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Determination of the antimicrobial properties of oligo-2-hydroxy-1- naphthaldehyde
(2005) Yapici, Binnur Meri?li; Kaya, İsmet; Şenol, Dilek
Oligo-2-hydroxy-1-naphthaldehyde (OHNA) was synthesized by oxidative polycondensation using H2O2 (35%, aqueous solution), air O2 and NaOCl (34%, aqueous solution) by Kaya and Şenol and the products were characterized by spectral techniques /3/. Antimicrobial activities of the first and second fractions of OHNA were tested against Corynobacterium xerosis CCM 2824, Proteus vulgaris ATCC 6897, Staphylococcus epidermidis NRRL B-4877, S. aureus ATCC 6538, Enterobacter aerogenes ATCC 13048, Salmonella thyphimurium CCM 5445, Pseudomonas aeroginosa ATCC 27853, Escherichia coli ATCC 11230, E. coli ATCC 23998, Bacillus cereus ATCC 7064, B. cereus ATCC 99, B. subtilis ATCC 6633, Yersinia spp., Neisseria canis, Rhodotorula rubra, Kluyveromyces fragilis NRRL 2415, Saccharomyces cerevisiae ATCC 9763, S. ovarum, Debaryomyces hensenii, Hansenula anamola, Candida albicans, C. utilis, Aspergillus niger, A. fumigates, A. versicolor, A. flavus, A. parasiticus, Penicillium granulatum, P. chrysogenum, and P. herque. OHNA demonstrated antimicrobial activity against various bacteria and yeast, but did not affect filamentous fungi. ©Freund Publishing House Ltd., 2005.
Investigation of thermodynamic properties of PIBMA-PVC (50%/50%) and P-4-t-BS-PVC (50%/50%) blends systems by inverse gas chromatography
(Taylor & Francis Inc, 2005) Kaya, İsmet; Şenol, Dilek
The specific retention volumes, V-g(0),blend values of the poly (isobutyl methacrylate)-poly (vinyl chloride) (PIBMA-PVC) (50%150%) and poly (4-tertbutyl styrene)-poly (vinyl chloride) (P-4-t-BS-PVC) (50%/50%) blends-probe systems were calculated between 383 and 423 K by inverse gas chromatography technique. According to these data, the thermodynamic properties such as the sorption enthalpy (Delta H-1(s)), sorption free energy (Delta G(1)(s)), sorption entropy (Delta S-1(s)), the partial molar free energy (Delta G(1)(infinity)), and the partial molar heat of mixing, (Delta H-1(infinity)) at infinite dilution were determined for the interactions of (PIBMA-PVC) (50%/50%) and (P-4-t-BS-PVC) (50%/50%) blends with alcohols and aromatics and CHCl3 by inverse gas chromatography method in the temperature range of 383-423 K. The sorption values Delta H-1(8) and Delta S-1(s) values were observed to be exothermic, and Delta G(s)(1), Delta G(1)(infinity), and Delta H-1(infinity) values were observed to be endothermic. The Delta H-1(infinity) values of PIBMA-PVC (50%/50%) and P (-4-t-BS)-PVC (50%/50%) blends-alcohols systems changed from 9.73 to 18.17 kJ/mol and from 10.00 to 16.83kJ/mol, respectively. Flory-Huggins interaction parameters, chi(12), chi(13), chi(14), chi 1(23) and chi 1(24) values of PVC, PIBMA, P (4-t-BS), PIBMA-PVC (50%/50%) and P (-4-t-BS)-PVC (50%150%) blend systems were determined at 413-423 K. In addition, chi'(23) and chi'(24) values of alcohols changed from 1.191 to 2.473 and from 1.342 to 1.839 for PIBMA-PVC (50%/50%) and P (4-t-13S)PVC (50%/50%) blends, respectively, at 413 K.
