Porphyrin nanochannels reinforced by hydrogen bonding.
Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8571, Japan.Chemical Communications (Impact Factor: 6.38). 05/2012; 48(52):6481-3. DOI:10.1039/c2cc31142a
ABSTRACT Carboxyl groups were introduced at the peripheral positions of dodecaphenylporphyrin to link nanochannel structures with intermolecular hydrogen bonds to make the supramolecular structures robust.
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ABSTRACT: Kinetics of photoinduced electron transfer from a series of electron donors to the triplet excited states of a series of nonplanar porphyrins, hydrochloride salts of saddle-distorted dodecaphenylporphyrin ([H(4)DPP]Cl(2)), tetrakis(2,4,6-trimethylphyenyl)porphyrin ([H(4)TMP]Cl(2)), tetraphenylporphyrin ([H(4)TPP]Cl(2)), and octaphenylporphyrin ([H(4)OPP]Cl(2)), were investigated in comparison with those of a planar porphyrin, zinc [tetrakis(pentafluorophenyl)]porphyrin [Zn(F(20)TPP)(CH(3)CN)], in deaerated acetonitrile by laser flash photolysis. The resulting data were evaluated in light of the Marcus theory of electron transfer, allowing us to determine reorganization energies of electron transfer to be 1.21 eV for [H(4)TMP]Cl(2), 1.29 eV for [H(4)TPP]Cl(2), 1.45 eV for [H(4)OPP]Cl(2), 1.69 eV for [H(4)DPP]Cl(2), and 0.84 eV for [Zn(F(20)TPP)(CH(3)CN)]. The reorganization energies exhibited a linear correlation relative to the out-of-plane displacements, which represent the degree of nonplanarity. The rate of electron-transfer reduction of diprotonated porphyrins is significantly slowed down by conformational distortions of the porphyrin ring. This indicates that the reorganization energy of electron transfer is governed by structural change, giving a larger contribution of inner-sphere bond reorganization energy rather than outer-sphere solvent reorganization energy.Journal of the American Chemical Society 01/2009; 131(2):577-84. · 10.68 Impact Factor
- Chemical Reviews 02/2008; 108(1):1-73. · 41.30 Impact Factor
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ABSTRACT: The development of anhydrous proton-conductive materials operating at temperatures above 80 degrees C is a challenge that needs to be met for practical applications. Herein, we propose the new idea of encapsulation of a proton-carrier molecule--imidazole in this work--in aluminium porous coordination polymers for the creation of a hybridized proton conductor under anhydrous conditions. Tuning of the host-guest interaction can generate a good proton-conducting path at temperatures above 100 degrees C. The dynamics of the adsorbed imidazole strongly affect the conductivity determined by (2)H solid-state NMR. Isotope measurements of conductivity using imidazole-d4 showed that the proton-hopping mechanism was dominant for the conducting path. This work suggests that the combination of guest molecules and a variety of microporous frameworks would afford highly mobile proton carriers in solids and gives an idea for designing a new type of proton conductor, particularly for high-temperature and anhydrous conditions.Nature Material 10/2009; 8(10):831-6. · 35.75 Impact Factor
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