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Öğe A Schiff base based on triphenylamine and thiophene moieties as a fluorescent sensor for Cr (III) ions: Synthesis, characterization and fluorescent applications(Elsevier Science Sa, 2020) Kolcu, Feyza; Erdener, Diğdem; Kaya, İsmetA Schiff base fluorescent sensor was designed for selective detection of Cr3+ ions in aqueous solution. The procedure for the study was fulfilled in three steps which comprised the synthesis of 4-nitro-triphenylamine (TPA-NO2), 4-amino-triphenylamine (TPA-NH2) and Schiff base (TPA-Th) using 2,2′-bithiophene-5-carboxaldehyde, respectively. Structural characterization of the purely synthesized compounds was acquired by using UV–Vis, FT-IR, 1H NMR and 13C NMR analyses. Their electrochemical, thermal, and the optical sensor properties for metal ions were enlightened by cyclic voltammetry (CV), thermal-TG-DTA and photoluminescence (PL) techniques, respectively. Non-fluorescent TPA-Th displayed a fluorescence enhancement after chelation with Cr3+ ions with high selectivity and overall emission change of 59-fold at an excitation wavelength of 320 nm. The limit of detection (LOD) value was as low as 1.5 × 10−6 M for Cr3+ ions, accompanied by an association constant (Ka) of 2.8 × 104 M−1. TPA-Th was beneficial for the design and development of metal-complexed fluorescent sensor and light emitting devices.Öğe Amino-functionalized nitrogen-doped graphene quantum dots and silver-graphene based nanocomposites: Ultrafast charge transfer and a proof-of-concept study for bioimaging applications(Elsevier B.V., 2022) Karatay, Ahmet; Erdener, Diğdem; Gürcan, Cansu; Yıldız, Elif Akhüseyin; Yılmazer, Açelya; Boyacıoğlu, Bahadır; Yıldız, MustafaRecent advances in nanotechnology have led to the use of graphene quantum dots (GQDs) for functional imaging and cancer therapy. Thanks to the physicochemical properties of graphene, GQDs have been functionalized and modified to improve their biological properties. In this study, polyethyleneimine functionalized nitrogen-doped graphene quantum dots (PEI N-doped GQDs) and silver nanoparticles/nitrogen-doped graphene quantum dots (AgNPs/PEI N-doped GQDs) nanocomposites have been developed. The PEI N-doped GQDs show a strong emission spectrum at maximum 446 nm with 356 nm excitation wavelength while AgNPs/PEI N-doped GQDs nanocomposites indicate weak fluorescence intensity at maximum 446 nm with 344 nm excitation wavelength. Based on the femtosecond transient absorption spectroscopy measurements, this emission quenching can be attributed that the excited state lifetime of PEI N-doped GQDs decreasing in the presence of AgNPs due to ultrafast electron transfer from PEI N-doped GQDs to AgNPs. It is also supported by theoretical results sensing ability of AgNPs/PEI N-doped GQDs nanocomposite is better than that of PEI N-doped GQDs. When lung adenocarcinoma cells (A549) were treated with GQDs, material-specific fluorescent signals were obtained from the cytoplasm of cells only treated with Ag/PEI N-doped GQDs, as compared with N-doped GQDs. Overall, this study shows that Ag/PEI N-doped GQDs are promising nanosystems for bioimaging applications.Öğe Anilino ve fenoksi fosfazen türevlerinin sentezi, yapılarının spektroskopik yöntemlerle incelenmesi(Çanakkale Onsekiz Mart Üniversitesi, 2011) Erdener, Diğdem; Yıldız, MustafaBu çalışmada halkalı fosfazenler trimer ve tetramerin aromatik aminler ve fenoller ile reaksiyonları incelendi. Anilino reaksiyonları için aminopodand 5, 6, 7 ve 8 sentezlenerek, ticari dianilinler satın alınarak kullanıldı. Amino podandlar ile trimerin reaksiyonundan spiro 9, 10 ve ansa 11 bileşikleri, tetramerin reaksiyonundan spiro 12 fosfazen bileşiği elde edildi. Ticari dianilinler ile trimerin reaksiyonundan bino bileşikleri 13, 14 ve 15 sentezlendi. Trimerin bisfenol ile reaksiyonundan mono-spiro fenoksifosfazen 16 ve di-spiro fenoksifosfazen 17 bileşiği, tetramerin reaksiyonundan mono-spiro fenoksifosfazen 18 bileşiği hazırlandı. Bileşik 16 ve 17'nin aminopodand 6 ile reaksiyonundan bino 19 ve spiro 20 bileşiği elde edildi. Bileşik 17' nin aminopodand 5 ve bisfenol ile reaksiyonundan spiro 21 ve 22 bileşikleri sentezlendi.Sentezlenen fosfazen bileşiklerinin yapıları, element analizi, MS, IR, 1H-NMR, 13C-NMR ve 31P-NMR spektroskopik yöntemleri ile aydınlatıldı.