Analysis of phosphines functionalized with crown ether groups by NMR and cyclic voltammetry

The compound benzo-3,4-[18-crown-6]-diphenylphosphine was characterized by P-31, C-13 and H-1 NMR in CDCl3 and CD3CN and by cyclic voltammetry in CH2C l2 and CH3CN. The phosphine crown ether was found to be similar to tripheny lphosphine in electrochemical and spectroscopic properties. Addition of M+P F6- (M+ = Li+, Na+, or K+) to the samples resulted in minimal changes in th e observed P-31 spectra but significant differences in the electrochemistry . This suggests that binding a metal cation to the crown ether can be monit ored electrochemically. (C) 2001 Elsevier Science Ltd. All rights reserved.