1. Metal complex-containing polysiloxanes as novel coatings for capillary electrophoresis and capillary electrochromatography. 2. Synthesis and characterization of multinuclear metal complexes and their assembly into cage molecules that act as hosts.

摘要

Chapters 1 and 2. Two novel polysiloxane-based polymers containing the metal complex Co(TACN)₂3+, (TACK = 1,4,7-triazacyclononane) have been prepared. Through cross-linking and covalent bonding, the positively charged polymers were coated on fused silica capillary columns and spherical silica particles that were used for capillary electrophoresis (CE) and capillary electrochromatography (CEC), respectively. In both CE and CEC, these coatings exhibited strong, pH-independent, and anodic electroosmotic flow (EOF), and had excellent long-term stability. The lifetimes of these polymer coated silica supports were approximately 2.5 months under continual use. The polymer-coated columns used in CEC generated the highest EOF among all reported CEC packings. Successful separations of aromatic acids were achieved in CE. In CEC, separations of alkylbenzenes (7 min) and basic aromatic compounds (20 min) were achieved with higher resolving power than that obtained using conventional octadecyl silica (ODS) packings. These polymers represent a new class of coatings for CE and CEC that generate strong and pH-independent EOF.; Chapters 3 and 4. A resorcinarene cavitand-based molecule functionalized with four TACN moieties, TACN-res (12), was prepared and used to explore the properties of metal-assembled complexes. The multinuclear Fe(II), Co(III), Ni(II) and Cu(II) complexes of TACN-res were characterized via ESI-MS, NMR, IR and UV. The feasibility of using TACN-res (12) as ligand for a variety of transition metal ions suggests the possibility of assembling supramolecular structures and networks and preparing materials with unique properties based on this approach.; Besides TACN, iminodiacetic acid was also able to coordinate to metal ions. In the case of iminodiacetic acid resorcinarene 1, cobalt(II) ions brought together two molecules of 1 to form a hydrophobic cavity. This metal-assembled cage Co₄1₂ 8− could encapsulate both water-miscible and water-immiscible organic molecules. In general, the trapping of organic molecules occurred while the cage was being assembled; however, guest penetration studies showed that closed cage could also trap organic molecules. By heating the host-guest complex Co₄1₂8−· guest, some guest molecules were released. Proton NMR experiments not only demonstrated the encapsulation properties of Co₄1 ₂8−, but also helped to monitor guest penetration into the closed cage molecules Co₄1₂8− ·6H₂O, as well as the guest releasing process from Co41₂8−· guest.