Öğe Chromogenic sensing, biological, and optical properties of Schiff bases of 2-amino-6-methoxybenzothiazole(Elsevier B.V., 2024) Akhüseyin Yıldız, Elif; Pepe, Yasemin; Erdener, Diğdem; Karatay, Ahmet; Boyacıoğlu, Bahadır; Ünver, Hüseyin; Yapar, Gönül; Demir, Neslihan; Yıldız, MustafaIn this study, a new series of Schiff base benzothiazole derivatives were synthesized and their structures were characterized by elemental analysis, FTIR, UV–VIS and NMR spectroscopy. The biological, sensory and photophysical properties of the benzothiazole derivatives were investigated. The sensing properties of the compounds were investigated UV–VIS spectroscopically, calorimetrically and theoretically. All compounds showed colorimetric, fluorometric and spectroscopic sensor properties for F−, CN−, AcO−, H2PO4− and OH− anions. Furthermore, DNA binding, DNA cleavage and antioxidant activities of compounds 1-4 were investigated. All compounds affected pBR322 DNA both hydrolytically and oxidatively, interacted with DNA in electrostatic mode, and also compounds 1 and 2 exhibited antioxidant activity close to standard BHT. In addition, the effects of electron donating and accepting substituents on the emission properties and charge transfer dynamics were investigated by fluorescence and femtosecond transient absorption spectroscopy measurements, respectively. According to fluorescence measurements, compounds 3 and 4 showed emission signal, while compounds 1 and 2 showed fluorescence quenching and weaker emission signal.Öğe Colorimetric chemical sensing properties of 3-amino-4-hydroxybenzene- sulfonic acid-based Schiff bases containing electron donor-acceptor groups(Elsevier, 2023) Akhüseyin Yıldız, Elif; Pepe, Yasemin; Erdener, Diğdem; Karatay, Ahmet; Boyacıoğlu, Bahadır; Ünver, Hüseyin; Yapar, Gönül; Yıldız, Mustafa; Demir, NeslihanA new series of aminobenzene sulfonic acid-based Schiff bases (1-3) were synthesized from the reaction of 3-amino-4-hydroxybenzenesulfonic acid with 5-methyl, 5-nitro and 5-bromo-salicylaldehyde. The colorimetric and UV-Vis spectroscopic responses of compounds in DMSO to addition of equivalent number of anions (F-, Br-, I-, CN-, SCN-, ClO4-, HSO4-, AcO-, H2PO4-, N3- and OH-) were investigated. Additionally, biological activities of the compounds; antimicrobial and DNA binding properties, were investigated. A DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical method was used to measure antioxidant activity, and 4-hydroxy-3-(2-hydroxy-5-methylbenzylideneamino)benzene sulfonic acid (1) displayed greater antioxidant activity than butylated hydroxytoluene (BHT). Studied compounds demonstrated emission properties over a wide range of visible spectrum, and compound 4-hydroxy-3-(2-hydroxy-5-nitrobenzylideneamino)benzenesulfonic acid (2) has hyp-sochromic shift by incorporating NO2 in comparison with other compounds. Femtosecond transient absorption spectroscopy measurements showed that compounds 4-hydroxy-3-(2-hydroxy-5-nitrobenzylideneamino)benze-nesulfonic acid (2) and 3-(5-bromo-2-hydroxybenzylideneamino)-4-hydroxybenzenesulfonic acid (3), incorpo-rated nitro and bromine groups and possessing electron accepting features have fast triplet transition. This study provides a novel design strategy for biological activity and colorimetric probing features of aminobenzene sul-fonic acid-based Schiff bases.