X-ray difraction study of a metal-cyclic polyether complex and thermodynamics of proton ionization and metal-ligand interactions in aqueous solution
The crystal structure of the barium thiocyanate complex of isomer A of the cyclic polyether dicyclo-hexyl-18-crown-6 has been determined by X-ray difraction techniques. It has been found that isomer A is in the cis-syn-cis conformation. Dicyclohexyl-18-crown-6 is prepared by hydrogenation of dibenzo-18-crown-6. Five isomers are possible as a result of this hydrogenation but only two have been isolated. ^1H and ^13C NMR results lead to trans and cis hydrogenation assignments, respectively. This study resolved the disagreement regarding the conformation differences between isomers. Log K, ΔH°, and ΔS° values for the hydrolysis and SO_4^= ion interaction of Al^3+ and Fe^3+ ions have been determined using an isothermal calorimetric titration procedure. The reactions were carried out in aqueous solution at 25° and ionic strengths of 0, 1.0, and 3.0, and also at 50° at an ionic strength of zero. Values of log K, ΔH°, and ΔS° valid at zero ionic strength and 10, 25 and 40° are reported for the interaction of dipicolinate ion with H^+, Mg^2+, Ca^2+, and Sr^2+ ions and for proton ionization from several cycloalkane-carboxylic acids and mono-substituted protonated pyridines.
College and Department
Chemistry and Biochemistry
BYU ScholarsArchive Citation
Smith, Don Edward, "X-ray difraction study of a metal-cyclic polyether complex and thermodynamics of proton ionization and metal-ligand interactions in aqueous solution" (1972). Theses and Dissertations. 8355.