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Two novel polysiloxanes containing the metal complex, Co(TACN)23+ (TACN=1,4,7-triazacyclononane) were used as coatings for capillary electrophoresis (CE) and capillary electrochromatography (CEC). Through crosslinking and covalent bonding, the positively charged polymers were bonded to silica supports. In both CE and CEC, these coatings exhibited strong, pH-independent, and anodic electroosmotic flow (EOF), and had excellent long-term stability. Successful separations of aromatic acids were achieved in CE. In CEC, separation of alkylbenzenes (7 min) and basic compounds (20 min) was achieved with higher resolving power than conventional octadecyl silica packings. These polymers represent a new class of coatings for CE and CEC that generate pH-independent EOF. [ABSTRACT FROM AUTHOR]

Two novel polysiloxane-based polymers, which contain metal complexes, have been prepared. To prepare the Co(TACN)23+ (TACN=1,4,7-triazacyclononane) based polymers, an orthoamide derivative of TACN was added to bromobutane-substituted methylpolysiloxane and hydrolyzed with base. Co(II) was then coordinated to the TACN, followed by cobalt oxidation to make polymer A or followed by N-octyl TACN coordination and cobalt oxidation to make polymer B. In both materials, TACN forms thermodynamically and kinetically stable Co(TACN)23+ complexes in which the six coordination sites of the Co(III) are occupied by nitrogens from the TACN. The polymers were coated on fused-silica capillary columns and spherical silica particles, which were used for capillary electrophoresis and capillary electrochromatography, respectively. The open and packed columns showed strong and pH-independent reversed electroosmotic flow. [Copyright &y& Elsevier]