Synthesis and characterization of novel oligomeric host systems and their complexation abilities

CHED 1243

Allix Sanders, ams012@lvc.edu, Kenneth Houser, krh002@lvc.edu, and Marc A. Harris, harris@lvc.edu. Department of Chemistry, Lebanon Valley College, 101 N. College Ave, 402 N-G Center, Annville, PA 17003
Two novel ethylene oxide bridged bipyridine oliogmers have been synthesized. These systems contain a pyridyl nitrogen donor atom and either four (1) or six (2) oxygen donor atoms. Extraction efficiencies and selectivities of the oligomeric systems for alkali picrates (Na+, K+, Cs+) were probed using a liquid-liquid ion extraction study. Both ‘open-chain' oliogmers displayed unexpectedly high extraction efficiencies and selectivities for varying guest ions (1 – Na>K>Cs; 2 – Cs>K>Na). These oligomeric systems follow the ‘same-fit' concept that has been previously reported for macrocyclic analogues. These oligomeric complexes were characterized using MALDI-TOF mass spectrometry and 1H NMR spectroscopy. A Job's plot was obtained using a UV-visible spectral analysis of the complexes, which displayed the expected 1:1 (oligomer to ion) stoichiometry in the solution state. Upon metallation of the peripheral bipyridine units binding efficiencies and selectivities of these metallated hosts are expected to change.