Öğe Effect of group electronegativity on spectroscopic, biological, chromogenic sensing and optical properties of 2-formyl-benzene sulfonic acid sodium salt-based Schiff bases(Elsevier B.V., 2023) Akhüseyin Yıldız, Elif; Pepe, Yasemin; Erdener, Diğdem; Karatay, Ahmet; Boyacıoğlu, Bahadır; Ünver, Hüseyin; Yapar, Gönül; Demir, Neslihan; Yıldız, Mustafa; Elmalı, AyhanIn this study, 2-formylbenzenesulfonic acid sodium salt-based Schiff bases were synthesized from the reactions of 2-formylbenzenesulfonic acid sodium salt with 2-amino-4-chlorophenol and 2-amino-4-methylphenol. The structure of the compounds was determined by FTIR, UV–Vis and NMR spectroscopy methods using both experimental and DFT methods. The anion sensor properties of the compounds were investigated both UV–Vis spectroscopically and calorimetrically. In addition, the antimicrobial activities, interactions with DNA, DNA cleavage and antioxidant activities of Schiff bases were investigated. Additionally, the effects of group electronegativity on the spectroscopic, biological, chromogenic sensing and optical properties of chlorine and methyl side groups and sodium 2-sulfobenzalidene-aminophenol-based Schiff bases were investigated.Öğe Exploring Charge Transfer Mechanisms in Schiff Base-Modified N-Doped GQDs: Insights from DFT and Pump-Probe Spectroscopy for Bioimaging Applications(Wiley-V C H Verlag Gmbh, 2024) Hance, Saadet; Erdener, Diğdem; Özturk, Berfin İlayda; Akhüseyin Yıldız, Elif; Karatay, Ahmet; Boyacıoğlu, Bahadır; Ünver, Hüseyin; Yıldız, MustafaIn recent developments, graphene quantum dots (GQDs) have emerged as valuable tools for imaging and biosensing. Various modifications on the GQDs with any desired functionality and attachment of organic molecules and/or nanostructures allow tuning their photophysical properties as well as charge transfer dynamics for bioimaging applications. This study focuses on synthesizing and characterizing of polyethyleneimine-functionalized nitrogen-doped GQDs (NC1), Schiff base- functionalized nitrogen-doped GQDs (NC2), and silver nanocomposites of these Schiff base-functionalized nitrogen-doped GQDs (NC3). We explore their absorption and emission properties to understand their interactions in the ground state. Furthermore, ultrafast transient absorption spectroscopy measurements reveal that the presence of NC3 shortens the excited state lifetime of NC1 due to charge transfer, resulting in reduced fluorescence intensity. Both experimental and DFT results suggest the potential of NC3 for bioimaging and sensing applications, making them promising candidates for phototheranostic purposes.Öğe Spectroscopic study, antimicrobial activity and crystal structures of N-(2-hydroxy-5-nitrobenzalidene)4-aminomorpholine and N-(2-hydroxy-1-naphthylidene)4-aminomorpholine(Elsevier, 2005) Yıldız, Mustafa; Ünver, H.; Dülger, Başaran; Erdener, Diğdem; Ocak, N.; Erdönmez, A.; Durlu, Tahsin NuriSchiff bases N-(2-hydroxy-3-nitrobenzalidene)4-aminomorpholine (1) and N-(2-hydroxy- I -naphthylidene)4-aminomorpholine (2) were synthesized from the reaction of 4-aminomorpholine with 2-hydroxy-5-nitrobenzaldehyde and 2-hydroxy- 1 -naphthaldehyde. Compounds 1 and 2 were characterized by elemental analysis, IR, H-1 NMR, C-13 NMR and UV-Visible techniques. The UV-Visible spectra of the Schiff bases with OH group in ortho position to the imino group were studied in polar and nonpolar solvents in acidic and basic media. The structures of compounds 1 and 2 have been examined cyrstallographically, for two compounds exist as dominant form of enol-imines in both the solutions and solid state. The title compounds 1 and 2 crystallize in the monoclinic space group P2(1)/c and P2(1)/n with unit cell parameters: a=8.410(1) and 11.911(3), b=6.350(9) and 4.860(9), c=21.728(3) and 22.381(6) angstrom, beta=90.190(1) and 95.6(2)degrees, V=1160.6(3) and 1289.5(5) angstrom(3), D-x = 1.438 and 1.320 g cm(-3), respectively. The crystal structures were solved by direct methods and refined by full-matrix least squares. The antimicrobial activities of compounds 1 and 2 have also been studied. The antimicrobial activities of the ligands have been screened in vitro against the organisms Escherichia coli ATCC 11230, Staphylococcus aureus ATCC 6538, Klebsiella pneumoniae UC57, Micrococcus luteus La 297 1, Proteus vulgaris ATCC 8427, Pseudomonas aeruginosa ATCC 27853, Mycobacterium smegmatis CCM 2067, Bacillus cereus ATCC 7064, Listeria monocytogenes ATCC 15313, Candida albicans ATCC 1023 1, Kluyveromyces fragilis NRRL 2415, Rhodotorula rubra DSM 70403, Debaryomyces hansenii DSM 70238 and Hanseniaspora guilliennondii DSM 3432. 