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Bucky gels are gelatinous composite materials consisting of carbon nanotubes and ionic liquids. This article gives an overview of some promising applications of bucky gels reported mostly in the last few years and a possible extension to the dispersion of graphene sheets.

The optical antipodes of chiral p-xylylene-, m-xylylene-, and dodecamethylene-strapped porphyrins were resolved by HPLC. Asymmetric epoxidation of prochiral olefins such as styrene derivatives and vinylnaphthalene by iodosobenzene was achieved by using the manganese complexes of the antipodes of p-xylylene-strapped porphyrin as catalysts in the presence of imidazole, and the optically active epoxides were obtained in 42-58% ee enantiomeric excess). When imidazole was absent, the epoxides with the opposite configuration were formed in lower ee

By using the manganese complexes of the antipodes of the conceptually new chiral strapped porphyrin as catalysts coupled with imidazole, asymmetric epoxidation of prochiral olefins by iodosobenzene was achieved. When the external ligand was absent, the epoxides with the opposite configuration were formed in lower % e.e. In the presence of the external ligand, the enantioselectivity of the reaction depended on the structure of the strap in the catalyst, while no such dependence was observed in the absence of imidazole. The iron complex of chiral p -xylylene-strapped porphyrin effectively catalysed the asymmetric oxidation of sulfides by iodosobenzene in the presence of imidazole.

The first axially dissymmetric pyrroles, 4-methyl-3-(2′-methoxy-1′-naphthyl)pyrrole-2-carboxylates 1, were synthesized, characterized by X-ray crystallography and circular dichroism analysis, and applied to the first ‘predetermined’ synthesis of a chiral atropisomeric porphyrin with molecular asymmetry, (R,R,R,R)- and (S,S,S,S)- 2,7,12,17-tetramethyl-3,8,13,18-tetrakis(2′-methoxy-1′-naphthyl)porphyrin

The living polymerization of methacrylic esters initiated with aluminium porphyrins was found to be dramatically accelerated upon the addition of organoaluminium or organoboron compounds as a Lewis...

Chiral N-substituted porphyrin free bases having a conformationally locked asymmetric nitrogen atom catalyzed Michael addition of thiophenols to cycloalkenones, where the reaction proceeded enantioselectively when the catalyst having a xylylene strap anchored via two secondary amido linkages (2) was employed.

Under irradiation with visible light, oxophosphorous porphyrins [(EtioP)PR(=O), 1 (R = Ph) and 2 (R = Et); EtioP = etioporphyrinato I] and phenyl(methoxy)phosphorous porphyrin chloride [[(EtioP)PPh(OMe)]Cl, 3] catalyzed hydration of benzonitrile to benzamide in alkaline methanol.

A chirality-memorizing saddle-shaped porphyrin ( 1 2H ) with 3,5-dipyridylphenyl side arms at the opposite meso positions underwent supramolecular polymerization in CH 2 Cl 2 with a chiral Pd(II) complex of 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (Pd II (BINAP)), forming a ladder-shaped polymer ( 3 2H ) with a prevailing one-handed helical chirality. When this polymer was poured into AcOH containing 1,3-bis(diphenylphosphino)propane (DPPP) as a decomplexing agent, 3 2H was depolymerized in a stereochemically retentive way to give optically active 1 2H , hydrogen-bonded with AcOH. Although a cyclodimeric reference of 3 2H , formed from 2 2H having two 3-pyridylphenyl meso substituents in conjunction with Pd II (BINAP), behaved similar to 3 2H , the translation efficiency of helical chirality was lower than that in the case with 3 2H .

Ferrocene, a double-decker organometallic compound that generates angular motion, can be used as a unique rotary module for molecular machines. By interlocking a ferrocene-based rotary module with a photochromic unit, we have developed novel molecular machines that operate via power-conversion mechanisms. This design strategy, which mimics real machines in our daily life, allows for remote control of molecular events.

