Adigüzel, Ragip; Tascioglu, Senay

Complexation reactions between water-soluble and -insoluble reactants were shown to occur in aqueous media in the presence of normal or reverse surfactant micelles, in significantly higher yields at lower temperatures compared to those achieved in neat organic solvents. The highest yield enhancement in the complexation of novel water-insoluble bis(2-amino-1,3,4-thiadiazolyl)methane and 1,4-bis(2-amino-1,3,4-thiadiazolyl)benzene ligands with Cu(II) ions was achieved in the sodium bis(2-ethylhexyl)sulfosuccinate (AOT)-heptane-water reverse micellar system at the hydration ratio of 15. The results revealed that AOT normal micelles cause a change in the reaction mechanism together with the enhancement of the complex formation. The observed micellar effects were rationalized on basis of the properties of bulk solvents, surfactants and ligands, considering the solvation and hydration ratios of reverse micelles. The results have proved the dependence of complex yield on the amount and accordingly also on the properties of water in the micellar core, indicating that the yield can be maximized by the optimization of the hydration ratio.

AtıfWoS4·OpenAlex5

İncele

Adiguzel, Ragip; Ergin, Zuhal; Sekerci, Memet; Tascioglu, Senay

In this study, some transition metal complexes of the bis(2-amino-1,3,4-thiadiazolyl)methane (L) derived from the condensation of malonic acid and thiosemicarbazide, have been synthesized and characterized by IR, H-1-NMR spectra, elemental analyses, magnetic susceptibility and thermogravimetry-differential thermal analysis (TGA-DTA). Coordination numbers of monomeric, Ni(II), Zn(II), and Cd(II) complexes and dimeric Cu(II) complex were found to be four, five, six, and five, respectively. According to the elemental analyses and mass spectra data, the following complex formulas were proposed;[Ni-2(L)(SO4)(2)(H2O)(2)]center dot CH3OH center dot 0.5H(2)O, [Cu(L)(SO4)(H2O)](2)DMF center dot 3H(2)O, [Zn(L)NO3 center dot H2O]center dot NO3 center dot DMF, and [Cd(L)(2)(NO3)H2O]NO3 center dot DMF. Ni(II) and Cu(II) complexes were paramagnetic. Ni(II), Cu(II), and Cd(II) complexes were proposed to be tetrahedral/square planar, square pyramidal, and octahedral structure, respectively. Zn(II) complex is five coordinated. The molar conductance data revealed that Zn((II), and Cd(II) complexes were 1:1 electrolytes(ionic). Ni(II), and Cu(II) complexes were non-electrolytes.

AtıfWoS6

İncele