Benzo-crown ether, and catechol functionalized salicylideneimine complexes and their transport properties. A new class of supramolecular complexes.

The focus of this dissertation is the synthesis and characterization of two new classes of supermolecules: the catechol functionalized salphen (salcat) and the crown ether functionalized salphen (salcrown). The ability of these complexes to transport biologically important molecules across bulk liquid membranes represents the culmination of these compounds into useful materials. Detailed synthesis and characterization of the salcat ligand and its complexes with several first row transition metals (Mn$\sp{+3}$, Fe$\sp{+2}$, Co$\sp{+2}$, Ni$\sp{+2}$, Cu$\sp{+2}$) in the salicylidene cavity are presented. Complexes at the catechol site of the salcat ligand with several transition metals (Fe$\sp{+3}$, Co$\sp{+2}$, Ni$\sp{+2}$, Cu$\sp{+2}$), the vanadyl group (VO$\sp{+2}$) and oxo-thiomolybdate clusters ( (Mo$\sb2$O$\sb2$S$\sb2\rbrack\sp{+2}$, (Mo$\sb2$O$\sb2$S$\sb2$(S$\sb2$))) are also discussed. The synthesis and characterization of the sal-18-crown-6, bis-sal-18-crown-6, and bis-sal-24-crown-8 ligands, along with their complexes with several first row transition elements (Mn$\sp{+3}$, Fe$\sp{+3}$, Co$\sp{+2}$, Ni$\sp{+2}$, Cu$\sp{+2}$) are discussed. Many of these complexes are then further complexed with 1A metals (K$\sp+$, Cs$\sp+$) at the crown ether site. All of these molecules were utilized for the construction of increasingly more complex supramolecular structures, several of which have been characterized by crystallography. Such molecular motifs are actively sought for use as catalysts, and recognition agents because of their precise arrangement of structural and chemical features. This arrangement of features directly affects the properties of the supramolecular complex as a whole and enhances its specificity as a host for a particular guest or substrate. Facilitated transport experiments were conducted to explore the host-guest properties of these supramolecular complexes. The use of these new complexes to facilitate transport in bulk liquid membranes was examined with tryptophan, serotonin and dopamine. The salcrowns, in particular, are excellent facilitators for transport of tryptophan and serotonin. Transport was also examined in the presence of varying concentrations of the alkali metal ions, K$\sp+$ and Cs$\sp+.$ Finally, for the cationic manganese complex, the transport properties were examined with the anions Cl$\sp-$ and I$\sp-.$ A detailed investigation of the importance of the crown ether vs. the supramolecular complex, vs. the salphen complex alone or mixed with benzo-crown were examined. This investigation resulted in the conclusion that the supramolecular complex is the optimal arrangement for facilitated transport of either tryptophan or serotonin. 6-Aminohexanoic acid and 8-aminooctanoic acid were examined as potential ditopic guests though only limited transport of these materials was observed.Ph.D.BiochemistryInorganic chemistryPharmacy sciencesPure SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/131523/2/9909978.pd