0 2004 Elsevier B.V. All rights reserved.Öğe Sübstitüe halkalı fosfazenlerin sentezi ve yapılarının spektroskopik yöntemlerle incelenmesi(Çanakkale Onsekiz Mart Üniversitesi, 2006) Erdener, Diğdem; Yıldız, MustafaSÜBSTİTÜE HALKALI FOSFAZENLERİN SENTEZİ VE YAPILARININSPEKTROSKOPİK YÖNTEMLERLE İNCELENMESİÖZETBu çalışmada 2,2'-metilenbis(4-klorofenol)'un sodyum tuzu ile hekzaklorosiklotrifosfazenTHF ortamında etkileştirildi. Di sübstitüe fenoksi fosfazen (2, 3) bileşikleri sentezlendi. Fenoksifosfazen (2, 3) ile ter-butil aminin aşırısının THF ortamındaki reaksiyonundan geminal-di(ter-butilamino)fenoksi fosfazen (4, 5) bileşikleri elde edildi.Sentezlenen fosfazen bileşiklerinin yapıları, element analizi, IR, 1H-, 13C-, 31P-NMR ve MSspektroskopik verilerinden faydalanılarak aydınlatıldı. Ayrıca bileşik 2' nin yapısı X-ışınlarıkristallografisi metoduyla aydınlatıldı.Anahtar sözcükler : Hekzaklorosiklotrifosfazen, Fenoksi Fosfazen, Geminal fosfazen,Spektroskopi, X-ışınları kristallografisiÖğe Superb ruthenium(ii) complex melody: Uncovering its hidden catalytic and biological properties(Pergamon-Elsevier Science Ltd, 2024) Duman, Sibel; Dervişoğlu, Gökhan; Özdemir, Fethi Ahmet; Şerbetci, Zafer; Erdener, Diğdem; Dayan, OsmanAliphatic/aromatic nitrogen-substituted ligands have a very important role in ruthenium chemistry. Polydentate ligands with N-substituted pyridine rings are notable for their ability to easily modify the electronic and steric properties of ruthenium. In this study, the catalytic and biological activities of the [RuCl2(NNN)(CH3CN)] (NNN: 2,6-di(1H-pyrazol-3-yl)pyridine)) complex were examined for two different applications. Firstly, the superb Ru(II) complex was used to catalyze the methanolysis of NaBH4, and its initial rate was calculated as 69360 mLH(2)min(-1)g(cat)(-1). Secondly, the biological activities of the superb Ru(II) complex were examined. Accordingly, it was determined that this homogeneous complex showed anti-microbial activity on all bacteria used in the study, among the Gram-positive bacteria used in the study, the best result belongs to the Bacillus cereus EMC 19 bacterium with 8 mm, while among the Gram-negative bacteria, the best zone diameter belongs to the Pseudomonas aeruginosa DSM 50071 bacterium with 5 mm. However, it was observed that zone diameters varied between 8 mm and 3 mm. Compared to the control group, it was determined that 0.25 mg/mL concentration had 94.87%, 0.5 mg/mL concentration 96.10%, 1 mg/mL concentration 96.50%, and 2 mg/mL concentration 97.09% cytotoxic activity on the SH-SY5Y cell line. it was determined that all doses of the superb Ru(II) complex used in the study showed anti-cancer activity, but the anticancer activity shown at low doses was statistically more significant at the p < 0.05 level.Öğe Synthesis and Characterization of a Carbazole-Based Schiff Base Capable of Detection of Al3+ in Organic/Aqueous Media(Springer/Plenum Publishers, 2022) Erdener, Diğdem; Kaya, İsmetA new fluorescence probe (L) selectively detecting Al3+ ions was synthesized via the condensation reaction, and characterized using UV-Vis, FT-IR, H-1-NMR and C-13-NMR spectroscopic techniques. The limit of detection for Al3+ ions of this synthesized probe was found to be 9.29 x 10(-7) M, while the Ka constant value was determined to be 1.64 x 10(4) M-1. The stoichiometric binding ratio of L-Al3+ was found to be 2:1 using the Job's plot method, and this ratio was also confirmed by H-1-NMR titration and mass spectrometry. The recyclability of the chemosensor was found by the fluorescence method through the addition of EDTA to the L-Al3+ solution. The obtained data showed that the carbazole-based Schiff base acted as an ideal chemosensor for Al3+.