This review article describes graphitic nanotubular objects formed by programmed self-assembly of Gemini-shaped hexa-peri-hexabenzocoronene (HBC) derivatives. The nanotubes are characterized by an aspect ratio greater than 1000 and have a uniform diameter of 20 nm, which is an order of magnitude larger than those of carbon nanotubes. The wall of the nanotubes consists of a helical array of the π-stacked graphene molecules. The inner and outer surfaces of the nanotubes are covered by hydrophilic triethylene glycol chains. Upon oxidation, the graphitic nanotubes become electroconductive. Modifications of the chemically accessible surface result in the formation of nanotubes with various properties.

Recent progress in fundamental studies on multiporphyrin arrays has provided structural parameters for the molecular design of artificial light-harvesting antennae which mimic the wheel-like antenna complexes of photosynthetic purple bacteria. Covalent and noncovalent approaches have been employed for the construction of artificial light-harvesting multiporphyrin arrays. Such arrays are categorized into ring-shaped, windmill-shaped, star-shaped, and dendritic architectures. In particular, dendritic multiporphyrin arrays have been proven to be promising candidates for both providing a large absorption cross-section and enabling the vectorial transfer of energy over a long distance to a designated point. Such molecular and supramolecular systems are also expected to be potent components for molecular electronics and photonic devices.

Cobalt(II) complexes of poly(aryl ester) dendrimer porphyrins [(m-[Gn]TPP)Co(II)] (generation number n=0-4), in the presence of azobisisobutyronitrile (AIBN) at 60 degrees C, underwent alkenylation with several alkynes at the metal center. A complete inhibition of double-bond migration (secondary transformation) was observed for [(m-[Gn]TPP)Co(II)] (n=3 and 4), which gave [(m-[Gn]TPP)Co(III)-C(=CH(2))R] (n=3 and 4) exclusively. Overall reaction rates for [(m-[Gn]TPP)Co(II)] (n=0-3) were hardly dependent on the size of the dendritic substituents, while a notable retardation was observed for the largest dendrimer, [(m-[G4]TPP)Co(II)]. Mechanistic studies on double-bond migration with pure [(m-[Gn]TPP)Co(III)-C(=CH(2))Bu] (n=0-4) demonstrated that the secondary transformation involves participation of [(m-[Gn]TPP)Co(III)H] (n=0-4), derived from [(m-[Gn]TPP)Co(II)] and AIBN, rather than [(m-[Gn]TPP)Co(II)] alone. Crossover experiments using [(m-[Gn]TPP)Co(III)-C(=CH(2))Bu] (n=2-4), in combination with nondendritic [(m-[G0]TPP)Co(II)] and AIBN, indicated a high level of steric protection of the active center by a robust [G4]-dendritic cage, as suggested by a (1)H NMR pulse relaxation time profile of m-[G4]TPPH(2).

Apoprotein of horse-heart myoglobin promoted enantioselective hydrolysis of 4-nitrophenyl esters of amino acids, which allowed nearly perfect kinetic resolution of racemic N-Boc-phenylalanine ester (Boc-Phe-ONp).

This short review focuses on recent advances in controlled polymerization and macromolecular architectonics by means of a variety of organized media with constrained geometries.

Irradiation with visible light induced a remarkable effect on the reactivity of a metal-carbon bond in (tetraphenylporphinato)aluminum methyl in the nucleophilic substitution reaction with protic compounds such as phenol. A similar photoacceleration effect was also observed in the reversible ligand exchange of (tetraphenylporphinato)aluminum phenoxide with phenol. As for the former reaction, comparable quantum yields were observed upon irradiation at the Soret band and at the Q-band. 22 refs., 5 figs.

Photocatalysis with metalloporphyrin has been studied mainly in connection with biological photosynthesis. Electron transfer from excited metalloporphyrin to an acceptor resulting in charge separation, eventually leading to hydrogen evolution from water, has been the subject of much interest. In the present communication, they report an unprecedented type of the photocatalysis with metalloporphyrin, in which the formation of carbon-carbon bonds proceeds by the effect of visible light. The reaction is the polymerization of alkyl methacrylate catalyzed by (tetraphenylporphinato)aluminum methyl((TPP)AlMe) upon irradiation with visible light to give a polymer of narrow molecular weight distribution.