Tanil Akyuz

Adsorption of 2,2′-bipyridyl onto sepiolite, attapulgite and smectite group clay minerals from anatolia: The FT-IR and FT-Raman spectra of surface and intercalated species

The adsorption of 2,2′-bipyridyl by natural sepiolite, attapulgite, hectorite, saponite and natural and ion exchanged (Mn, Fe, Co, Ni, Cu, Zn or Sn) bentonites has been investigated by FT-IR and FT-Raman spectroscopy. Spectroscopic results indicate that most of the adsorbed molecules are coordinated to either exchangeable cations (in the case of smectite group clays) or Lewis acidic centres (in the case of sepiolite and attapulgite) as bidentate ligands. The formation of monoanionic surface species has also been detected, to a relatively small extent. No physisorbed surface species has been observed. XRD patterns and UV-visible spectra of the samples are also recorded for additional information.

Pigment analyses of a portrait and paint box of Turkish artist Feyhaman Duran (1886–1970): The EDXRF, FT-IR and micro Raman spectroscopic studies

The samples obtained from nine different places of Ataturk portrait (oil on canvas, 86 cm×136 cm) by Feyhaman Duran (1886-1970), one of the famous Turkish painters of the 20th century, together with five pigment samples (two different white, two different yellow and blue), obtained as powders from artists paint box, were analysed by EDXRF, FT-IR and micro-Raman spectroscopic methods, in order to characterise the pigments used by the artist. Informative Raman signals were not obtained from most of the samples of the portrait, due to huge fluorescence caused by the presence of impurities and organic materials in the samples, however the Raman spectrum of the sample from skin coloured part of the portrait and the pigment samples obtained from the paint box of the artist were found to be very informative to shed light on the determination of the pigments used. Analysis revealed the presences of chrome yellow (PbCrO4), strontium yellow (SrCrO4) and Cadmium yellow (CdS) as yellow, chromium oxides (Cr2O3 and Cr2O3·2H2O) as green, natural red ochre as red, brown ochre as brown and ivory black or bone black (C+Ca3(PO4)2) and manganese oxides (Mn2O3 and MnO2) as black pigments, in the composition of the Ataturk portrait. Lead white (2PbCO3·Pb(OH)2), calcite (CaCO3), barite (BaSO4), zinc white (ZnO) and titanium white (TiO2) were used as extenders to lighten the colours and/or as for ground level painting. Powder pigment samples, obtained from the paint box of artist, were found to be mixed pigments rather than pure ones.

Vibrational spectroscopic studies of three dimensional host lattices formed by pyrazine bridges between tetracyanonickelate layers

Three dimensional host lattices have been developed by forming bridges with bidentate pyrazine molecules between adjacent tetracyanonickelate polymeric layers of Ni(II) or Cd(II). The Fourier-transform IR and Raman spectra (4000-200 cm−1) of the compounds with the general formula M(pyz)Ni(CN)4, (where M = Ni or Cd) are reported. These host lattices can include benzene molecules but it is found that aniline molecules cannot be included in these structures. They, however, form complexes with the formula M(an)2Ni(CN)4, by replacing pyrazine ligands. A monodentate pyrazine complex of Cd(II) with the formula Cd(pyz)2Ni(CN)4 has also been prepared.

FT-IR and FT-Raman spectroscopic investigations of adsorption of 2,2 '-biquinoline by smectite group clay minerals from Anatolia.

The sorption of 2,2′-biquinoline onto natural and ion-exchanged montmorillonite (Fe-, Co- or Cu-montmorillonite) and saponite from Anatolia have been investigated using FT-IR and FT-Raman Spectrometry. The intercalation of 2,2′-biquinoline within natural and ion-exchanged montmorillonite and saponite has been shown by X-ray diffraction to increase the interlayer spacing. The difference of basal spacing of air-dried clays and biquinoline treated ones shows monolayer arrangement. Raman spectroscopy was particularly useful for investigation of clay-organic interaction. Vibrational spectroscopy indicates that intercalated 2,2′-biquinoline molecules are coordinated to exchangeable cations (directly and indirectly through water bridges) and/or Lewis acid sites or as bidentate ligand.

Adsorption of isoniazid onto sepiolite-palygorskite group of clays: An IR study.

The adsorption of isoniazid (INH) on sepiolite, loughlinite (natural Na-sepiolite) and palygorskite from Anatolia was investigated by FT-IR spectroscopy. Experimental results indicated that INH molecules, adsorbed on sepiolite-palygorskite group of clays, are coordinated to surface hydroxyls by H-bonding interaction through the pyridine ring nitrogen lone pairs. Moreover, some of the adsorbed INH molecules may enter the interior channels of the sepiolite-palygorskite structure and involve H-bonding interaction with zeolitic water. Some intensity and frequency changes in the OH stretching band of surface hydroxyls (Si-OH) of the INH-treated sepiolite and loughlinite were observed. However, this band is found to be less affected by the adsorption of isoniazid in the case of palygorskite, probably because the surface Si-OH groups in palygorskite appear to be less abundant than in sepiolite or loughlinite.