Öğe Synthesis and characterization of a highly selective turn-on fluorescent chemosensor for Sn2+ derived from diimine Schiff base(Elsevier, 2021) Kolcu, Feyza; Erdener, Diğdem; Kaya, İsmetThis study is exploratory in proposing a Schiff base (Ligand=L), which was designed and synthesized through one-step condensation reaction using 2,2 '-bithiophene-5-carboxaldehyde and 4,4'-diaminotriphenylamine (DATPA), was employed for fluorescent detection of the presence of Sn2+ ions. The ligand was well-characterized by infrared (FT-IR), UV-vis spectroscopy, H-1 and C-13 nuclear magnetic resonance (NMR) analyses. The chelation of the ligand with Sn2+ ion caused a decrease in the optical band gap in the UV-vis absorption spectrum of the ligand upon the addition of Sn2+ ions. The binding of L to Sn2+ caused a blue shift due to an internal charge transfer (ICT). The synthesized L was conceivable to be an outstanding receptor to detect Sn2+ ions with a remarkable fluorescent enhancement due to a potent chelation enhanced fluorescence (CHEF) effect. Non fluorescent ligand executed a fast response and highly sensitive turn-on fluorescent sensing behavior to detect Sn2+ ions via 1:2 (ligand:metal) complexation without any interference from other metal cations. The ligand's specificity was indicated with an observation of no transition in colour with any other metal cations. The selectivity of the probe for Sn2+ was confirmed by the absence of any interference from other competitive cationic species. The calculated limit of detection (LOD) and binding constant (K-a) were found to be 3.14 x 10(-7) M and 6.8 x 10(9) M-2, respectively. The synthesized ligand was of use for the devise of metal sensors based on diimine Schiff base.Öğe Synthesis and characterization of a pyrene-based Schiff base and its oligomer: Investigation of fluorescent Cr3+ probe(Elsevier, 2022) Karacan Yeldir, Elif; Erdener, Diğdem; Kaya, İsmetIn this study, a unique Schiff base (SP) was synthesized from 1-aminopyrine (1-AP) and salicylaldehyde (SA) compounds. The obtained oligomer of this Schiff base was carried out by the oxidative polymerization method. The structural characterizations of 2-((pyren-1-yl-imino)methyl)phenol (SP) and oligo-2-((pyren-1-yl-imino)methyl)phenol (OSP) by FT-IR, H-1 NMR and C-13 NMR measurements, electrochemical properties by cyclic voltammetry (CV); optical properties by UV/Vis studies and photoluminescence (PL) spectrophotometry; thermal stability were performed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The molecular weight of the obtained oligomer was determined using gel permeation chromatography (GPC). Accordingly, Mn and Mw values of OSP were found to be 2800 and 3150 Da, respectively. The imine bond provided the structures with high thermal stability, and the maximum mass loss temperatures (T-max) of SP and OSP were found to be 350(0) and 343 degrees C, respectively. PL study showed that SP could be used as a Cr3+ sensor among a series of metals. The results revealed that the limit of detection (LOD) value of SP was 1.03 x 10(-)(9) M and was not affected by other ions in the environment.Öğe Synthesis of a cationic ruthenium(ii) complex and its non-enzymatic glucose-sensing properties(Royal Society of Chemistry, 2023) Dayan, Serkan; Özdemir, Namık; Erdener, Diğdem; Dayan, Osman; Çetinkaya, BekirThe new cationic ruthenium(ii) complex (2) was synthesized via the reaction of N,N′-[1,1′-(pyridine-2,6-diyl)bis(ethan-1-yl-1-ylidene)]bis(2-ethyl-6-methylaniline) and [RuCl2(p-cymene)]2, and it was fully characterized using NMR, FT-IR, single-crystal X-ray diffraction, ESI-MS, UV-vis, CV and thermal analysis methods; theoretical computational characterizations and geometric parameters for 2 were also carried out via quantum chemical calculations using the density functional theory (DFT) method. In addition, the synthesized Ru(ii) complex (2) was immobilized on fabricated RGO-TiO2@FTO to evaluate its non-enzymatic biosensing properties, and the sensing properties of the resulting Ru(ii)-RGO-TiO2@FTO electrode were recorded. As a glucose-sensing model, at an applied potential of +0.34 V, the Ru(ii)-RGO-TiO2@FTO electrode presented a moderately good sensitivity of 62.69 μA mM−1 cm−1. Various modifications of Ru(ii)-RGO-TiO2@FTO-type electrodes, such as the metal complex, and material types and ratios, will enable the design of future biosensor devices with improved performance.