Chiral lipophilic ligands. 2. Cu(II)-Mediated transport of α-amino acids across a bulk chloroform membrane

摘要: Abstract A number of achiral (1 – 4) and chiral (5 10) 1,2-diamino ethane derivatives bearing on one or both nitrogen atoms long paraffinic chains have been synthesized successfully tested as carriers for the transport Cu(II) α-amino acids across a bulk chloroform membrane from buffered (pH=5.5) source phase to receiving solution EDTA. This, being highly hydrophilic ligand with an affinity several order magnitude larger than that carrier, allows effective “up-hill” co-transport ions amino acids. The results indicate occurs via formation ternary complex comprising Cu(II), lipophilic diamine, acid. lipophilicity acid is main factor affecting rate using same other hand, best carrier having constant close transported. apparently governed by release metal ion organic phase. enantioselectivities observed in natural employing ligands are generally modest; cases, enantioselectivity ratios (the initial rates faster enantiomer relative slower) slightly higher 2. appears depend more thermodynamic rather kinetic factors.