Ahmet Orhan Görgülü

Coumarin Based Highly Selective “off-on-off” Type Novel Fluorescent Sensor for Cu 2+ and S 2− in Aqueous Solution

AbstractSolvent free synthesis of 6,7-dihydroxy-3-(3-chlorophenyl) coumarin (CFHC) was designed and obtained by the interaction of 2-(2,4,5-trimethoxyphenyl)-1-(3-chlorophenyl)acrylonitrile with pyridinium hydrochloride in the presence of silica gel by using microwave irradiation. The characterization of CFHC was confirmed by FT-IR, 1H, 13C, 13C–APT and 2D HETCOR spectroscopy methods. The optical behavior of CFHC towards metal ions was investigated by UV-visible and fluorescence spectroscopy. CFHC showed “on–off” type fluorescence response towards Cu2+ with high selectivity in aqueous solution (CH3CN/H2O, 9/1, v/v). Once binding with Cu2+, CFHC-Cu2+ complex also displayed high selectivity for sulfide, resulting in “off–on” type sensing of sulfide anion. Graphical abstractVisual fluorescence changes upon addition of various metal ions (5.0 eq.) to CFHC in CH3CN/H2O (90:10, v/v) under UV excitation (365 nm)

Synthesis, Characterization, and Biological–Pharmacological Evaluation of New Phosphazenes Bearing Dioxybiphenyl and Schiff Base Groups

A new spirocyclophosphazene, 2,2‐bis(2‐formylphenoxy)‐4,4,6,6‐bis[spiro(2′,2″‐dioxy‐1′‐1″‐biphenylyl)]cyclotriphosphazene (3), was obtained from the reaction of 2,2‐dichloro‐4,4,6,6‐bis[spiro(2′,2″‐dioxy‐1′‐1″‐biphenylyl)]cyclotriphosphazene (2) with 2‐hydroxybenzaldehyde. New phosphazene derivatives bearing Schiff base and dioxybiphenyl groups have been synthesized by the reactions of 3 with different amines. The structures of the compounds were defined by elemental analysis, IR, 1H, 13C, and 31P NMR spectroscopy. All the synthesized compounds were screened for their antibacterial activity against both types of Gram‐negative and Gram‐positive bacteria. The most potent antibacterial compound of this series was compound 12 which has the low MIC value of 3.75–0.9375 µg/mL. Both minimal inhibitory concentrations (MIC) and inhibition zones were determined in order to monitor the efficacy of the synthesized compounds. New compounds were also screened for anticonvulsant, CNS depressant, and sedative‐hypnotic activity. After i.p. injection to mice at doses of 30, 100, and 300 mg/kg body weight phosphazenes were examined in the maximal electroshock‐induced seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) induced seizure models in mice. The neurotoxicity was assessed using the rotorod method. Compounds 4, 5, and 11 were found to be active in both MES screen and scPTZ screen at 0.5 h. All except 12 showed more than 44% decrease in locomotor activity after 1 h of compound administration via actophotometer screen. CNS‐depressant activity screened with the help of the forced swim method resulted in some potent compounds. Except for 7 and 12 other tested compounds were found to exhibit potent CNS depressants activity as indicated by increased immobility time.

SYNTHESIS AND CHARACTERIZATION OF TWO 2-AMINO-5-ALKYL-1,3,4-THIADIAZOLYL CARBAMATE LIGANDS AND THEIR Co(II), Ni(II), AND Zn(II) COMPLEXES

ABSTRACT Two novel monodentate carbamate ligands derived from 2-amino-5-methyl-1,3,4-thiadiazole and 2-amino-5-ethyl-1,3,4-thiadiazole, have been prepared. The metal complexes of the ligands were prepared with the chlorides of Co(II), Ni(II) and Zn(II) in methanol as solvent. The ligands and their metal complexes have been characterized by elemental analyses, IR, 13C and 1H NMR spectra, and magnetic susceptibility measurements. All of the complexes are mononuclear. Thermal properties of the ligands and their complexes have been studied by thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC).

A kinetic study of mercury(II) transport through a membrane assisted by new transport reagent

BackgroundA new organodithiophosphorus derivative, namely O-(1,3-Bispiperidino-2-propyl)-4-methoxy phenyldithiophosphonate, was synthesized and then the kinetic behavior of the transport process as a function of concentration, temperature, stirring rate and solvents was investigated.ResultsThe compound 1 was characterized by elemental analysis, IR, 1H and 31P NMR spectroscopies. The transport of mercury(II) ion by a zwitterionic dithiophosphonate 1 in the liquid membrane was studied and the kinetic behavior of the transport process as a function of concentration, temperature, stirring rate and solvents was investigated. The compound 1 is expected to serve as a model liquid membrane transport with mercury(II) ions.ConclusionA kinetic study of mercury(II) transport through a membrane assisted by O-(1,3-Bispiperidino-2-propyl)-4-methoxy phenyldithiophosphonate was performed. It can be concluded that the compound 1 can be provided a general and straightforward route to remove toxic metals ions such as mercury(II) ion from water or other solution.

Synthesis and characterization of a new pyrrolidine containing sulfur ligand and the transition metal complexes of Co(II), Ni(II) and Cu(I)

Potassium 1,3-dipyrrolidinopropan-2-O-xanthate (LK), and its complexes with Co(II), Ni(II) and Cu(I) have been prepared and characterized as [CoL2(H2O)2] · 2H2O, [NiL2(H2O)2] and CuL · 2H2O by FT-IR, 1H and 13C NMR spectroscopies, elemental analyses, magnetic susceptibility and TGA techniques.