Öğe Synthesis of pyrene and pyrrole-appended fluorescent turn-off sensor toward Cr(VI) detection: Chemical oxidative and electrochemical polymerization of carboxamide(Elsevier B.V., 2024) Kaya, İsmet; Karacan Yeldir, Elif; Kolcu, Feyza; Erdener, DiğdemA carboxylic amide compound containing pyrrole and pyrene groups, referred to as PP, was synthesized and characterized for its structural, optical, and electrochemical properties. Upon excitation with 320 nm light, PP displayed blue emission at 387 nm, which was found to be quenched due to chelate formation in the presence of Cr(VI). Conducted competition experiments involving chloride salts of Ag+, Al3+, Cd2+, Co2+, Cr3+, Fe3+, Hg2+, K+, Mn2+, Ni2+, Pb2+, Sn2+, and Zn2+ demonstrated the notable selectivity of compound PP towards Cr(VI) ions. This selectivity was evidenced by a pronounced turn-off fluorescent effect, attributed to a chelation-enhanced quenching (CHEQ) mechanism by the formation of 1:2 chelation between Cr(VI) and the ligand PP. Moreover, addition of EDTA to PP– Cr(VI) chelation recovered the fluorescence offering receptor PP as a reversible sensor. The PP probe demonstrated remarkable selectivity in detection Cr(VI) ions among various metallic ions, displaying a limit of detection (LOD) value of 0.106 µM. Chemical oxidative and electropolymerization methods were employed to synthesize two distinct polymers, namely Poly(PP)-O and Poly(PP)-E, respectively. The electropolymerization of PP was carried out in 0.1 M TBAF6P serving as a supporting electrolyte solution, while oxidative polymerization was conducted in the presence of FeCl3. Mass average molecular weight of the oxidative polymerization product was 5200 Da, as determined by GPC analysis. Thermal characterization was performed via TG-DTA-DTG curves. The electropolymerization product of PP coated on the ITO surface was further characterized by SEM.Öğe Synthesis of Silver Nanoparticles Using Porella pinnata L. Extract and Evaluation of Biological Activity(Pleiades Publishing Inc, 2024) Şimşek, Özcan; Demir, Neslihan; Erdener, Diğdem; Karakaş, İlke; Hacıoğlu Doğru, NurcihanDeveloping an eco-friendly method for producing nanomaterials is an area of significant research and commercial interest owing to its numerous applications in various disciplines. This study used a simple green synthesis approach to produce silver nanoparticles (AgNPs) using Porella pinnata L. aqueous extract. Phytochemical constituents of P. pinnata were identified by Gas Chromatography and Mass Spectroscopy (GC-MS). The optical, structural, and morphological characteristics of the AgNPs were found using UV visible absorption spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), Zeta Potential, and scanning electron microscope (SEM). The AgNPs had an average size of 76-84 nm and were mostly spherical. Considering the antimicrobial and antibiofilm activity results, both aqueous extract and AgNP have significant activities against different microorganisms based on the disc diffusion, broth microdilution, and antibiofilm methods. The P. pinnata and AgNPs extracts were significantly inhibited all test culture especially Acinetobacter baumanii ATCC 19606. The agarose gel electrophoresis method showed that extract and AgNP both cleaved DNA by hydrolytic and oxidative. Although both P. pinnata and AgNP extracts have dose-dependent antioxidant activity, AgNP is more effective. Thus, green synthesis AgNPs may be a new alternative therapeutic agent for infection therapy.