A vibrational spectroscopic study of the adsorption of 4,4′-bipyridyl by sepiolite and smectite group clay minerals from Anatolia (Turkey)

The adsorption of 4,4′-bipyridyl by natural sepiolite and smectite group clay minerals (bentonite, hectorite and saponite) from Anatolia (Turkey) has been studied using vibrational spectroscopy. Investigation of Fourier-transform infrared and Fourier-transform Raman spectra of adsorbed 4,4′-bipyridyl indicate the presence of chemisorbed species. However, any evidence for the generation of anionic species on the surface of the phyllosilicates has not been detected. It is proposed that the adsorbed bipyridyl molecules on sepiolite are centrosymmetric and H-bonded to the surface hydroxyls through both the nitrogen lone pairs as bidentate ligands. The adsorbed bipyridyl molecules on the smectite group clays are coordinated to exchangeable cations both directly and also indirectly through water as monodentate ligands. XRD patterns of the clays studied are also recorded.

FT-IR spectroscopic investigations of benzidine and bipyridyls adsorbed on diatomite from Anatolia

Abstract FT-IR spectra of benzidine (bnz), 2,2′-bipyridyl (2,2′-bpy) and 4-4′-bipyridyl (4-4′-bpy) adsorbed on natural diatomite from Kutahya-Alayunt (Anatolia, Turkey) have been investigated. Vibrational results indicate the presence of chemisorbed species. No physical sorbed species has been detected. Bnz and 2,2′-bpy treated diatomite samples were found to be coloured, whereas 4,4′-bpy treated diatomite was not altered in colour. The formation of cationic (bnz+ and bnz2+) or anionic (2,2′-bpy−) surface species has also been detected in the case of bnz or 2,2′-bpy treated diatomite, respectively.

Structural investigations of transition metal (II) tetracyanonickelate complexes of 3-chloropyridine using Fourier transform-infrared and laser Raman spectroscopy

Abstract The FT-IR and laser-Raman spectra of five new complexes of the formula ML2Ni(CN)4 (where MMn, Fe, Ni, Zn or Cd; L3-chloropyridine) are reported. The complexes are shown to have a structure consisting of two dimensional polymeric layers formed with Ni(CN)4 ions bridged by ML2 cations. For a given series of isomorphous complexes, the effects of metal ligand bond formation on the ligand vibrational modes are examined and the metal-sensitivity sequence of the ligand frequencies is found to be Mn≈Cd

Raman micro-spectroscopic analysis of cultured HCT116 colon cancer cells in the presence of roscovitine

Raman micro-spectroscopic analysis of cultured HCT116 colon cancer cells in the presence of roscovitine, [seliciclib, 2-(1-ethyl-2-hydroxy-ethylamino)-6-benzylamino-9-isopropylpurine], a promising drug candidate in cancer therapy, has been performed for the first time. The aim of this study was to investigate modulations in colon cancer cells induced by roscovitine. Raman spectra of the cultured HCT116 colon cancer cells treated with roscovitine at different concentrations (0, 5, 10, 25 and 50 μM) were recorded in the range 400-1850 cm(-1). It was shown that the second derivative profile of the experimental spectrum gives valuable information about the wavenumbers and band widths of the vibrational modes of cell components, and it eliminates the appearance of false peaks arising from incorrect baseline corrections. In samples containing roscovitine, significant spectral changes were observed in the intensities of characteristic protein and DNA bands, which indicate roscovitine-induced apoptosis. Roscovitine-induced apoptosis was also assessed by flow cytometry analysis, and analysis of propidium iodide staining. We observed some modifications in amide I and III bands, which arise from alterations in the secondary structure of cell proteins caused by the presence of roscovitine.

FT-IR, EDXRF and Gamma-Isotopic Analyses of Ashes from Coal Fired Power Plants of Turkey

Abstract Nine ash samples collected from five coal fired power plants of Turkey have been analysed by FT-IR, EDXRF and γ -isotopic analyses methods. IR spectroscopy together with mineralogical analysis is found to be a useful method for investigating the inorganic chemical composition of the ashes which is an inherently variable material due to differences in the inorganic chemical composition of the source coal and in ash collection. Gamma-isotopic analysis indicated that all samples contained Ra-226, U-238 and Th-232. On the other hand Cs-137 (16.3 pCi/g) was found only in the ash sample collected from the Yatagan coal fired power plant. An ash sample taken from the electro-filter of the Ambarli, a fuel oil fired-power plant of Turkey, was also analysed for comparision and found that it contained least amount of U-238.