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ABSTRACT: Gold standard: A bis(Au(III) ) complex containing the title compound was prepared and characterized (see scheme; DDQ=2,3-dichloro-5,6-dicyano-1,4-benzoquinone, Tf=trifluoromethanesulfonyl). Owing to the effective conjugative network over the flat and elongated rectangular molecular frame, this complex displays a remarkably red-shifted and sharp Q-band-like band at 1467 nm, multiple reversible redox potentials, and a large TPA cross-section value.
Angewandte Chemie International Edition 08/2012; 51(39):9856-9. · 13.45 Impact Factor
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ABSTRACT: Newcomers: meso-Arylamino- and meso-alkylaminosubporphyrins have been synthesized by the Pd-catalyzed aminations of meso-bromosubporphyrin 1 as the first example of subporphyrins containing heteroatom substituents at the meso-position. The X-ray structural analyses have revealed significant structural distortions of meso-aminosubporphyrins 2 due to the effective electronic interaction (see scheme).
Chemistry 06/2012; 18(29):8929-33. · 5.93 Impact Factor
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ABSTRACT: Hexakis(pentafluorophenyl)-substituted meso-meso-linked Zn(II)-diporphyrin (9), which was prepared by the acid-catalyzed cross-condensation of 1,1,2,2-tetrapyrroethane (5) with dipyrromethane dicarbinol (6), was converted into meso-meso,β-β,β-β triply linked Zn(II)-diporphyrin 3 by oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) and Sc(OTf)(3). Beside the red-shifted absorption spectrum and split first oxidation potential that are common to the triply-linked Zn(II)-diporphyrins, diporphyrin 3 exhibited considerably improved chemical stability owing to a lowered HOMO and good solubility in common organic solvents. The two-photon absorption (TPA) cross-section and S(1)-state lifetime of compound 3 were 1700 GM and 3.3 ps, respectively.
Chemistry - An Asian Journal 05/2012; 7(8):1811-6. · 4.50 Impact Factor
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ABSTRACT: Rational synthesis of A(2)B-type meso-arylsubporphyrins has been accomplished by the condensation of triethylamine-tri-N-tripyrromethene-borane with acid chlorides. These subporphyrins are useful for evaluations of the intrinsic substituent effects and the influences of substitution patterns, A(3)-type versus A(2)B-type substitution.
Organic Letters 05/2012; 14(11):2694-7. · 5.86 Impact Factor
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ABSTRACT: Direct meso-alkynylation of β,β'-dipyridylporphyrin with various alkynyllithium reagents has been achieved, in which the β,β'-dipyridyl groups play an important role in facilitating the nucleophilic addition of the reagents through double coordination. This method enabled the synthesis of a meso-ethynylene-bridged diporphyrin.
Organic Letters 05/2012; 14(11):2778-81. · 5.86 Impact Factor
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ABSTRACT: A meso-free subporphyrin was prepared and quantitatively converted into meso-brominated subporphyrin, which is an effective precursor for the facile installation of substituents at the meso position. The meso-(4-amino)phenylethynyl subporphyrins (see picture; N blue, O red, Br orange, F pale green, B dark green) and a butadiyne-bridged dimer have split Soret-like bands and red-shifted and intensified fluorescence.
Angewandte Chemie International Edition 04/2012; 51(23):5593-7. · 13.45 Impact Factor
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ABSTRACT: A doubly 2,6-pyridylene-bridged porphyrin-perylene-porphyrin triad was synthesized via Suzuki-Miyaura cross coupling reaction, which captures a tetrakis(3-pyridyl)porphyrin guest in a 2 : 1 manner to form a supramolecular complex that undergoes photo-induced electron transfer.
Chemical Communications 03/2012; 48(36):4317-9. · 6.17 Impact Factor
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ABSTRACT: A good catch: The oxidation of a phenylethynyl Pt(II) pincer complex with iodine led to formal reductive elimination but without the liberation of Pt(II) , which was caught by the 2-pyridyl substituents on the Ni(II) porphyrin. The unique reactivity of the Pt(II) pincer complex led to the formation of a meso-spiro[cyclopentadiene-isoporphyrin].
Angewandte Chemie International Edition 02/2012; 51(13):3174-7. · 13.45 Impact Factor
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ABSTRACT: Switch 'em up: Two-electron oxidation and reduction switches the title complexes between aromatic and antiaromatic character. The switching is confirmed by (1) H NMR and UV/Vis/NIR absorption spectroscopy and by cyclic voltammetry. The structure of the porphyrin-[26]hexaphyrin hybrid tape was elucidated by X-ray diffraction analysis.