Oligo 2-hidroksi-1-naftaldehitin schiff bazı oligomerlerinin sentez ve özelliklerinin incelenmesi
(Çanakkale Onsekiz Mart Üniversitesi, 2001) Şenol, Dilek; Kaya, İsmet
oz Bu çalışmada, 2-hidroksi-l-naftaldehitin, hava oksijeni, sodyumhipoklorit ve H2O2 ile oksidatif polikondensasyon reaksiyon koşulları ve ürünleri incelendi. NaOCl'nin O2 ve H2O2den daha aktif olduğu gözlendi. Optimum reaksiyon şartlan belirlendi. OHNA, HNA'nın hava oksijeni, H2O2 ve NaOCl'nin 50-95°C arasında, bazik sulu çözelti ortamında, oksidatif polikondensasyonundan sentezlendi. Ürünler, 'H-NMR, FT-IR, UV-Vis, elementel analiz ve TGA ile karakterize edildi. HNA'nın yaklaşık % 67'si OHNA'ya dönüşüldüğü anlaşıldı. TGA, OHNA'nın termo-oksidatif bozunmaya dirençli olduğunu gösterdi. OHNA'nın kütle kaybı 500°C'de %30.56 olarak bulundu. Ayrıca OHNA'nın anilin, /P-aminofenol ve trietilenglikol-bis.v-(4- aminofenileter) ile kondensasyonundan yeni oligomerik Schiff bazları sentezlendi bunların yapı özellikleri belirlendi. Anahtar Kelimeler: Oligo 2-hidroksi-l-naftaldehitin sentezi ve karakterizasyonu, oksidatif polikondenzasyon, oligomer schiff bazları.
Study of changes in polymer-probe interactions with stabilization temperature of a column contained polyacrylonitrile by using inverse gas chromatography
(Marcel Dekker Inc, 2004) Kaya, İsmet; Şenol, Dilek
A column filled with chromosorb W (45-60 mesh) coated with polyacrylonitrile (PAN) was conditioned at different temperature, 150, 175, 200, 225, 260, and 275degreesC under nitrogen current. After each stabilization the specific retention volumes, V-g(0), of probes were determined by using inverse gas chromatography (IGC) techniques for acetone, acetonitrile, p-xylene, n-propanol, pyridine, and n-hexane as probes in the temperature range 50-150degreesC. When temperature changed from 150 to 275degreesC specific retention volumes, V-g(0), and values of probes were increased. Also, V-g(0) values of polar probes were higher than those of unpolar probes. A film of PAN homopolymer was heated in an oven at 150, 175, 200, 225, 260, and 275degreesC under nitrogen current (the conditions are the same as those of coated PAN in the column). After each heating event, PAN films were used for Fourier transform infrared spectroscopy (FT-IR) measurements. The FT-IR spectra of PAN film (when temperature increased from 150 to 275degreesC), showed some new peaks at the 740-3350cm(-1) region and increased intensity of some peaks between 2900-3500cm(-1) and 1100-1700cm(-1). According to differential scanning calorimeter (DSC) analysis, the glass transition temperature of PAN found to be 130degreesC.
Synthesis and characterization of oligo-2-hydroxy-1-naphthaldehyde and its Schiff base oligomers
(John Wiley & Sons Inc, 2003) Kaya, İsmet; Şenol, Dilek
In this study, oligo-2-hydroxy-1-naphthaldehyde (OHNA) was synthesized from the oxidative polycondensation of 2-hydroxy-1-naphthaldehyde (HNA) with air oxygen, NaOCl and H2O2 in an aqueous alkaline medium at 50-95degreesC. We determined the products and the oxidative polycondensation reaction conditions of HNA with oxidants such as air oxygen, NaOCl, and H2O2. In these reactions, H2O2 was more active than air oxygen and NaOCl and their optimum reaction conditions were studied. The products were characterized by H-1-NMR, FTIR, UV-visible, and elemental analysis. The respective number-average molecular weight, mass-average molecular weight, and polydispersity index values of OHNA and its Schiff base oligomers (compounds 1, 2, and 3) were found to be 500 g mol(-1), 1880 g mol(-1), and 3.75 for OHNA; 670 mol(-1), 2490 mol(-1), and 3.71 for compound 1; 390 g mol(-1), 1080 g mol(-1) and 2.77 for compound 2; and 320 g mol(-1), 670 g mol(-1), and 1.85 for compound 3. At the optimum reaction conditions, the yields of the reaction products were found to be 77.0% O-2, 78.0% H2O2, and 75.4% NaOCl. About 80% of the HNA was converted into OHNA. In addition, new Schiff based oligomers were synthesized from the condensation reaction of OHNA with p-aminophenol, triethyleneglycol bis(4-aminophenyl ether), and aniline and their structures and properties were determined. Thermogravimetric and dynamic thermal analyses showed OHNA and its Schiff base oligomers to be stable against thermooxidative decomposition. The weight losses of OHNA and its Schiff base oligomer compounds 1, 2, and 3 were found to be 5% at 175, 225, 190, and 230degreesC, respectively; 50% at 900, 590, 650, and 620degreesC, respectively; and 60, 80, 85, and 82%, respectively, at 1000degreesC. (C) 2003 Wiley Periodicals, lnc.
