| A series of boron acids, quaternary ammonium salts, and ruthenium (II) bipyridyl metallocenes were evaluated as organic liquid membrane transport carriers for saccharides and nucleoside phosphates. A mixed-ligand borate strategy was used to extract and transport various p-nitrophenyl ;A supported liquid membrane (SLM) containing a lipophilic boronic acid was found to be selectively permeable to fructose over glucose. Fructose transport was accomplished via a proposed transient formation of a reversible trigonal boronate ester. Addition of immobilized glucose isomerase to a source compartment comprised exclusively of glucose produced a receiving phase which was 70% fructose. In an attempt to increase the fructose transport selectivity, several lipophilic diboronic acid carriers were designed, synthesized, and evaluated in SLMs. They exhibited no enhancements in saccharide transport compared to the analogous monoboronic acids.;Plasticized liquid membranes (PLMs) containing quaternary ammonium salts were found to be remarkably permeable to saccharides. Moreover, the membranes were highly stable which is a significant advantage over other liquid membrane configurations. A number of mechanistic investigations indicated that saccharide transport is due to a fixed-site jumping mechanism. This represents the first example of saccharide transport through liquid membranes by a fixed-site jumping mechanism.;A mixture of boronic acid and bis(quaternary ammonium) dication was found to mediate the transport of ribonucleoside phosphates through BLMs and SLMs. This carrier mixture exhibited selectivity for... |
