Yüksel Tufan

Immobilization of invertase attached to a granular dimer acid-co-alkyl polyamine

Abstract Invertase was immobilized onto the granular dimer acid-co-alkyl polyamine after activation with carbodiimide. The Km value for immobilized enzyme (53.6 mM) was much greater than that of the free enzyme (20.6 mM). Vmax values were 6.44×10−5 mol dm−3 min−1 and 5.45×10−5 mol dm−3 min−1 for free and bound, respectively. The optimal pH values for free and covalently bonded enzymes were 4.56 and 5.50, respectively. The optimum temperature for both free and covalent invertase was 55°C. The enzyme activities, after storage for 1 month, were found to be 21.0 and 99.0% of the initial activity values for free and covalently bonded, respectively. The immobilized enzyme that was used 50 times in 5 days in repeated batch experiments showed 100% of its original activity.

Vibrational spectroscopic investigations of M(Imidazole)2Ni(CN)4·2C6H12 clathrates

Four new clathrates of the formula M(Im)2Ni(CN)4·2·Dioxane (where M = Co, Ni, Cu, Cd; Im = Imidazole) have been prepared in powder form and their FT-IR and laser-Raman spectra are reported for the first time. These clathrates are analogues to the previously reported classical Hofmann type clathrates except for the copper clathrate. The Cu clathrate has different spectral features in comparison with its analogues due to the Jahn-Teller effect.

Infrared Spectroscopic Study of Bis[1,2-bis(4-Pyridyl)ethane]cadmium(II) Tetracyanonickelate(II)-m-Xylene (1/2) Clathrate and Its Host Structure

Cd[1,2-bis-(4-pyridyl)ethane]2Ni(CN)4-m-xylene(1/2) clathrate and its host structure were prepared and characterized by chemical analysis and infrared spectroscopy. Vibrational assignments are proposed for the bands of the host lattice and guest molecules.

Synthesis and Characterization of Novel Methacrylates Derived from Morpholine and Pyrrolidine: The Determination of Kinetic Parameters with Thermogravimetric Analysis

Abstract The synthesis of two new methacrylate esters containing morpholine and pyrrolidine group are described. The monomers produced from the reaction of corresponding morpholino chloroacetamide and pyrrolidino chloroacetamide with sodium methacrylate were polymerized in DMSO solution at 65°C using AIBN as an initiator. The monomers and their polymers were characterized by Fourier transform infrared (FTIR), 1H‐ and 13C‐NMR spectroscopy. The glass transition temperature of the polymers were investigated by DSC and thermal decomposition activation energies were calculated by the Ozawa method using the SETARAM Labsys thermogravimetric analysis (TGA) thermobalance, respectively. By using gel permeation chromatography, weight average (M¯w) and number average (M¯n) molecular weights and polidispersity indices of the polymers were determined.

SYNTHESIS AND SPECTROSCOPIC STUDIES OF METAL (II) TETRACYANONICKELATE COMPLEXES WITH 1,3-THIAZOLIDINE-2-THIONE

Abstract Two new Hofmann-type complexes, M (1,3-thiazolidine-2-thione)2 Ni(CN)4 (where M = Ni and Cd), were synthesized and characterized by elemental analysis, magnetic susceptibility data, IR and Raman Spectroscopy. Their structure consist of planar infinite polymeric layers of {M-NI(CN)4}∞. 1,3-thiazolidine-2-thione coordinated to M atom above and below this layers is monodentate and S-bonded in these complexes.

Vibrational Spectroscopic Study of [1,2-bis(4-pyridyl)ethane]metal(II) Tetracyanonickelate(II). 2 m-Xylene Clathrates

Four new Hofmann-type clathrates of the form M(bpa)2Ni(CN)4· 2m-xylene (M = Mn , Fe , Co and Ni; bpa = 1,2-bis(4-pyridyl)ethane) have been synthesized and characterized by vibrational spectroscopy. The M(bpa)2Ni(CN)4 (M = Fe and Co) host structure is similar to the classical Hofmann-type host framework composed of layers of a two dimensional catena-metal tetra-μ-cyanonickelate(II) network, but in M(bpa)2Ni(CN)4 (M = Mn and Ni), the Ni(CN)4 moiety behaves as a bidentate –[NC-Ni(CN)2-CN–]– unit in the host framework.