5 research outputs found
Oxidation and reduction processes for 1,10-phenanthroline derivatives and their analogs
Rozprawa doktorska podzielona jest na trzy cz臋艣ci: wst臋p teoretyczny, badania w艂asne oraz cz臋艣膰 eksperymentaln膮. Wst臋p teoretyczny podzielony jest na poszczeg贸lne rozdzia艂y, w kt贸rych opisano: otrzymywanie, zastosowanie i funkcjonalizacje pochodnych 1,10-fenantroliny, chinoliny oraz w艂a艣ciwo艣ci elektrochemiczne wybranych N-heterocykli. W badaniach w艂asnych opisano syntezy wybranych symetrycznych i niesymetrycznych pochodnych 1,10-fenantroliny oraz ich funkcjonalizacj臋 a tak偶e reakcje utleniania i hydrolizy ww. zwi膮zk贸w. Poza tym przedstawiono badania elektrochemiczne, w kt贸rych zaproponowano mechanizmy utlenienia i redukcji badanych zwi膮zk贸w. Dodatkowo przedstawiono syntezy i funkcjonalizacje pochodnych chinoliny i benzo[h]chinoliny oraz reakcje VNS dla wybranych pochodnych nitrochinoliny. Cz臋艣膰 eksperymentalna zawiera procedury otrzymywania zwi膮zk贸w, analiz臋 spektraln膮 produkt贸w oraz spis instrument贸w, z kt贸rych korzystano podczas realizacji tej pracy
Synthesis and Electrochemical and Spectroscopic Characterization of 4,7-diamino- 1,10-phenanthrolines and Their Precursors
New approaches to the synthesis of 4,7-dichloro-1,10-phenanthrolines and their
corresponding 9H-carbazol-9-yl-, 10H-phenothiazin-10-yl- and pyrrolidin-1-yl derivatives were
developed. Their properties have been characterized by a combination of several techniques: MS,
HRMS, GC-MS, electronic absorption spectroscopy and multinuclear NMR in both solution and
solid state including 15N CP/MAS NMR. The structures of 5-fluoro-2,9-dimethyl-4,7-di(pyrrolidin-
1-yl)-1,10-phenanthroline (5d), 4,7-di(9H-carbazol-9-yl)-9-oxo-9,10-dihydro-1,10-phenanthroline-5-
carbonitrile (6a) and 4,7-di(10H-phenothiazin-10-yl)-1,10-phenanthroline-5-carbonitrile (6b) were
determined by single-crystal X-ray diffraction measurements. The nucleophilic substitutions of
hydrogen followed by oxidation produced compounds 6a and 6b. The electrochemical properties
of selected 1,10-phenanthrolines were investigated using cyclic voltammetry and compared with
commercially available reference 1,10-phenanthrolin-5-amine (5l). The spatial distribution of
frontier molecular orbitals of the selected compounds has been calculated by density functional
theory (DFT). It was shown that potentials of reduction and oxidation were in consistence with the
level of HOMO and LUMO energies
Synthesis, electrochemical and spectroscopic characterization of selected quinolinecarbaldehydes and their Schiff base derivatives
A new approach to the synthesis of selected quinolinecarbaldehydes with carbonyl groups located at C5 and/or in C7 positions is presented in this paper in conjunction with spectroscopic characterization of the products. The classical Reimer-Tiemann, Vilsmeier-Haack and Duff aldehyde synthesis methods were compared due to their importance. Computational studies were carried out to explain the preferred selectivity of the presented formylation transformations. A carbene insertion reaction based on Reimer-Tiemann methodology is presented for making 7-bromo-8-hydroxyquinoline-5-carbaldehyde. Additionally, Duff and Vilsmeier-Haack reactions were used in the double formylation of quinoline derivatives and their analogues benzo[h]quinolin-10-ol, 8-hydroxy-2-methylquinoline-5,7-dicarbaldehyde, 8-(dimethylamino) quinoline-5,7-dicarbaldehyde and 10-hydroxybenzo[h]quinoline-7,9-dicarbaldehyde. Four Schiff base derivatives of 2,6-diisopropylbenzenamine were prepared from selected quinoline-5-carbaldehydes and quinoline-7-carbaldehyde by an efficient synthesis protocol. Their properties have been characterized by a combination of several techniques: MS, HRMS, GC-MS, FTIR, electronic absorption spectroscopy and multinuclear NMR. The electrochemical properties of 8-hydroxy-quinoline-5-carbaldehyde, 6-(dimethylamino)quinoline-5-carbaldehyde and its methylated derivative were investigated, and a strong correlation between the chemical structure and obtained reduction and oxidation potentials was found. The presence of a methyl group facilitates oxidation. In contrast, the reduction potential of methylated compounds was more negative comparing to non-methylated structure. Calculations of frontier molecular orbitals supported the finding. The structures of 8-hydroxy-2-methylquinoline-5,7-dicarbaldehyde and four Schiff bases were determined by single-crystal X-ray diffraction measurements
Spectroelectrochemical properties of 1,10- phenanthroline substituted by phenothiazine and carbazole redox-active units
Complexes of 1,10-phenanthrolines with cations of transition metals have broad range of applications. This work aims at designing and investigating phenothiazine and carbazole substituted 1,10-phenanthrolines as ligands for future complexes with transient metal cations. The combined electrochemical, spectroelectrochemical and DFT studies were employed to demonstrate the effect of broken symmetry in substituted 4,7-di(phenothiazine)-1,10-phenanthrolines on their spectroelectrochemical properties. A reversible color change (new absorption band around 500 nm) due to phenothiazine radical cation was observed in the first oxidation step. Results further indicate that phenothiazine substituents behave as two equivalent but almost electronically isolated redox centres. The work additionally presents a comprehensive reaction mechanistic study of oxidation and reduction processes complemented by HPLC-MS/MS identification
Direct amination of nitroquinoline derivatives via nucleophilic displacement of aromatic hydrogen
The vicarious nucleophilic substitution of hydrogen (VNS) reaction in electron-deficient nitroquinolines was studied. Properties of all new products have been characterized by several techniques: MS, HRMS, FTIR, GC-MS, electronic absorption spectroscopy, and multinuclear NMR. The structures of 4-chloro-8-nitroquinoline, 8-(tert-butyl)-2-methyl-5-nitroquinoline, 9-(8-nitroquinolin-7-yl)-9H-carbazole and (Z)-7-(9H-carbazol-9-yl)-8-(hydroxyimino)quinolin-5(8H)-one were determined by single-crystal X-ray diffraction measurements. The 9-(8-nitroquinolin-7-yl)-9H-carbazole and (Z)-7-(9H-carbazol-9-yl)-8-(hydroxyimino)quinolin-5(8H)-one illustrate the nitro/nitroso conversion within VNS reaction. Additionally, 9-(8-isopropyl-2-((8-isopropyl-2-methyl-5-nitroquinolin-6-yl)methyl)-5-nitrosoquinolin-6-yl)-9H-carbazole is presented as a double VNS product. It is postulated that the potassium counterion interacts with the oxygen on the nitro group, which could influence nucleophile attack in that way