1026861-04-0Relevant articles and documents
Recognition by A New Chiral Dimethyl-substituted Phenanthrolino-18-Crown-6 Diester Ligand of the Enantiomers of Various Organic Ammonium Perchlorates
Wang, Tingmin,Bradshaw, Jerald S.,Huszthy, Peter,Kou, Xiaolan,Dalley, N. Kent,Izatt, Reed M.
, p. 1 - 10 (2007/10/02)
The new chiral dimethyl-substituted phenanthrolino-18-crown-6 diester ligands and (see Figure 1) were prepared through the reactions of 1,10-phenanthroline-2,9-dicarboxylyl dichloride with (S,S)-dimethyl-substituted triethylene glycol and (S,S)-dimethyl-substituted benzotriethylene glycol, respectively.The complexation of (S,S)-3 with the enantiomers of various organic ammonium perchlorates in various solvent systems was studied by 1H nmr spectral techniques and molecular mechanics.The degree of enantiomeric recognition was determined by the difference in the free energy of activation values (ΔΔGC) and the difference in log K values for these interactions.The extensive ? system in the ligand plays an important role for the strong interaction and recognition.The 1H nmr NOESY spectra and molecular mechanics calculations for the interactions of the new ligand with the organic ammonium salts further proved the existence of a ?-? interaction.