Synthesis and characterization of oligo-salicylidene-3-amino-1,2,4-triazole and oligo-2-hydroxy naphthalidene-3-amino-1,2,4-triazole
(Taylor & Francis Inc, 2005) Erçağ, Ayşe; Kaya, İsmet; Şenol, Dilek; Koyuncu, Sermet
In this study, the oxidative polycondensation reaction conditions of oligo-salicylidene-3-amino-1, 2, 4-triazole (OSAT) and oligo-2-hydroxy naphthalidene-3-amino-1, 2, 4-triazole (OHNAT) with air O-2, H2O2, and NaOCl were studied in an aqueous alkaline medium at 80 degrees C. The oligo-salicylidene-3-amino-1, 2, 4-triazole and oligo-2-hydroxy naphthalidene-3-amino-1, 2, 4-triazole were characterized by H-1-nuclear magnetic resonance (NMR), Fourier transform-infrared (FT-IR), ultraviolet-visible spectrometry (UV-Vis), size exclusion chromatography (SEC), and elemental analysis techniques. According to the SEC analysis, the number average-molecular weight (M-n), weight average-molecular weight (M-w), and polydispersity index (PDI) values of OSAT and OHNAT were found to be 1980 g mol(-1), 5115 g mol(-1), and 2.58 and 1752 g mol(-1), 4300 g mol(-1), and 2.45, respectively. Also, thermogravimetric (TG) analyses were shown to be unstable for oligo-salicylidene-3-amino-1, 2, 4-triazole and oligo-2-hydroxy naphthalidene-3-amino-1, 2, 4-triazole against thermo-oxidative decomposition. The weight losses of OSAT and OHNAT were found to be 97.30% and 98.48% at 900 degrees C, respectively.
Synthesis and characterization of polyphenol derived from Schiff bases containing methyl and carboxyl groups in the structure
(Taylor & Francis Ltd, 2015) Kaya, İsmet; Kartal, Emre; Şenol, Dilek
In this study, a series of Schiff bases (CBAA4MP, CBAA5MP, and CBAA3MP) which differ from each other based on the position of methyl group were synthesized. The derived monomers were changed into their polymer kind (P-CBAA4MP, P-CBAA5MP, and P-CBAA3MP) by oxidative polycondensation in aqueous alkaline medium using NaOCl as the oxidant. The structures of the synthesized compounds were enlightened using FT-IR, UV-vis, H-1-NMR, and C-13-NMR analyses. The H-1-NMR and C-13-NMR results showed that polymerization preceded by C-C and C-O-C couplings of the monomer units (phenylene and oxyphenylene groups). The molecular weight dispersion of the polymers was designated by size exclusion chromatography analysis. Electrochemical ( [GRAPHICS] ) and optical (E-g) band gaps of the synthesized substances are measured using CV and UV-vis techniques, in order of. Solid state electrical conductivities of both doped and undoped states of the synthesized polymers were evaluated. Also, the effects to the electrochemical band gaps values of ortho, meta, and para positions of methyl group in the structures of polymers were examined from CV measurements.
