Novel 1,4-naphthoquinone N-aroylthioureas: Syntheses, crystal structure, anion recognition properties, DFT studies and determination of acid dissociation constants
Gemili, Müge | Nural, Yahya
In this paper, five novel 1,4-naphthoquinone N-aroylthiourea derivatives were synthesized, by the reaction of 2,3-diaminonaphthalene-1,4-dione and aroylisothiocyanates, in excellent yield (88-96%) and characterized by using FT-IR, H-1/C-13 NMR and HRMS. In addition, the molecular structure of one of the 1,4-naphthoquinone N-aroylthiourea compounds was characterized by single crystal X-ray diffraction studies. The absorption spectra of the compounds were determined in DMSO and the dyes have absorption in visible region in the range of 464-477 nm. The chemosensing ability of each of the prepared dyes was assessed by titrating them towards the anions; F-, Cl-, Br-, I- AcO-, CN-, CIO4-, H2PO4-, HSO4-, and NO3-, using spectrophotometric and H-1 NMR titration techniques in DMSO, experimentally. ...
New naphthoquinone-imidazole hybrids: Synthesis, anion recognition properties, DFT studies and acid dissociation constants
Nural Yahya
The two new naphthoquinone-imidazole based dyes containing indole and pyrene moiety were synthesized and their molecular structures were confirmed by FT-IR, H-1/C-13 NMR, and HRMS. The anion selectivity and sensitivity of dyes were studied with selected TBA salts in DMSO and binary mixture DMSO:Water (1:1, v/v). These interaction mechanisms were verified by spectrophotometric, spectrofluorometric, and H-1 NMR titration methods. While the both dyes interact with F-, AcO-, CN-, and H2PO4- in DMSO, only CN- interact with dyes in the aqueous solution. In addition, the experimental results were explained by DFT calculations. The acid dissociation constants of the dyes were determined in 25.0 +/- 0.1 degrees C, 0.1 M NaCl ionic strength in 40% (v/v) DMSO-Water aqueous solution, and acid dissocia...
Novel fluorescent sensors based on coumarin-hydrazide-hydrazone hybrid for the detection of CN-, Co2+ and Ni2+ ions: DFT and bioimaging in living cells
Nural, Yahya
Novel coumarin-hydrazide-hydrazone hybrids, (E)-7-(diethylamino)-N '-(2-hydroxy-3-methoxybenzylidene)-2oxo-2H-chromene-3-carbohydrazide (1) and (E)-7-(diethylamino)-N '-(4-(diethylamino)-2-hydroxybenzylidene)2-oxo-2H-chromene-3-carbohydrazide (2), were synthesized and investigated their chemosensor properties. The sensors showed recognition properties of CN-, Co2+, and Ni2+ ions. After interaction with the cyanide anion, the coumarin-hydrazide-hydrazone sensors exhibited a color change visible to the naked eye, from yellow to colorless under daylight and from blue to green under UV light. The sensors exhibited a significant fluorescent enhancement response to the cyanide anion by the intramolecular charge transfer (ICT) mechanism. Furthermore, the recognition of cations was obser...