Furkan Özen

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.

Type I plasminogen activator inhibitor 4G allele frequency is associated with chronic venous insufficiency.

Chronic venous insufficiency (CVI) is a common disease associated with poor quality of life. Genetic polymorphisms causing coagulation abnormalities may account for some of the CVI pathogenesis. Type I plasminogen activator inhibitor (PAI-1) is responsible for fibrinolytic system regulation, and plasma levels of PAI-1 are strongly correlated with PAI-1 4G/5G gene polymorphism. The association between PAI-1 4G/5G gene polymorphism and CVI was investigated. In 34 consecutive patients with clinically overt CVI, the PAI-1 4G/4G polymorphism was detected in three cases (8.8%); the 4G/5G polymorphism was detected in 28 (82.4%). In 34 age- and sex-matched controls, the PAI-1 4G/4G polymorphism was detected in one case (2.9%) and the 4G/5G polymorphism was detected in 14 cases (41.2%). The PAI-1 4G allele was found significantly more frequently in CVI patients than in controls. The 4G allele was associated with a 3.25-fold increase in CVI risk. Thus, a relationship between CVI and the PAI-1 4G allele is apparent.

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.

Erratum to: Synthesis, characterization, and biological evaluation of new oxime-phosphazenes

Erratum to: Res Chem Intermed (2013) 39:1109–1124DOI 10.1007/s11164-012-0670-2We have discerned that, in our work, one of the authors made mistakes in thebiological result tables (Tables 1, 2). Because discussions and conclusions weremade by evaluation of data that was presented in these tables, the discussions andconclusions, abstract, and sections of the article also contain mistakes. We apologiseto the Publisher, scientific world, Editorial Board of Research on ChemicalI˙ntermediates, and all readers for these great mistakes. The tables, and the relatedparts of abstract, discussions and conclusions sections of the article are corrected inthis erratum.Tables 1 and 2 are corrected as below: