The IR spectra data for a series of thirteen rare earth double-deckers M[Pc(SPh)8]2 (M = Y, Ce⋯Lu, except La and Tm) have been collected and detailed characterized. The electronic absorption spectra showed that the Soret and Q bands are blue-shifted, and especially the Q bands at 705–726 nm clearly become stronger along with the decrease of rare earth ion radius. For MIII[Pc(SPh)8]2, the Infrared characteristic absorption peaks for the phthalocyanine anion radical [Pc(SPh)8]− were observed at 1311–1323 cm−1 as the strongest absorption bands, which can be ascribed to the pyrrole stretching. As for the Ce[Pc(SPh)8], the marker absorption bands at 1335 cm−1 was observed. In addition, the typical IR absorption bands of phthalocyanine radical anion [Pc(SPh)8]− move to the high energy as the decrease of rare earth metal ionic radius. These facts suggest that the π-π electron interaction in these double-deckers becomes stronger along with the lanthanide contraction.

•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.

The infrared (IR) spectroscopic data for a series of nine mixed rare earth triple-deckers M2III[TO(OH)PP](Pc)2] [M = La⋯Dy, except Pm, Y and Ho⋯Lu; H2Por = 5-(4-hydroxyphenyl)-10,15,20-tris(4-octyloxyphenyl)porphyrin, Pc = unsubstituted phthalocyanine] with tervalent rare earths have been collected. 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. The absence of Pc2− another marker IR band around 1376 cm−1 demonstrates that the cerium metal ion in the IR spectrum of Ce2III[TO(OH)PP](Pc)2] exists as intermediate valence state between III and IV. The IR spectra of these mixed triple-decker complexes reveal that the frequencies of pyrrole stretching, isoindole breathing, and aza stretchings are decreased sensitive to the rare earth ionic size, and remain basically unchanged along with the lanthanide contraction. These facts indicate that the π–π interactions in these mixed triple-deckers are weaker than those in the double-deckers.Graphical abstractHighlights► The IR spectra of nine triple-deckers have been systematically investigated. ► Most of the IR frequencies are decreased sensitive to the rare earth ionic size. ► The π–π interactions are weaker than those in the double-deckers.

Raman spectroscopic data in the range of 500–1800 cm−1 for a series of nine mixed rare earth triple-deckers M2[TO(OH)PP](Pc)2 [M = La…Dy, except Pm; H2Por = 5-(4-hydroxyphenyl)-10,15,20-tris(4-octyloxyphenyl)porphyrin] have been collected using laser excitation sources emitting at 632.8 nm. Comparison with the Raman spectra of the corresponding bis(phthalocyaninato) and mixed double-decker rare earths reveals that the Raman characteristics of these mixed triple-deckers M2III[TO(OH)PP](Pc)2 are dominated by Pc2− contributions. There is no obvious band that can be assigned to the [TO(OH)PP]2− moiety. 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. For Ce2III-IV[TO(OH)PP](Pc)2, a strong band at 1521 cm−1 with contribution from both pyrrole CC and aza CN stretches as well as the isoindole stretches was the marker Raman band of Pc2−. The Raman spectra of these mixed triple-decker complexes reveal that most of the Raman vibrations derived from pyrrole stretching, isoindole breathing, CH bend and aza stretching are decreased sensitive to the rare earth ionic size, and remain basically unchanged along with the lanthanide contraction. These facts indicate that the π–π interactions in these mixed triple-deckers are weaker than those in the double-deckers.Graphical abstractHighlights► The Raman spectra of nine triple-deckers have been systematically investigated. ► Most of the Raman frequencies are decreased sensitive to the rare earth ionic size. ► The π–π interactions are weaker than those in the double-deckers.

The Raman spectroscopic data in the range 500–1800 cm−1 for a series of 15 rare earth double-deckers with tervalent rare earths MIII[Pc(MeOPhO)8]2 (M = Y, La, …, Lu, except Ce, Pr and Pm), reduced state HPr[Pc(MeOPhO)8]2 and intermediate-valent cerium Ce[Pc(MeOPhO)8]2 have been collected using laser excitation source emitting at 632.8 nm. With excitation at 632.8 nm, which is in close resonance with the main Q absorption band of the phthalocyanine ligand, typical Raman marker bands of the monoanion radical [Pc(MeOPhO)8]− were observed at 1500–1528 cm−1 as very strong bands resulting from the coupling of pyrrole CC and aza CN stretchings. For Ce[Pc(MeOPhO)8]2 and HPr[Pc(MeOPhO)8]2, a very strong band at 1499 cm−1 with contributions from both pyrrole CC and aza CN stretchings and also isoindole stretching was the marker Raman band of [Pc(MeOPhO)8]2−. In addition, the influence of ionic radius of the rare earth metal and substituent species on the Raman scatting characteristics of sandwich-type compounds has also been tentatively studied.

Four novel mixed (porphyrinato)(phthalocyaninato) rare earth double-deckers EuIII(TClPP)[Pc(t-BuPhO2)4] {H2TClPP = tetrakis(4-chlorophenyl)porphyrin, H2[Pc(t-BuPhO2)4] = 1,3,10,12(11,13),19,21(20,22),28,30(29,31)-octa-tert-butyl-tetrakis[1,4]benzodioxino[2,3-b:2′,3′-k:2″,3″-t:2‴,3‴-e1]phthalocyanine}, HEuIII(TClPP)[Pc(α-OC4H9)8] {H2[Pc(α-OC4H9)8] = 1,4,8,11,15,18,22,25-octa-butoxy-phthalocyanine}, EuIII(TClPP)[Pc(MeOPhO)8]{H2[Pc(MeOPhO)8] = 2,3,9,10,16,17,23,24-octakis(4-methoxyphenoxy)phthalocyanine} and EuIII(TClPP)[Pc(PhS)8] {H2[Pc(PhS)8] = 2,3,9,10,16,17,23,24-octakis(benzenesulfenyl)phthalocyanine} have been prepared for the first time by treating Eu(acac)(TClPP) with corresponding metal-free phthalocyanine in refluxing 1,2,4-trichlorobenzene (TCB). Typical IR marker bands of the monoanion radical Pc(t-BuPhO2)4-, Pc(MeOPhO)8- and Pc(PhS)8- show strong bands at 1310, 1319, and 1318 cm−1, and are attributed to pyrrole CC stretchings. The TClPP− IR marker band at ca. 1270–1300 cm−1 was not observed for these compounds. These facts indicate that the hole in these double-deckers is mainly localized at the phthalocyanine ring. The marker IR band for phthalocyanine monoanionradical, Pc(α-OC4H9)8-, appearing at ca. 1312 cm−1 as a medium absorption band was not observed for HEuIII(TClPP)[Pc(α-C4H9)8]. Instead, a significant peak appearing at ca. 1321 cm−1 with weak intensity is assigned to the pyrrole stretching of the phthalocyanine dianion, Pc(α-OC4H9)82-. This suggests that both the phthalocyanine and porphyrin rings exist as dianions in mixed (porphyrinato)(phthalocyaninato) complex, HEuIII(TClPP2-)[Pc(α-OC4H9)82-]. The four complexes were characterized by MS, EA, UV–Vis and IR spectra.Four novel mixed (porphyrinato)(phthalocyaninato) rare earth double-deckers have been prepared for the first time by treating Eu(acac)(TClPP) with corresponding metal-free phthalocyanine in refluxing 1,2,4-trichlorobenzene (TCB). The four complexes were characterized by MS, EA, UV–Vis and IR spectra.