Synthesis and characterization of Schiff base, Co(II) and Cu(II) metal complexes and poly(phenoxy-imine)s containing pyridine unit
(Elsevier S.A., 2021) Kaya, İsmet; Daban, Sevil; Şenol, Dilek
In the first stage, two different Schiff base ligands were prepared by the condensation of 2-amino-5-bromopyridine and 2-amino-5-chloropyridine with salicylaldehyde in methanol at the molar ratio of 1:1. Ligands: C12H9ON2Br (L1), C12H9ON2Cl (L2). In the second stage, four different metal complexes were obtained from Schiff bases with Co(OAc)2·4H2O and Cu(OAc)2·2H2O Molecular formulas of the metal complexes obtained were [Co2(L1)2(H2O)(OCH3)]H2O, [Cu2(L1)2(H2O)(OCH3)]H2O, [Co2(L2)2(H2O)(OCH3)]H2O and [Cu2(L2)2(H2O)(OCH3)] H2O. In the third stage, ortho-vanillin (VAN) was polymerized via oxidative polycondensation in aqueous alkaline medium with air as oxidant. Then, poly(phenoxy-imine)s were synthesized from condensation reactions of poly (ortho-vanillin) (PVAN) with 2-amino-5-bromopyridine and 2-amino-5-chloropyridine in THF medium at 60 °C. All synthesized compounds were characterized by spectral and electrochemical techniques. Thermal properties of the compounds were determined by TGA-DTA and DSC analyses. The molecular weights of the polymers were calculated from SEC analyses. Poly[2-((5-bromopyridin-2-yl-imino)methyl)-6-methoxyphenol] (PVANBr) and poly[2-((5-chloropyridin-2-yl-imino)methyl)-6-methoxyphenol] (PVANCl) were determined to have electrical conductivity of 10−3 S cm−1. Electrochemical band gaps (Eg’) of PVANBr and PVANCl were calculated as 2.10 and 1.95 eV, respectively. Initial decomposition temperatures of [Co2(L1)2(H2O)(OCH3)]H2O, [Cu2(L1)2(H2O)(OCH3)]H2O, [Co2(L2)2(H2O)(OCH3)]H2O and [Cu2(L2)2(H2O)(OCH3)]H2O were found to be 309, 271, 305 and 259 °C, respectively.
Synthesis, characterization and antimicrobial properties of 4-[(4-hydroxybenzylidene) amino] phenol and its polymer
(World Scientific Publ Co Pte Ltd, 2007) Kaya, İsmet; Çulhaoğlu, Süleyman; Şenol, Dilek
The oxidative polycondensation reaction conditions of 4-[(4- hydroxybenzylidene) amino] phenol (4- HBAP) were studied with H2O2, air oxygen and NaOCl in an aqueous alkaline medium between 50 and 90 C. The structures of the obtained monomer and polymer were confirmed by FT-IR, UV-Vis, H-1- and C-13-NMR and elemental analysis. The characterization was made by TG-DTA, size exclusion chromatography (SEC) and solubility tests. At the optimum reaction conditions, the yield of poly[ 4-(4- hydroxybenzylidene amino) phenol] (P-4-HBAP) was found to be 48.3% (for H2O2 oxidant), 80.5% (for air O-2 oxidant) and 86.4% ( for NaOCl oxidant). According to the SEC analysis, the number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersity index (PDI) values of P-4-HBAP was found to be 8950, 10970 g mol(-1) and 1.225, respectively, using H2O2; and 11610, 15190 g mol(-1) and 1.308 respectively, using air O-2 and 7900, 9610 g mol(-1) and 1.216, respectively, using NaOCl. According to TG-DTA analyses, P-4-HBAP was more stable than 4- HBAP against thermal decomposition. The weight loss of P-4-HBAP was found to be 49.27% at 1000 C. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) values calculated from electrochemical measurement. Electrochemical energy gaps (Eg ') of 4- HBAP and P-4-HBAP were found to be -5.46, -5.28; -2.26, -2.67; 3.20 and 2.61 eV, respectively. According to UV-Vis measurements, optical band gap (Eg) of 4- HBAP and P-4-HBAP were found to be 3.34 and 3.01 eV, respectively. Also, antimicrobial activities of 4- HBAP and P-4-HBAP were examined against selected some bacteria. The electrical conductivity of the polymer was measured after doping with iodine.
