Ozcan Kocyigit

Anthracene excimer-based “turn on” fluorescent sensor for Cr3+ and Fe3+ ions: Its application to living cells

A novel anthracene based fluorescent probe containing benzothiazole group (BFA) was designed and synthesized. The cation binding properties of BFA were studied in the presence of various cations. Both UV-vis and fluorescence spectroscopic studies indicated that BFA was highly sensitive and selective toward trivalent cations (Cr(3+) and Fe(3+)), while there was no response to monovalent, divalent cations and also Al(3+) ion. The interaction of BFA with Cr(3+) and Fe(3+) caused a significant enhancement in emission intensity due to the combination of a unique anthracenyl static excimer formation, the restricted C=N isomerization and the suppression of highly efficient photoinduced electron transfer (PET) process. The detection limits of BFA for Cr(3+) and Fe(3+) were 0.46 and 0.45µM, which presented a pronounced sensitivity toward Cr(3+) and Fe(3+), respectively. Also, possible utilization of BFA as bio-imaging fluorescent probe to detect Cr(3+) and Fe(3+) in human prostate cancer cell lines was observed by confocal fluorescence microscopy.

Complexation properties and synthesis of a novel Schiff base with triphenylene nucleus

We presented the synthesis of a novel Schiff base and its complexation properties with some transition metal ions in this work. For this, the 2,3,4,6,7,10,11 hexahydroxytriphenylene (HHTP) as starting material was synthesized according to known procedure. Moreover, the 2-((2-chloroethylimino)methyl) phenol material was prepared with reaction of salicylaldehyde and 2-chloroethylamine hydrochloride. To give the 2,3,4,6,7,10,11-hexakis(salicyliminoethoxy)triphenylene (HSE-TP) as a novel Schiff base, the HHTP were treated with 2-((2-chloroethylimino)methyl)phenol in acetone media. Complexation properties of this Schiff base were investigated towards Ni(II), Cu(II), Co(II), Zn(II), Pd(II) and Cd(II) as transition metals. The structures of these new compounds (ligand and complexes) were characterized with FT-IR, magnetic susceptibility measurement, thermal methods (TGA), (1)H NMR and elemental analyses.

A novel colorimetric and fluorescent sensor based on calix[4]arene possessing triphenylamine units.

A novel colorimetric and fluorometric calix[4]arene probe (CTP) bearing triphenylamine units was synthesized in good yield and characterized by combination of (1)H, (13)C, APT, COSY, FTIR, HRMS, and UV-vis spectral data. Ion-binding studies of CTP were investigated in acetonitrile with a wide range of cations and anions and the recognition process was monitored by luminescence, UV-vis and (1)H NMR spectral changes. CTP exhibited naked eye detection for Hg(2+) ion. Also it showed a significant fluorescence quenching towards F(-) ion.

Excess molar volumes, viscosity, refractive index, and Gibbs energy of activation of binary biodiesel + benzene, and biodiesel + toluene mixtures at 298.15 and 303.15 K

Excess molar volumes (VE), viscosities, refractive index, and Gibbs energies were evaluated for binary biodiesel + benzene and toluene mixtures at 298.15 and 303.15 K. The excess molar volumes VE were determined from density, while the excess Gibbs free energy of activation G*E was calculated from viscosity deviation Δη. The excess molar volume (VE), viscosity deviation (Δη), and excess Gibbs energy of activation (G*E) were fitted to the Redlich-Kister polynomial equation to derive binary coefficients and estimate the standard deviations between the experimental data and calculation results. All mixtures showed positive VE values obviously caused by increased physical interactions between biodiesel and the organic solvents.

Fluorogenic Recognition of Zn 2+ , Al 3+ and F − Ions by a New Multi-Analyte Chemosensor Based Bisphenol A-Quinoline

A new available multi-analyte fluorescent sensor based on a bisphenol A-quinoline conjugate (BFQ) was synthesized in two facile steps and was characterized systematically. BFQ exhibited an effectively selective and sensitive recognition toward Zn2+and Al3+ cations in EtOH-H2O (v/v = 9/1) over other cations and F− anion in CH3CN over other anions with remarkably enhanced fluorescent intensities. According to the quantum yield (Φ) measurements, BFQ-Zn2+, BFQ-Al3+ and BFQ-F− complexes showed 16, 22 and 30 times higher Φ values than BFQ, respectively. The complexation properties of BFQ with Zn2+, Al3+ and F− ions were also examined by 1H NMR titration experiments.

Properties and Synthesis of the Cr(III)-Salen/Salophen Complexes Containing Triphenylamine Core

Two triphenylamine derivatives bearing 4-aminobenzoic acid and 5-aminoisophthalic acid were synthesized. Then, the prepared triphenylamine derivatives were reacted with two new Cr(III) complexes involving tetradenta Schiff bases N,N-bis(salicylidene)ethylenediamine or bis(salicylidene)-o-phenylenediamine. The structures of these compounds were characterized by elemental analysis, FT-IR, TG, 1H NMR, and 13C NMR techniques and magnetic susceptibility measurement. The complexes can also be characterized as low-spin distorted octahedral Cr(III) bridged by carboxylic acids. The carboxylic acids play a role as bridges for weak antiferromagnetic intramolecular exchange. Also, the UV spectra of these derivatives revealed that the maximum wavelengths of the complexes are shifted, compared with the ligands.