 1,10-phenanthrolines functionalized by pyrrolidine and phenothiazine units were studied by electrochemical methods. Cyclic voltammetry resulted in several oxidation and reduction voltammetric peaks. Structure-activity relationship was investigated using in situ spectroeletrochemistry, spectrophotometry, infrared spectroscopy and chromatography.
UV-Vis and IR Spectroelectrocbemistry of Copper Complexes and Bioactive Compounds
Sokolová, Romana ; Obluková, Michaela ; Sýs, M. ; Mikysek, T. ; Wantulok, J. ; Nycz, J. E. ; Degano, I.
The interpretation of the change of absorption spectrum of an oxidized and reduced molecule\nrecorded during the electron transfer is an efficient tool for the determination of oxidation or\nreduction mechanism. This technique provides the information about the electroactive\nchromophore and is performed in two regimes of electrochemical measurement, cyclic\nvoltammetry and chronoamperometry, respectively. This approach was successfully applied to\nstudy the fundamental electrochemical behavior of recently synthesized copper complexes\nproviding biomimetic activity, ofpolyphenolic bioactive compounds, and also for the reduction\nof halogenated phenanthrolines. The identification of redox products was done by\nchromatographic techniques as HPLC-DAD and HPLC-ESI-MS/MS.
Oxidation and Reduction of Selected 1,10-Phenantrolines
Wantulok, J. ; Sokolová, Romana ; Nycz, J. E. ; Degano, I.
Derivatives of 1,10-phenanthroline (Phen) are well-known bident ligands which had a lot of interesting applications thanks to their coordination abilities. Selected 1,10-phenanthroline compounds were studied by electrochemical methods. Depending on their different substituents were observed several oxidation and reduction voltammetric peaks. The study involves also in situ spectroeletrochemistry, infrared spectroscopy and identification of products by HPLC-DAD and HPLC-ESI MS/MS.
Reduction and Oxidation of Hydroxyquinolines in Acetonitrile and Dimethylsulfoxide
Sokolová, Romana ; Ramešová, Šárka ; Fiedler, Jan ; Kolivoška, Viliam ; Degano, I. ; Gál, M. ; Szala, M. ; Nycz, J. E.
This study is focused on investigation of oxidation and reduction pathways of selected hydroxyquinoline compounds in nonaqueous solutions. The experimentally obtained reduction potentials are reported to well correlate with calculated values of LUMO energies as well as the obtained oxidation potentials are in a good agreement with theoretical HOMO energies. The cyclic voltammetry, in situ UV/Vis spectroelectrochemistry and in situ IR spectroelectrochemistry confirmed that the oxidation mechanism is complicated. Oxidation unexpectedly proceeds together with protonation of the starting compound. This behaviour was found for all studied compounds, hydroxyquinoline carboxylic acids and also for compounds, where a methyl group is present instead of carboxylic group.