Synthesis, characterization, and thermal properties of oligo-2-hydroxyphenylbenzaldimine
(Marcel Dekker Inc, 2004) Kaya, İsmet; Şenol, Dilek; Koyuncu, Sermet
In this study, the oxidative polycondensation reaction conditions of 2-hydroxyphenylbenzaldimine (HPBA) with air oxygen and NaOCl were studied in an aqeous alkaline medium between 50 and 90degreesC. The product was characterized by H-1-NMR, FT-IR, UV-Vis, size exclusion chromatography (SEC), and element analysis techniques. Solubility testing of oligo-2-hyroxyphenylbenzaldimine was investigated by organic solvents such as DMF, THF, DMSO, methanol, ethanol, CHCl3, CCl4, toluene acetonitrile, ethyl acetate, conc. H2SO4, and aqueous alkaline solution. 2-Hydroxyphenylbenzaldimine (96%) was converted to oligomer by oxidation in an aqueous alkaline medium. According to solubility in water, oligo-2-hydroxyphenylben-zaldimine separated into two fractions: oligo-2-hydroxyphenylbenzaldimine (OHPBA-1, undissolved in water) and oligo-2-hydroxyphenylbenzaldimine (OHPBA-II, dissolved in water). According to the SEC technique, the number average molecular weight (M.), mass average molecular weight (M,), and polydispersity index (PDI) values of OHPBA-1 and OHPBA-II were found to be 2166 g mol(-1), 2591 g mol(-1), and 1.196; 1736 g mol(-1), 2509 g mol(-1), and 1.445, respectively. Also, differential thermal analysis (DTA) and thermo gravemetric analyses (TGA) were shown to be stable of oligo-2-hydroxyphenylbenzaldimine against thermo-oxidative decomposition. The weight loss of OHPBA was found to be 93.63% at 1000degreesC.
Thermodynamic interactions and characterisation of poly[(glycidyl methacrylate-co-methyl, ethyl, butyl) methacrylate] by inverse gas chromatography
(Elsevier Sci Ltd, 2002) Kaya, İsmet; İlter, Zülfiye; Şenol, Dilek
Poly(glycidyl methacrylate-co-methyl methacrylate) poly(GMA-co-MMA), poly(glycidyl methacrylate-co-ethyl methacrylate) poly(GMA-co-EMA) and poly(glycidyl methacrylate-co-butyl methacrylate) poly(GMA-co-BMA) were synthesized in 1,4-dioxane solution using 2,2'-azobisisobutyronitrile (AIBN) as initiator at 60 degreesC. The copolymer compositions were determined by H-1 NMR analysis. The FTIR and 13 C NMR spectra of the copolymers have been discussed. According to TG, carbonaceous residue values of poly(GMA-co-MMA), poly(GMA-co-EMA) and poly(GMA-co-BMA) were found to be 3.00, 4.00 and 4.20%, respectively, at 500 degreesC. Some thermodynamic quantities such as the sorption enthalpy, DeltaH(1)(s), the sorption entropy, TDeltaS(1)(s), the sorption free energy, DeltaG(1)(s), the partial molar free energy, DeltaG(1)(infinity), the partial molar heat of mixing, DeltaH(1)(infinity), at infinite dilution were obtained for the interactions of poly[(glycidyl methacrylate-co-methyl, ethyl, butyl) methacrylate] with n-alkanes, aromatics, CCl4, 1-chloro-propane, 1-chloro-butane and 1,4-dioxane by inverse gas chromatography method in the temperature range of 363-453 K. The specific retention volumes, V-0, the weight fraction activity coefficients of solute probes at infinite dilution, Omega(1)(infinity), Flory-Huggins thermodynamic interaction parameters, chi(12)(infinity) between polymers and solvents were determined. Also, the solubility parameters, 82, of the poly(GMA-co-MMA), poly(GMA-co-EMA) and poly(GMA-co-BMA) was found to be 30.85, 25.83, 25.00 (J cm(-3))(0.5) and 31.94, 26.59, 25.71 (J cm(-3))(0.5) from slope and intercept of [(delta(1)(2) IRT) - chi(12)(infinity)/V-1] = (2delta(2)/RT)delta(1) - delta(2)(2)/IRT equation, at 433, 423 and 393 K, respectively. The glass transition temperature, T-g, of the poly(GMA-co-MMA), poly(GMA-co-EMA) and poly(GMAco-BMA) was found to be 373, 355 and 334 K, respectively, by DSC and inverse gas chromatography. (C) 2002 Published by Elsevier Science Ltd.

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