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A novel mixed (phthalocyaninato)(porphyrinato) yttrium(III) double-decker complex with a C-60 chromophore covalently linked at the porphyrin ligand by phenyl ether linkage has been designed and synthesized. The photophysical properties of this novel dyad containing the C-60 and mixed (phthalocyaninato)(porphyrinato) yttrium(III) double-decker components were investigated by steady-state and transient spectroscopic methods. Comparative studies over the electronic absorption spectra document that there is no considerable electronic interaction between the C-60 and mixed (phthalocyaninato)(porphyrinato) yttrium(III) double-decker components in the ground state. Time-resolved absorption spectra of this dyad reveal a photoinduced electron transfer from the (HY[Pc(alpha-OC4H9)(8)](Por)) moiety to the C-60 moiety upon irradiation at 400 nm, which excites both of the components, resulting in a charge-separated state with a lifetime longer than 1 ns. (C) 2013 Elsevier Ltd. All rights reserved.

Treatment of sandwich-type mixed (phthalocyaninato)(porphyrinato) metal complex [HEu III {Pc(α-3-OC 5 H 11 ) 4 }{TriBPP(NH 2 )}] ( 3 ) [Pc(α-3-OC 5 H 11 ) 4 = 1,8,15,22-tetrakis(3-pentyloxy)-phthalocyaninate, TriBPP(NH 2 ) = 5,10,15-tris(4- tert -butylphenyl)-20-(4-aminophenyl)porphyrinate] with N- n -butyl-1,6,7,12-tetra(4- tert -butylphenoxyl)perylene-3,4-dicarboxylate anhydride-9,10-dicarboxylate imide ( 2 ) in the presence of imidazole in toluene afforded the novel perylene diimide-appended mixed (phthalocyaninato)(porphyrinato) europium(III) double-decker complex ( 5 ). Porphyrin–PDI dyad 4 was also obtained by similar method. The electronic absorption spectroscopic and electrochemical properties of PDI-appended double-decker 5 and the model compounds 2 , 3 , and 4 were studied, the results indicated that there was no considerable ground-state interaction between the double-decker unit and the PDI unit in 5 . The fluorescence measurements revealed that the emission of PDI unit was effectively quenched by the double-decker unit, suggesting remarkable intramolecular interaction in 5 under excited state.

Effects of the meso-substituents and central metals on the molecular structures, atomic charges, molecular orbital energy gaps, electronic absorption spectra, and infrared (IR) spectra of 12 meso-tetrasubstituted porphyrin complexes including metal-free porphyrins H2P or (Por = TPP, TFPP, TClPP, TPyP) (1–4) and their metal complexes MPor (M = Mg, Zn; Por = TPP, TFPP, TClPP, TPyP) (5–12) [TPP = meso-tetrakis(phenyl)porphyrinate; TFPP = meso-tetrakis(4-fluorophenyl)porphyrinate; TClPP = meso-tetrakis(4-chlorophenyl)porphyrinate; TPyP = meso-tetrakis(4-pyridyl) porphyrinate] are systematically studied by density functional theory calculations at the B3LYP/6-31G(d) level. Good consistency was found between the calculated molecular structures and the experimental X-ray crystallography ones for 1, 3, and 4, and between the simulated electronic absorption and IR spectra and the experimental ones for 1 and 4. The calculation results reveal that introducing substituents at the meso positions of porphyrin induces increasing change in the molecular structures, atomic charges distribution, HOMO and LUMO energy, electronic absorption spectra, and IR spectra along with the increase in the electron-withdrawing ability of substituents in the order of phenyl, 4-fluorophenyl, 4-chlorophenyl, and pyridyl group. Furthermore, the central metal in porphyrins displays much significant influence on the structure and spectroscopic properties of meso-substituted porphyrin complexes. The electronic absorption and IR spectra of 1–12 are compared and assigned in detail. The present work should be not only helpful towards understanding the meso-substitutional and central metallic effects on the structure and spectroscopic properties of meso-substituted porphyrin complexes, but also useful in correctly assigning electronic absorption and IR spectra for porphyrin complexes.

Third-order nonlinear optical properties of three isomeric tetrapyrrole triads, i.e. mixed (porphyrinato)(phthalocyaninato) 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, were comparatively investigated along with the model compounds metal free meso-tetrakis(4- tert -butylphenyl) porphyrin H 2 TBPP (1) and mixed [meso-tetrakis(4- tert -butylphenyl)porphyrinato] [1,4,8,11,15,18,22,25-octakis(butyloxyl)phthalocyaninato] yttrium double-decker complex Y III H(TBPP) [Pc(α-OC 4 H 9 ) 8 ] (2) by using Z-scan technique with the fundamental (800 nm) laser emission from a Ti:sapphire femtosecond laser system. Strong reverse saturable absorption (RSA) properties of complexes 2-5 were observed. Interestingly, under highly intense irradiation, an RSA-SA-RSA-SA-RSA switch behavior was evolved in the tight focal intensity regime on the Z-scan profiles of complexes 3-5. Under the laser irradiation with focal intensity of 7.48-8.39 GW.cm -2 , the triads 3 and 4 with the metal free porphyrin chromophore appended at the para or meta positions of the meso-phenyl group of the porphyrin ligand in the double-decker unit retained a characteristic response of RSA. In contrast, the triad 5 with the metal free porphyrin chromophore appended at the ortho position has already shown a trend of SA peaks at the same intensity range, revealing the effect of the position of porphyrin-substituent on the nonlinear optical properties of the triads.