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    Sorption of heavy metal ions by glass beads-immobilized calix[4]arenes derivative
    (MAIK NAUKA/INTERPERIODICA/SPRINGER, 2013) Gubbuk, Ilkay Hilal; Ozkan, Seyda Cigdem; Yilmaz, Aydan
    Glass beads (GB) immobilized, 5,11,17,23-tetra-tert-butyl-25,27-diethoxycarbonylmethoxy-26,28-dihydroxycalix[4]arene (CA) are prepared and used as a new sorbent in sorption study of removal heavy metal ions. A calixarene derivative bonded to amino-functionalized glass beads sorbent was synthesized via a self assembly technique for sorbent of selected heavy metal ions in aqueous. In order to absorb selected heavy metal ions in aqueous, a calixarene derivative bonded to amino-functionalized glass beads sorbent was synthesized via a self assembly technique. The sorbent which is named GB-APTS-CA was characterized using infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), elemental analysis and thermal analysis (TGA/DTG). The influences of some experimental parameters including pH of the sample solution, weight of sorbent, concentration and temperature have been investigated. The sorption data were evaluated using the Langmuir, Freundlich and Dubinin Radushkevich (D-R) isotherm. The obtained maximum sorption capacity for Cu(II), and Pb(II) is 0.06 mmol g(-1) and 0.02 mmol g(-1), respectively. Thermodynamic parameters such as the standard free energy change (Delta Gau <), enthalpy change (Delta Hau <) and entropy change (Delta Sau <) were calculated to determine the nature of sorption process. Thus, GB-APTS-CA is favorable and useful for the removal of Cu(II) and Pb(II) metal ions.
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    Synthesis of new calix[4] arene amide derivatives and investigation of their DNA cleavage activity
    (TAYLOR & FRANCIS LTD, 2014) Ozkan, Seyda Cigdem; Yilmaz, Aydan; Ozmen, Ismail
    This study comprises the synthesis of new p-tert-butylcalix[4]arene with different amide functional groups and summarises an investigation of their DNA cleavage activities. The structural investigations of the synthesised compounds were examined by FTIR, H-1 NMR, C-13 NMR, elemental analysis and FAB-MS techniques. The interaction between these compounds and pBR322 plasmid DNA has been investigated via agarose gel electrophoresis and, according to the results, compounds 5, 7, 8 and 13 exhibit efficient DNA cleavage activity. In the electrophoresis images of 5, 7 and 8, Form IV which is small DNA fragment was observed in addition to supercoiled Form I, open circular Form II and linear Form III.