Structural, electrical and photoresponse properties of si-based diode with organic interfacial layer containing novel cyclotriphosphazene compound

The electrical and photoresponse properties of Al/p-Si/organic layer/Al diode were investigated. Organic layer containing novel 2,2-bis[spiro(7,8-dioxy- 4-methylcoumarin)]-4,4,6,6-bis[spiro(2’,2”-dioxy-1’,1”- biphenylyl)]cyclotriphosphazene compound was coated by drop casting method on p-Si having ohmic contact. The structural characterization of novel cyclotriphosphazene compound was confirmed by using 1H, 13C and 31P-NMR, elemental analysis and FT-IR spectroscopic techniques. The diode exhibits a photoconducting and photodiode behavior under solar light illumination. The electrical parameters such as ideality factor, barrier height and series resistance of the diode were determined from I-V characteristics. It is seen that the photocurrent of the diode under illumination is higher than dark current. Also, the frequency dependence of capacitance (C) and conductance (G) was explained on the basis of interface states. It is evaluated that the hybrid photodiode can be used as a photosensor in organic photodetector applications.

Synthesis, structural and thermal characterizations and in vitro cytotoxic activities of new cyclotriphosphazene derivatives

GRAPHICAL ABSTRACT ABSTRACT We investigated the cytotoxic effects of the newly synthesized cyclotriphosphazene derivatives on A2780 (ovarian), PC-3 and LNCaP (prostate) cancer cell lines. 4′-hydroxy-substituted-chalcone compounds (2–8) were reacted with diphenyl-cyclotriphosphazene (DPP) in the presence of acetone/K2CO3 in order to obtain novel cyclotriphosphazene compounds (DPP 2–8). The structures of DPP 2–8 were characterized by MALDI-TOF mass spectrometry, FT-IR, elemental analysis, 1H, 13C-APT, and 31P NMR measurements. The thermal properties of all phosphazene compounds have been studied after synthesis and characterization procedure. The cytotoxic effects of DPP 2–8 were examined primarily by applying the MTT method based on the measurement of mitochondrial activity. In this regard, several phosphazene compounds have shown high chemotherapeutic effect at low dose (p < 0.05). When the cytotoxic effects of DPP 2–8 at doses of 1, 5, 25, 50 and 100 µM on A2780 cells were examined, it was observed that DPP-3, DPP-4, DPP-5 and DPP-7 were more effective than other derivatives suggested by their high Log IC50 values (p < 0.05). The compounds DPP 2–8 possess cytotoxic activity against PC-3 and LNCaP cells (especially compounds DPP-4 and DPP-5, p < 0.05).

Synthesis, structural and thermal characterizations, dielectric properties and in vitro cytotoxic activities of new 2,2,4,4-tetra(4′- oxy-substituted-chalcone)-6,6-diphenylcyclotriphosphazene derivatives

In this study, we aimed to investigate the relationship between the cytotoxic and dielectric properties of newly synthesized 2,2,4,4-tetra(4′-oxy-substituted-chalcone)-6,6-diphenylcyclotriphosphazene derivatives (3–10). Firstly, 2,2,4,4-tetrachloro-6,6-diphenyl cyclotriphosphazene (2) was obtained through Friedel Crafts alkylation in the presence of hexachlorocyclotriphosphazene, benzene and triethylamine and anhydrous AlCl3. The compounds 3–10 were synthesized from the reaction of the hydroxychalcone compounds (1a–h) with 2 in the presence of K2CO3 and within the acetone solvent for the first time and their dielectric constant, dielectric loss factor and ac conductivity of compounds 3–10 were examined through the impedance analyzer as a function of frequency. The in vitro cytotoxic activities of compounds 3–10 in five different concentrations (1, 5, 25, 50, and 100 µM) were analyzed by colorimetric MTT assay which is based on reduction of MTT salt by mitochondria of alive cells over the human ovarian cancer (A2780) and human prostate cancer (PC-3 and LNCaP) cell lines. The LogIC50 values of 3–10 were calculated by using a Graphpad prism 6 programs on a computer. The obtained results suggests that the compounds have a powerful cytotoxic activity (especially A2780, p < 0.05).

4-(Furan-2-ylmeth-oxy)benzene-1,2-dicarbonitrile.

In the title compound, C13H8N2O2, prepared from furfuryl alcohol and 4-nitrophthalonitrile in the presence of potassium carbonate in dimethylformamide, the furan and benzene rings are oriented at a dihedral angle of 53.45 (9)°. In the crystal, weak C—H⋯O and C—H⋯N hydrogen bonds link the molecules into a three-dimensional network.

Selective and sensitive fluorescent and colorimetric chemosensor for detection of CO 3 2- anions in aqueous solution and living cells

A new colorimetric and fluorescent chemosensor for visual determination of carbonate ions was developed by the microwave assisted solvent free synthesis of 7,8-dihydroxy-3-(4-methylphenyl) coumarin (DHMC). The structural characterization of DHMC was confirmed by microanalysis and spectroscopy methods (MALDI-TOF, FT-IR, 1H NMR, 13C NMR, and 2D HETCOR). The binding behaviors of DHMC were investigated towards various anions by UV-vis and fluorescence spectroscopy. DHMC showed a selective and sensitive fluorometric and colorimetric responses towards carbonate ion over other anions. The detection limit of CO32- was found to be 1.03 µM. Moreover, the fluorescence imaging in living cells suggests that DHMC has a great potential in the biological imaging application. It has been demonstrated that DHMC can be used as a rapid and reliable sensor for the determination of carbonate anion in a variety of practical applications.