Controlling the Nature of Mixed (Phthalocyaninato)(porphyrinato) Rare-Earth(III) Double-Decker Complexes: The Effects of Nonperipheral Alkoxy Substitution of the Phthalocyanine Ligand

• Published in: Chemistry : a European journal 2006-02, Vol.12 (5), p.1475-1485
• Main Authors: Wang, Rongming, Li, Renjie, Li, Yong, Zhang, Xianxi, Zhu, Peihua, Lo, Pui-Chi, Ng, Dennis K. P., Pan, Na, Ma, Changqin, Kobayashi, Nagao, Jiang, Jianzhuang
• Format: Article
• Language: English
• Subjects: phthalocyanines; porphyrinoids; rare-earth elements; sandwich complexes; substitution effect
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200500733

The half‐sandwich rare‐earth complexes [MIII(acac)(TClPP)] (M=Sm, Eu, Y; TClPP=meso‐tetrakis(4‐chlorophenyl)porphyrinate; acac=acetylacetonate), generated in situ from [M(acac)3]⋅n H2O and H2(TClPP), were treated with 1,8,15,22‐tetrakis(3‐pentyloxy)phthalocyanine [H2{Pc(α‐OC5H11)4}] (Pc=phthalocyaninate) under reflux in n‐octanol to yield both the neutral nonprotonated and protonated (phthalocyaninato)(porphyrinato) rare‐earth double‐decker complexes, [MIII{Pc(α‐OC5H11)4}(TClPP)] (1–3) and [MIIIH{Pc(α‐OC5H11)4}(TClPP)] (4–6), respectively. In contrast, reaction of [YIII(acac)(TClPP)] with 1,4,8,11,15,18,22,25‐octakis(1‐butyloxy)phthalocyanine [H2Pc(α‐OC4H9)8] gave only the protonated double‐decker complex [YIIIH{Pc(α‐OC4H9)8}(TClPP)] (7). These observations clearly show the importance of the number and positions of substituents on the phthalocyanine ligand in controlling the nature of the (phthalocyaninato)(porphyrinato) rare‐earth double‐deckers obtained. In particular, α‐alkoxylation of the phthalocyanine ligand is found to stabilize the protonated form, a fact supported by molecular‐orbital calculations. A combination of mass spectrometry, NMR, UV‐visible, near‐IR, MCD, and IR spectroscopy, and X‐ray diffraction analyses, facilitated the differentiation of the newly prepared neutral nonprotonated and protonated double‐decker complexes. The crystal structure of the protonated form has been determined for the first time. Controlling the nature of heteroleptic rare‐earth(III) sandwich complexes. An in‐depth study of the influence of alkoxy‐substitution of the phthalocyanine ligand on the formation of (phthalocyaninato)(porphyrinato) rare‐earth(III) double‐decker complexes. The protonated and nonprotonated forms are indicated in the scheme.