Acyclic oligoamides

In this study, the target molecules are acyclic oligoamides with the generalized structure shown in Figure 2. Within this structure, constituents R, X, Y, and Z, as well as the chain length, may be systematically varied. In addition, incorporation of appropriate substituents into X and Y may be utilized to enhance the propensity for formation of a pseudocyclic cavity. Effectiveness of these new ionophores as metal ion carriers can be evaluated by proton-driven cation transport from a weakly acidic aqueous solution through a liquid membrane into a more acidic aqueous solution (see Figure 3). 

Acyclic oligoamides, 167-168,170/ Advancing front model, description, 116 Alkali metal cation facilitated transport through supported liquid membranes with fatty acids electrogenic processes, 79-81 electroneutral transport, 76-80 experimental description, 77 kinetics, 81-85... 

Several types of acyclic amides have been synthesized and evaluated as carriers for metal ion transport across liquid membranes. The abilities of oligoamides containing 8-quinolyl groups to transport heavy metal ions, such as copper(II), mercury(n), silver(I), etc., across bulk chloroform membranes are assessed. Among the different types of amides, malonamide and glutaramide derivatives are found to exhibit high selectivity for copper(II) transport and different methionine derivatives for mercury(II) and for silver(I) transport. The relationship between the structure of the ionophore and its transport behavior is discussed. 

---