Chemistry - An Asian Journal 02/2012; 7(5):889-93. · 4.50 Impact Factor
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ABSTRACT: 5,10,15-Tris(pentafluorophenyl)tetrapyrromethane was efficiently prepared through a route involving stepwise diaroylation of 5-pentafluorophenyldipyrromethane. A(2)B(6)-type [36]octaphyrins were prepared by the cross condensation of the tetrapyrromethane with aryl aldehydes in moderate yields. A(2)B(6)-type [36]octaphyrins bearing 2,4,6-trifluorophenyl, 2,6-dichlorophenyl, and phenyl substituents underwent Cu(II)-metalation-induced fragmentation to give two molecules of AB(3)-type Cu(II) porphyrins. A(2)B(6)-type [36]octaphyrin bearing 3-thienyl substituents underwent thermal N-thienyl fusion reactions to provide a modestly aromatic [38]octaphyrin, which, upon treatment with MnO(2), underwent further N-thienyl fusion and subsequent oxidation to give a nonaromatic doubly N-thienyl fused [36]octaphyrin.
Chemistry - An Asian Journal 01/2012; 7(6):1340-6. · 4.50 Impact Factor
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Angewandte Chemie International Edition 11/2011; 50(48):11460-4. · 13.45 Impact Factor
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ABSTRACT: Hybrid porphyrin tapes 3 and 4, consisting of a mixture of 3,5-di-tert-butylphenyl-substituted donor-type Zn(II)-porphyrins and pentafluorophenyl-substituted acceptor-type Zn(II)-porphyrins, were prepared by a synthetic route involving cross-condensation reaction of a Ni(II)-porphyrinyldipyrromethane and pentafluorophenyldipyrromethane with pentafluorobenzaldehyde followed by appropriate demetalation, remetalation, and oxidative ring-closure reaction. The Ni(II)-substituted porphyrin tapes 5 (Ni-Zn-Ni) and 6 (Ni-H(2)-Ni) were also prepared through similar routes. The hybrid porphyrin tapes 3 and 4 are more soluble and more stable than normal porphyrin tapes 1 and 2 consisting of only donor-type Zn(II)-porphyrins. The solid-state and crystal packing structures of 3, 4, and 5 were elucidated by single-crystal X-ray diffraction analysis. Singly meso-meso-linked hybrid porphyrin arrays 12 and 14 exhibit redox potentials that roughly correspond to each constituent porphyrin segments, while the redox potentials of the hybrid porphyrin tapes 3 and 4 are positively shifted as a whole. The two-photon absorption (TPA) values of 1-6 were measured by using a wavelength-scanning open aperture Z-scan method and found to be 1900, 21,000, 2200, 27,000, 24,000, and 26,000 GM, respectively. These results illustrate an important effect of elongation of π-electron conjugation for the enhancement of TPA values. The hybrid porphyrin tapes show slightly larger TPA values than the parent ones.
Chemistry 11/2011; 17(51):14400-12. · 5.93 Impact Factor
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Chemistry 08/2011; 17(33):9028-31. · 5.93 Impact Factor
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ABSTRACT: Single-molecule photophysical properties of two families of linear porphyrin arrays have been investigated by single-molecule fluorescence detection techniques. Butadiyne-linked arrays (Z(N)B) with extensive π-conjugation perform as photostable one-quantum systems. This demonstration has been suggested by the long-lasting initial emissive state and subsequent discrete one-step photobleaching in the fluorescence intensity trajectories (FITs). As in the behavior of a one-quantum system, Z(N)B shows anti-bunching data in the coincidence measurements. On the other hand, in directly-linked arrays (Z(N)) with strong dipole coupling, each porphyrin moiety keeps individual character in photobleaching dynamics. The stepwise photobleachings in the FITs account for this explanation. Most of the FITs of Z(N) do not carry momentary cessation of fluorescence emission, which has been explained by the strongly bound electron-hole pair of Frenkel exciton that suppresses charge transfer between the molecule and surrounding polymers. These results give insight into the influences of interchromophorinc interactions between porphyrin moieties in the multiporphyrin arrays on their fluorescence dynamics at the single-molecule level.
Chemistry 08/2011; 17(33):9219-25. · 5.93 Impact Factor
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Angewandte Chemie International Edition 06/2011; 50(25):5691-4. · 13.45 Impact Factor
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ABSTRACT: In this study, we have investigated the excited-state energy deactivation dynamics of extended π-conjugated molecular systems that consist of competitive electronic and vibrational relaxation processes.
Chemical Communications 03/2011; 47(15):4433-5. · 6.17 Impact Factor
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Chemistry 11/2010; 16(45):13320-4. · 5.93 Impact Factor
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ABSTRACT: A porphyrin nanobarrel, 1, that can encapsulate C(60) effectively was prepared via a concise coupling route. The structures of both 1 and C(60)@1 were confirmed by single-crystal X-ray diffraction analysis.
Journal of the American Chemical Society 10/2010; 132(46):16356-7. · 9.91 Impact Factor
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ABSTRACT: A beta,beta'-doubly 2,6-pyridylene-bridged porphyrin dimer and trimer were prepared by Suzuki-Miyaura coupling reactions and confirmed to have largely bent structures. These oligoporphyrins were readily metalated via meso-C-H bond activation with the assistance of the pyridyl nitrogen atoms to produce the corresponding Pd(II) complexes, which display even larger bent structures and larger TPA values at 800 nm.
Journal of the American Chemical Society 09/2010; 132(34):11868-9. · 9.91 Impact Factor
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Angewandte Chemie International Edition 05/2010; 49(21):3617-20. · 13.45 Impact Factor
