Complexes of some crown ethers with Hg(II) chloride, bromide, iodide and cyanide

Metal complexes of some mercuric salts (HgCl2, HgBr2, HgI2 and Hg(CN)(2)) w ith crown ethers(DB18C6, DC18C6, DBP18C6, DB24C8) have been prepared. Two t ypes of complexes containing 1:1 and 2:1 metal to ligand ratios were prepar ed and characterized on the basis of elemental analyses, molar conductance, spectral (IR, UV-Visible, H-1 NMR, mass) measurements and thermal analysis (TGA, DTA). The formation constants (K-f) and the free energy changes (Del ta G(f)) of Hg2+ and some Cu2+ complexes were calculated using the continuo us variation method. Also, the stability of the Hg2+ complexes were determi ned on the basis of the shifts of the protons of the -CH2-O-CH2- and Ar-O-C H2 groups. Moreover, the strength of the bond between Hg2+ ion and the crow n ethers is determined using the shifts of the C-O (ethylenic) and C-O (phe nolic) groups of the crown ethers. A study of the thermal properties of the Hg(II) complexes has also been carried out.