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Three novel mixed (phthalocyaninato)(porphyrinato) yttrium double-decker complexes appended with one metal-free porphyrin chromophore at the para, meta, and ortho position, respectively, of one meso-phenyl group of the porphyrin ligand in the double-decker unit through ester linkage, 3−5, have been designed, synthesized, and spectroscopically characterized. The photophysical properties of these three isomeric tetrapyrrole triads were comparatively investigated along with the model compounds metal-free tetrakis(4-butyl)porphyrin H2TBPP (1) and mixed [1,4,8,11,15,18,22,25-octakis(butyloxyl)phthalocyaninato][tetrakis(4-butyl)porphyrinato] yttrium double-decker complex HY[Pc(α-OC4H9)8](TBPP) (2) by steady-state and transient spectroscopic methods. The fluorescence of the metal-free porphyrin moiety attached through ester linkage at the meta and ortho position of one meso-phenyl group of porphyrin ligand in the double-decker unit in triads 4and 5is effectively quenched by the double-decker unit, which takes place in several hundred femtoseconds. However, the fluorescence of the metal-free porphyrin moiety attached at the para position of one meso-phenyl group of porphyrin ligand in the double-decker unit in triad 3is only partially quenched, clearly revealing the effect of the position of porphyrin-substituent on the photophysical properties of the triads. Furthermore, the molecular structures of 3−5were simulated using density functional theory calculations. It was found that the relative orientation between the metal-free porphyrin moiety and the double-decker unit for compound 3is crossed, while those for compounds 4and 5are open- and closed-shellfish-like, respectively, which is suggested to be responsible for their different intramolecular fluorescent quenching efficiency. [ABSTRACT FROM AUTHOR]

A series of amphiphilic heteroleptic tris(phthalocyaninato) europium complexes with hydrophilic poly(oxyethylene) heads and hydrophobic alkoxy tails {Pc[(OC2H4)2OCH3]8}Eu{Pc[(OC2H4)2OCH3]8}Eu{Pc(OCnH2n+1)8] (n = 6, 8, 10, 12) (1-4) were designed and prepared from the reaction between homoleptic bis(phthalocyaninato) europium compound {Pc[(OC2H4)2OCH3]8}Eu{ Pc[(OC2H4)2OCH3]8} and metal-free 2,3,9,10,16,17,23,24-octakis(alkoxy)- phthalocyanine H2Pc(OCnH2n+1)8 (n = 6, 8, 10,12) in the presence of Eu(acac)3·H2O (Hacac = acetylacetone) in boiling 1,2,4-trichlorobenzene (TCB). These novel sandwich triple-decker complexes have been characterized by a wide range of spectroscopic methods and have been electrochemically studied. With the help of the Langmuir- Blodgett (LB) technique, these typical amphiphilic triple-decker complexes have been fabricated into organic field effect transistors (OFET) with an unusual bottom contact configuration. The devices display good OFET performance with the carrier mobility for holes in the direction parallel to the aromatic phthalocyanine rings, which shows dependence on the length of the hydrophobic alkoxy side chains, decreasing from 0.46 for 1 to 0.014 cm² V-1 s-1 for 4 along with the increase in the carbon number in the hydrophobic alkoxy side chains. [ABSTRACT FROM AUTHOR]