Synthesis and characterization of new mixed rare earth triple-decker complexes with A3B type [5-(4-hydroxyphenyl)-10,15,20-tris-(4-octyloxyphenyl)porphyrinato] and phthalocyaninato ligands

• Nine new mixed rare earth triple-decker complexes M2[TO(OH)PP](Pc)2 have been prepared.
• The origin of the electronic absorptions of these triple-decker complexes was tentatively revealed.
• The IR and Raman spectra of M2[TO(OH)PP](Pc)2] were first systematically, investigated.
• The π–π interactions are weaker than those in the double-deckers.

Nine new mixed rare earth triple-decker complexes M2[TO(OH)PP](Pc)2 [M = La…Dy, except Pm; H2Por = 5-(4-hydroxyphenyl)-10,15,20-tris(4-octyloxyphenyl)porphyrin] have been prepared by treating M(acac)[TO(OH)PP] with corresponding homoleptic unsubstituted bis(phthalocyaninato) rare earth complexes M(Pc)2 in refluxing 1,2,4-trichlorobenzene (TCB). The origin of the electronic absorptions of these triple-decker complexes was tentatively revealed. For M2III[TO(OH)PP](Pc)2], typical IR marker bands for the unsubstituted phthalocyanine dianion Pc2− are strong bands at 1327–1329 cm−1, and a weak band around 1370–1383 cm−1. They can be assigned to pyrrole CC stretchings. Under excitation at 632.8 nm, typical Raman marker bands of the phthalocyanine dianions Pc2− were observed at 1514–1526 cm−1 as medium band, resulting from the coupling of pyrrole CC and aza CN stretchings. The IR and Raman spectra for Ce2[TO(OH)PP](Pc)2 are very slightly different from those of their other rare earth(III) counterparts. The nine complexes were also characterized by EA, MS and UV–vis spectra.