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] [ Ce ⁴⁺( R ₄ Pc ²⁻)₂]⁰ ( R ₄ Pc ²⁻ = [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 ¹ H 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-butylsubstituted cerium phthalocyaninates.