THE INFLUENCE OF SIDE-CHAINS ON THE COMPLEXATION OF CATIONS BY CROWNS. SYNTHESIS AND Cu(II) COMPLEXATION OF N,N'-DIARYL-DIAZA-18-CROWN-6

Article abstract of DOI:10.1016/S0040-4020(01)91109-3

Various N,N'-diaryl derivatives of 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane were synthesized. 7,16-diphenyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane had only a low affinity for cations.On the contrary, diamide derivatives of 7,16-di<(2-amino)phenyl>-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane were deprotonated by Cu(II) and formed stable chelates.Spectral data suggest that monodeprotonation gives dissymmetric 1:1-complexes and dideprotonation gives symmetric 1:1-complexes.