A novel approach to heteroleptic heteronuclear rare earth metal(III) trisphthalocyaninates was proposed with the complexes [(15C5)(4)Pc]M*[(15C5)(4)Pc]M(Pc) as examples (15C5 is 15-crown-5, Pc2- is the phthalocyaninate dianion, and M* not equal M = Yb and Y). Unsubstituted lanthanum bisphthalocyaninate, La(Pc)(2), was used for the first time as a Pc2- donor in the synthesis of such complexes. This substantially increased the yields of the target heteronuclear complexes over the previous literature data.