Öğe Synthesis, Characterization, and Cytotoxic Activities of a Schiff Base Ligand and Its Binuclear Copper(II) and Manganese(III) Complexes(Turkish Chemical Society, 2017) Uyar, Zafer; Erdener, Diğdem; Koyuncu, İsmail; Arslan, ÜlküA novel symmetrical N2O2 type Schiff base (1) and its copper (II) (2) and manganese (III) (3) complexes were synthesized and characterized by spectroscopic, analytical, and magnetic susceptibility studies. Spectroscopic and magnetic susceptibility studies suggested that copper and manganese ions are in 2+ and 3+ states and their complexes have a binuclear double stranded helical structure in the form of 2:2 (metal to ligand) stoichiometry. Cytotoxic effects of the ligand and its metal complexes against MCF-7 (human breast cancer cell line), DLD-1 (human colorectal cancer cell line), ECC-1 (human endometrium cancer cell line), DU-145 (human prostate cancer line), MDA-MB231 (human breast cancer cell line), PC-3 (human prostate cancer line) and HEK293 (normal cells) were evaluated by determining their cellular viability using the colorimetric 3-(4,5- dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide (MTT) assay. It has been found that cytotoxicity of the ligand was significantly enhanced towards cancer cells and declined towards normal HEK293 cells by metal chelation. Copper complex yielded better results in comparison with manganese complex. Particularly, copper complex showed a selective cytotoxicity, harming the cancerous cell lines while not impairing the normal cells, which is considered as the key to the future of cytotoxic therapy.Öğe Synthesis, characterization, and optimum reaction conditions of oligo-2-[(pyridine-2-yl-methylene) amino] phenol(John Wiley & Sons Inc, 2004) Kaya, İsmet; Moral, Fatma; Erdener, DiğdemThe reaction conditions of the oxidative polycondensation of 2-[(pyridine2-yl-methylene) amino] phenol (2-PMAP) with air O-2, H2O2, and NaOCl were studied in an aqueous alkaline medium between 60 and 90 degreesC. Oligo-2-[(pyridine-2-yl-methylene) amino] phenol (O-2-PMAP) was characterized with H-1 NMR, Fourier transform infrared, ultraviolet-visible, size exclusion chromatography (SEC), and elemental analysis techniques. Moreover, solubility testing of the oligomer was performed in polar and nonpolar organic solvents. With the NaOCl, H2O2, and air O-2 oxidants, the conversions of 2-PMAP into O-2-PMAP were 98, 87, and 62%, respectively, in an aqueous alkaline medium. According to SEC, the number-average molecular weight, weight-average molecular weight, and polydispersity index of O-2-PMAP were 2262 g mol(-1), 2809 g mol(-1), and 1.24 with NaOCl, 3045 g mol(-1), 3861 g mol(-1), and 1.27 with air O-2, and 1427 g mol(-1), 1648 g mol(-1), and 1.16 with air H2O2, respectively. Also, thermogravimetric analysis showed that O-2-PMAP was stable against thermooxidative decomposition. The weight loss of O-2-PMAP was 96.68% at 900 degreesC. (C) 2004 Wiley Periodicals, Inc.Öğe Tautomeric properties and crystal structure of N-[2-hydroxy-1-naphthylidene]2,5-dichloroaniline(Wiley-V C H Verlag Gmbh, 2006) Yıldız, Mustafa; Ünver, H.; Erdener, Diğdem; Ocak, N.; Erdönmez, A.; Durlu, T. NuriThe title compound has been synthesised by the reaction of 2-hydroxy-1-naphthaldehyde with 2,5-dichloroaniline. The compound was characterized by elemental analysis, IR and UV-Visible techniques. The UV-Visible spectra of the Schiff base with OH group in ortho position to the imino group was studied in polar and nonpolar solvents in acidic and basic media. The structure of compound has been examined cyrstallographically. It crystallizes in the or-thorhombic space group P2(1)2(1)2(1) with a = 6.059(1), b = 12.105(2) c = 20.006(2) angstrom, V = 1467.4(3) angstrom(3), D-x = 1.431 g.cm(-3) and Z = 4. The crystal structure was solved by direct methods and refined by full-matrix least squares. Molecule of the title compound N-[2-hydroxy-1-naphthylidene]2,5-dichloroaniline is nearly planar. The molecule contains a strong intramolecular N...H-O hydrogen bond between the imine and hydroxyl group [O1 and N1 = 2.540(4) angstrom]. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
