Author

Wei Xu

Date of Award

1994

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Abstract

This thesis describes the design and the synthesis of novel anion and cation receptors in which sets of transition metal atoms are introduced on the rims of calixarene bowls.;A bowl-shaped calixresorcinarene 1 has been derivatized to incorporate either four phosphonite units to give a phosphonito-cavitand 2 or eight phosphinite units to give a phosphinito-calixresorcinarene 3. These derivatives have been used as multidentate ligands to incorporate transition metals on the upper-rim of the calixresorcinarene bowl. The chlorogold(I) complex of 4, 2(AuCl){dollar}\sb4{dollar} which was characterized by an X-ray structure determination, is shown to contain three AuCl units around the upper rim of the bowl with the fourth AuCl unit folded inside the cavity.;The tetradentate phosphonito-cavitand, 2 has also been used in the synthesis of several tetracopper(I) and tetrasilver(I) complexes. The tetracopper(I) complex 5 and tetrasilver(I) complex, 6 have been shown to act as size-selective hosts for halide inclusion. Iodide is preferred over chloride as guest since it is large enough to coordinate to all four copper atoms in a unique {dollar}\mu\sb4{dollar}-face-bridging bonding mode. This {dollar}\rm Cu\sb4(\mu\sb4{dollar}-I) and a similar {dollar}\rm Ag\sb4(\mu\sb4{dollar}-Cl) bonding mode have been characterized by X-ray structure determinations on suitable anionic complexes. The anion inclusions found for the transition metal rimmed bowl complexes are unique in supramolecular chemistry.;Both the copper and silver complexes, 5 and 6 proved to be powerful and versatile metal cation receptors. The cation inclusions of 5 and 6 are driven by chelating effects of four chloride donors and enhanced by the occluded anion. X-ray analysis on 5{dollar}\sp-.\rm Cs\sp+{dollar} indicated that the two included {dollar}\rm Cs\sp+{dollar} ions were sandwiched by two anions of 5. Similarly, one {dollar}\rm Hg\sp{lcub}2+{rcub}{dollar} ion in 6{dollar}\sp-\sb2\rm Hg\sp{lcub}2+{rcub}{dollar} were also sandwiched by two anions of 6, but the {dollar}\rm Hg\sp{lcub}2+{rcub}{dollar} appeared to be coordinated with the chloride ligands and almost buried inside the cup defined by the four chloride ligands on the rim and the occluded chloride ligand.;Tetra-O-alkyl-calix (4) arenes are shown to act as hosts for the {dollar}\rm Ag\sp+{dollar} ion. The structure of one silver(I) complex has been determined by an X-ray structure analysis. The silver ion is held in the cavity of the calixarene and is weakly coordinated to two arene groups and one methoxy group.

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