The features of cerium coordination chemistry in the complexes with tetra-15-crown-5-phthalocyanine

For the first time, using a method of direct interaction of crownphthalocyanine and cerium(III) acetate in the presence of strong organic base, a sandwich-type double-decker cerium(IV) bis [tetra-(15-crown-5)-phthalocyaninate] [Ce4+(R4Pc2-)(2)](0) (R4Pc2- = [4,5,4',5',4,5,4',5'-tetrakis(1,4,7,10,13-pentaoxapentadecamethylene)-phthalocyaninate-anion]) is synthesized with 60% yield. The composition and structure of the obtained complex are confirmed using spectral methods. UV-vis, IR and H-1 NMR spectroscopy and MALDI-TOF mass-spectrometry were used for characterization of the complex. It has been shown, that a particular feature of cerium ion in the complex with tetra-15-crown-5-phthalocyanine is the stability of oxidation state +4, unlike other lanthanide ions. The Ce(IV) complex has been obtained despite using a Ce(III) salt in synthesis. It has been found that the introduction of crown ether substituents in the phthalocyanine molecule results in a decreased stability of the compound to oxidation in comparison with unsubstituted and tert-butyl substituted cerium phthalocyaninates. Copyright (c) 2006 Society of Porphyrins & Phthalocyanines.